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  • 1985-1989  (597)
  • 1950-1954
  • 1985  (597)
  • Physics  (479)
  • Physical Chemistry  (118)
  • 1
    Electronic Resource
    Electronic Resource
    Erratum (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 254-254 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170209
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  • 2
    Electronic Resource
    Electronic Resource
    Comprehensive Chemical Kinetics, volume 24, modern methods in kinetics, C.H. bamford and C.F.H. tipper, Eds. Elsevier, Amsterdam, 1983. 528 pp. (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 255-255 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170210
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  • 3
    Electronic Resource
    Electronic Resource
    Hydrogen abstraction from substituted aromatic compounds (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 265-269 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactivity of tert-butoxy radicals with methyl substituted aromatic compounds is almost exclusively determined by the aromatic moiety and almost independent of the methyl group position. The hydrogen abstraction from the carbon α to the aromatic ring is hardly sensitive to the produced radical stabilization. This lack of dependence can be explained in terms of the large exothermicity of the process.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170303
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  • 4
    Electronic Resource
    Electronic Resource
    Kinetics of the reactions of hydroxyl radical with aliphatic aldehydes (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 303-313 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Rate coefficients for OH reactions with the 2-5 carbon aliphatic aldehydes have been measured under pseudo first-order conditions in OH. OH was generated by flash photolysis of H2O at wavelengths greater than 165 nm and its concentration monitored using time-resolved resonance fluorescence spectroscopy. Two reactions were studied only at 298 K while five reactions were studied over the temperature range 250-425 K; negative activation energies were observed for all five reactions. Aldehyde reactivity toward OH is nearly independent of the identity of the hydrocarbon side chain. Our results are compared with those obtained in previous studies of OH-aldehyde reaction kinetics and their mechanistic implications are discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170307
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  • 5
    Electronic Resource
    Electronic Resource
    Disproportionation reactions between alkyl and fluoroalkyl radicals. III. A reassessment of Δ values for CFyH(3-y) radicals (y = 1,2,3) with C2H5 radicals (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 327-335 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New determinations of the disproportionation and combination ratios between CF2H and C2H5 radicals yield (the hydrogen acceptor radical is given first) Δ(CF2H, C2H5) = 0.068 ± 0.008, and Δ(C2H5, CF2H) = 0.37 ± 0.01. A reevaluation of the existing data on CFH2 and CF3 radicals leads to the following recommended values, Δ(CFH2, C2H5) = 0.038 ± 0.006, and Δ(CF3, C2H5) = 0.11 = ± 0.02.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170309
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  • 6
    Electronic Resource
    Electronic Resource
    The electronic effects of substituents at the acyl carbon in the gas-phase elimination kinetics of tert-butyl α-substituted acetates (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 337-343 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The gas-phase eliminations of several tert-butyl esters, in a static system and in vessels seasoned with allyl bromide, have been studied in the temperature range of 171.5-280.1°C and the pressure range of 23-98 torr. The rate coefficients for the homogeneous unimolecular elimination of these esters are given by the following Arrhenius equations: for tert-butyl pivalate, log k1(s-1) = (13.44 ± 0.30) - (169.1 ± 3.1) kJ · mol-1 (2.303RT)-1; for tert-butyl trichloroacetate, log k1(s-1) = (12.41 ± 0.08) - (141.1 ± 0.7) kJ · mol-1 (2.303RT)-1; and for tert-butyl cyanoacetate log k1(s-1) = (11.31 ± 0.44) - (137.8 ± 4.1) kJ · mol-1 (2.303RT)-1. The data of this work together with those reported in the literature yield a good linear relationship when plotting log k/k0 vs. σ* values (ρ* = 0.635, correlation coefficient r = 0.972, and intercept = 0.048 at 250°C). The positive ρ* value suggests that the movement of negative charge to the acyl carbon in the transition state is rate determining. The present results along with previous investigations ratify the generalization that electron-withdrawing substituents at the acyl side of ethyl, isopropyl, and tert-butyl esters enhance the elimination rates, while electron-releasing groups tend to reduce them. The negative nature of the acyl carbon and the polarity in the transition state increases slightly from primary to tertiary esters.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170310
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  • 7
    Electronic Resource
    Electronic Resource
    Reactivities of cis- and trans-buten-2-yl free radicals in presence of D2S. II. Absolute values of rate constants and isotopic effects (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 389-399 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cis- and trans-buten-2-yl free radicals are shown to react with butene-2 cis (Bc) and D2S in the following metathetical steps: giving rise to butenes-1 (B1). The initial formations of butene-1,3 d1 and total butene-1 in D2S—Bc mixtures have been studied in the initial pressure range 20-200 torr for Bc, 0-41 torr for D2S and at 717-817 K. The main initiation and termination steps are shown to be: Assuming a rapid equilibrium between cis- and trans-C4H7⋅, ki ≃ 1015.5 exp(-85.5/RT) s-1 (RT in kcal mol-1) and kt ≃ 1013 mol-1 cm3 s-1, we get: k2c′ = 1.1 k2t′ = 1012.0 exp[(-9.25 ± 2)/RT] mol-1 cm3 s-1 and k2 + 1.5 k2′ ≃ 1012.1 exp[(-15.2 ± 2)/RT] mol-1 cm3 s-1. Isotopic effects relating to processes (2c′) + (2t′) and to (i′) have been evaluated.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170405
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  • 8
    Electronic Resource
    Electronic Resource
    The steady-state oxidation of CO on rhodium(100)This work was supported in part by the Robert A. Welch Foundation (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 413-417 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In this article, we present low-pressure steady-state results for carbon monoxide oxidation over Rh(100). The results are comparable to those found for other Group VIII transition metals. For a fixed oxygen pressure, the reaction rate is first order in CO pressure until a critical pressure is reached, above which the reaction rate sharply diminishes and the order becomes negative in CO pressure. Coverages of carbon monoxide under steady-state working conditions have been measured.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170407
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  • 9
    Electronic Resource
    Electronic Resource
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170501
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  • 10
    Electronic Resource
    Electronic Resource
    The reactions of alkoxy radicals with O2. II. n-C3H7O radicals (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 477-501 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: n-C3H7ONO was photolyzed with 366 nm radiation at -26, -3, 23, 55, 88, and 120°C in a static system in the presence of NO, O2, and N2. The quantum yields of C2H5CHO, C2H5ONO, and CH3CHO were measured as a function of reaction conditions. The primary photochemical act is and it proceeds with a quantum yield φ1 = 0.38 ± 0.04 independent of temperature. The n-C3H7O radicals can react with NO by two routes The n-C3H7O radical can decompose via or react with O2 via Values of k4/k2 ≃ k4b/k2 were determined to be (2.0 ± 0.2) × 1014, (3.1 ± 0.6) × 1014, and (1.4 ± 0.1) × 1015 molec/cm3 at 55, 88, and 120°C, respectively, at 150-torr total pressure of N2. Values of k6/k2 were determined from -26 to 88°C. They fit the Arrhenius expression: \documentclass{article}\pagestyle{empty}\begin{document}$$ \log (k_6 /k_2) = - 2.17 \pm 0.20 - (879 \pm 117)/2.303{\rm T}{\rm .} $$\end{document} For k2 ≃ 4.4 × 10-11 cm3/s, k6 becomes (2.9 ± 1.7) × 10-13 exp{-(879 ± 117)/T} cm3/s. The reaction scheme also provides k4b/k6 = 1.58 × 1018 molec/cm3 at 120°C and k8a/k8 = 0.56 ± 0.24 independent of temperature, where
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550170503
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  • 11
    Electronic Resource
    Electronic Resource
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170601
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  • 12
    Electronic Resource
    Electronic Resource
    Principal component analysis of kinetic models (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 55-81 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An eigenvalue-eigenvector analysis is used to extract meaningful kinetic information from linear sensitivity coefficients computed for several species of a reacting system at several time points. The main advantage of this method lies in its ability to reveal those parts of the mechanism which consist of strongly interacting reactions, and to indicate their importance within the mechanism. Results can be used to solve three general kinetic problems. Firstly, an objective condition for constructing a minimal reaction set is presented. Secondly, the uncovered dependencies among the parameters are shown to confirm or deny validity of quasi-steady-state assumptions under the considered experimental conditions. Thirdly, taking into account only sensitivities of observed species, the analysis is used to yield error estimates on unknown parameters determined from the experimental observations, and to suggest the parameters that should be kept fixed in the estimation procedure. To illustrate we chose the well-known hydrogen-bromine reaction and the kinetics of formaldehyde oxidation in the presence of CO.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170107
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  • 13
    Electronic Resource
    Electronic Resource
    Homolytic substitution in trialkyltin iodides by photochemically generated iodine atoms. I. Kinetics (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 95-108 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the homolytic substitution of several trialkyltin iodides by iodine atoms are presented. Rate constants have been determined at three different temperatures and the following activation parameters calculated: A, Ea, and ΔS°≠. The observation that the activation energy, ΔG≠, is related to the driving force of the ion-pair formation, leads to the conclusion that the charge-transfer model is a valid approach for substitution in the reaction between R3SnI compounds and iodine atoms.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170109
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  • 14
    Electronic Resource
    Electronic Resource
    Decomposition of di-tert-butyl nitroxide in aqueous solutions (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 109-116 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Di-tert-butyl nitroxide (DTBN) decomposes in aqueous solutions producing 2-methyl-2-nitroso propane (MNP) and tert-butanol. The process is acid catalyzed, it is of second order in DTBN, and takes place with a rate constant of (1.0 ± 0.1) M-2 s-1. The reaction is also catalyzed by the anionic surfactant sodium dodecyl sulfate and by Fe(II) and Fe(III) ions. The catalysis by Fe(III) involves a very fast reduction of Fe(III) ions with concomitant formation of 2-methyl-2-nitroso propane. The reaction catalyzed by Fe(II) also produces 2-methyl-2-nitroso propane with a formation rate given by: d[MNP]/dt = (0.25 ± 0.10) [Fe(II)] [DTBN]. This reaction rate is nearly pH independent.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170110
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  • 15
    Electronic Resource
    Electronic Resource
    Kinetics of interaction of vibrationally excited OH(X2πi)v=9 with simple hydrocarbons at room temperature (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 613-628 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Relative rate constants for the removal of vibrationally excited OH in the ninth vibrational level of its ground electronic state [designated hereafter by OH† (9)] by interaction with a series of simple hydrocarbons at room temperature are reported. The reaction of hydrogen atoms with ozone was used to generate OH†(9) in a fast flow discharge system at 1.1 ± 0.1 torr total pressure. The decrease in the (9 → 3 band) Meinel band chemiluminescent emission intensity at 626 nm was followed as a function of the concentration of added organic or of a reference deactivator (O2), respectively, at a fixed reaction time; these data gave relative rate constants, k2X/k2O2, for the removal of OH†(9) by the organic. The relative rate constants determined in this study are as follows: C2H6, 2.7 ± 0.2; C3H8, 4.4 ± 0.4; n-C4H10, 7.5 ± 0.6; iso-C4H10, 7.3 ± 0.8; n-C5H12, 10.4 ± 0.7; C2H4, 22.9 ± 1.8; C3H6, 43.4 ± 1.4; cis-2-C4H8, 47.7 ± 3.1; C6H6, 29 ± 7. (Errors are two standard deviations of the weighted mean of experiments in two flow tubes with different wall coatings and carrier gases.) The implications of the trends in these rate constants for the relative contributions of energy transfer and reaction to the net removal of OH† (9) are discussed.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170607
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  • 16
    Electronic Resource
    Electronic Resource
    A biradical calculation model for the thermal dimerization of cyclohexa-1,3-diene in the gas phase (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 709-711 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170612
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  • 17
    Electronic Resource
    Electronic Resource
    Heat of formation of the vinyl radical (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 831-833 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170804
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  • 18
    Electronic Resource
    Electronic Resource
    Kinetics of oxidation of some α-amino acids L(-) arginine, L(-) histidine, L(+) ornithine, L(-) tryptophan, L(-) threonine by sodium N-chloro-4 methyl benzene sulphonamide (chloramine-T) in alkaline medium (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 769-785 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetic studies of oxidation of L(-) arginine, L(+) ornithine, L(-) histidine, L(-) tryptophan, L(-) threonine have been carried out in alkaline medium. The reaction showed an inverse fractional order in OH- and first-order dependence on both amino acid and chloroamine-T concentration. The effect of varying ionic strength (KCl) on the rate of oxidation is negligible. A general mechanism for the oxidation has been suggested by considering interaction between anionic species of amino acid and p-toluene-sulphochloramide. The effect of solvent and temperature have been also discussed. The fractional order obtained in OH- is due to the fact that a fraction of overall reaction proceeds via an alternative OH- independent path. The combined rate law in accordance to observed kinetics is derived as \documentclass{article}\pagestyle{empty}\begin{document}$$ - \frac{{d[{\rm CAT}]}}{{dt}} = \frac{{2k_1 K_1 [{\rm AA}]_T [{\rm CAT}]_T }}{{[{\rm OH}^ - ]}} + 2k_3 K_1 K_3 [{\rm AA}]_T [{\rm CAT}]_T $$\end{document} The rate constants predicted by the derived rate law as the concentration of OH- ions change, are in excellent agreement with the observed rate constants, thus further justifying these rate laws and hence the proposed mechanistic schemes.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550170707
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  • 19
    Electronic Resource
    Electronic Resource
    Masthead (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985) 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170901
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  • 20
    Electronic Resource
    Electronic Resource
    N2O5 photolysis products investigated by fluorescence and optoacoustic techniques (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 991-1006 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Pulsed laser photolysis of N2O5 near 290 nm coupled with fluorescence detection (calibrated by NO2 photolysis) showed that the O(3P) quantum yield is ≤0.1. A pulsed laser optoacoustic technique in a flow tube (ca. 6 torr of N2) was tested by photolysis of NO2 and then applied to N2O5. Nitric oxide was added to react with NO3 free radical and the resulting increase in the optoacoustic signal confirmed the presence of NO3 free radicals. Based on the relative optoacoustic signals observed for NO2 and N2O5, the quantum yield for NO3 production is 0.8 ± 0.2.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550170906
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  • 21
    Electronic Resource
    Electronic Resource
    Effects of ring strain on gas-phase rate constants. 3. NO3 radical reactions with cycloalkenes (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 957-966 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Rate constants for the gas-phase reactions of NO3 radicals with a series of cycloalkenes have been determined at 298 ± 2 K, using a relative rate technique. Using an equilibrium constant for the NO2 + NO3 ⇄ N2O5 reactions of 3.4 × 10-11 cm3 molecule-1, the following rate constants (in units of 10-13 cm3 molecule-1 s-1) were obtained: cyclopentene, 4.52 ± 0.52; cycloheptene, 4.71 ± 0.56; bicyclo[2.2.1]-2-heptene, 2.41 ± 0.28; bicyclo[2.2.2]-2-octene, 1.41 ± 0.17; bicyclo[2.2.1]-2,5-heptadiene, 9.92 ± 1.13; and 1,3,5-cycloheptatriene, 12.6 ± 2.9. When combined with previous literature rate constants for cyclohexene and 1,4-cyclohexadiene, these data show that the rate constants for the nonconjugated cycloalkenes studied depend to a first approximation on the number of double bonds and the degree and configuration of substitution per double bond. No obvious effects of ring strain energy on these NO3 radical addition rate constants were observed. Our previous a priori predictive techniques for the alkenes and cycloalkenes can now be extended to strained cycloalkenes.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550170904
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  • 22
    Electronic Resource
    Electronic Resource
    Studies on the rate of isotopic oxygen exchange between [Re(py)4O2]+ and solvent water (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1007-1015 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The rate of oxygen exchange between trans-[Re(py)4O2]+ and solvent water in pypyH+ buffer solution follows simple first-order kinetics and both oxygens are equivalent. The half-life for isotopic oxygen exchange is about 12 h at a pH of 5.0, 25°C, and [py] = 0.10 M. The observed rate constant for exchange increases with acidity, in the pH range 4 to 6, decreases with [py], and is nearly independent of ionic strength. A small but significant increase of kobs occurs with increasing complex concentration. The rate of exchange follows the rate equation kobs/2 = k0 + k1/[py] with k0 = 1.4 × 10-5(2) s-1 and k1 = 4.7 × 10-7(1) M, s-1 at 25°C. The activation parameters for the reaction at pH = 7.15 (predominately the k0 term) are: ΔH* = +137.(1) kJ/M and ΔS* = +126.(1) J/MK. The pH effect and complex concentration effect are discussed in mechanistic terms. These results are compared to those found for [Re(en)2O2]+ and [Re(CN)4O2]3-.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550170907
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  • 23
    Electronic Resource
    Electronic Resource
    The agent of the autocatalytic thermal decomposition of aliphatic nitrate ester explosives (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1085-1090 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The condensed-phase thermal decomposition of aliphatic nitrate ester explosives is generally autocatalytic. The object of this article is to show that the agent of the autocatalysis is not the product NO2, as is generally believed, but to suggest that it may be the product formaldehyde.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550171005
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  • 24
    Electronic Resource
    Electronic Resource
    Mechanism of the silane decomposition. I. Silane loss kinetics and rate inhibition by hydrogen. II. Modeling of the silane decomposition (all stages of reaction) (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1029-1065 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Part I: Kinetic data for the static system silane pyrolysis (from 640-703 K, 60-400 torr) are presented. For conversion from 3-30%, first-order kinetics are obtained, with silane loss rates equal to half the hydrogen formation rates. At conversions greater than 40%, rate inhibition attributable to the back reaction of hydrogen with silylene occurs. Overall reaction rates are not surface sensitive, but disilane and trisilane yield maxima under some conditions are. A nonchain mechanism capable of describing quantitatively all stages of the silane pyrolysis is proposed. Post 1.0% initiation is both homogeneous (gas phase) and heterogeneous (on the walls), and reaction intermediates are silylenes and disilenes. Free radicals are not involved at any stage of the reaction. Rate data at high conversions and with added hydrogen provide kinetics for the addition of silylene to hydrogen [reaction (-1)1] relative to its addition to silane [reaction (2)]: k-1,/k2 = 10-0.65 × e-3200 cal/RT. With E2 = 1300 cal, this gives a high pressure activation energy for silylene insertion into hydrogen of E-1 = 8200 cal.Part II: An analysis is made of each rate constant of the silane mechanism and the modeling results are compared with experimental results. Agreement is excellent. It is concluded that the dominant sink reaction for silylene intermediates is 1,2 - H2 elimination from disilane (followed by Si2H4 polymerization and wall deposition). The model is in accord with slow isomerization between disilene and silylsilylene and near exclusive 1,2 - H2 elimination from Si2H6. It is also concluded that disilene is about 10 kcal/mol more stable than silylsilylene and that the activation energy for isomerization of silylsilylene to disilene is greater than 26 kcal/mol.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550171003
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  • 25
    Electronic Resource
    Electronic Resource
    Comments on the linear relation between reaction rate and affinity (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1119-1123 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In the case of catalytic dehydrogenation of cyclohexane, the linear relation between reaction rate and affinity holds at an appreciable distance away from equilibrium on both sides. In fact, in order to explain this observation, it is necessary to invoke a high value of three for the stoichiometric number of the rate determining step. This in turn can be explained by a reasonable mechanism for the reaction.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550171008
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  • 26
    Electronic Resource
    Electronic Resource
    Rate constants for the quenching of metastable O2(1Σg+) molecules (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1155-1167 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Singlet molecular oxygen, O2(1Σg+), is one of the important intermediate species in the atmospheres of Earth, Mars, and Venus. To elucidate the chemistry of this excited molecular oxygen, a series of kinetic measurements have been undertaken using the flow-discharge/optical-emission technique. By monitoring the characteristic emission (762 nm for 1Σg+), the quenching rates for several important molecules have been obtained at room temperature. The following table summarizes measurements. TextQuencherRate Constants (cm3/s)CH2(4.6 ± 0.5) × 10-13H2(7.0 ± 0.3) × 10-13N2(1.7 ± 0.1) × 10-15Cl2(4.5 ± 0.8) × 10-16CO(4.5 ± 0.5) × 10-15O3(2.2 ± 0.3) × 10-112,3 DBM-2(6.0 ± 0.1) × 10-13The error limits represent one standard deviation. The systematic error is estimated to be about 15%. For CO2 and O3 molecules, the quenching rate constants were also measured in the temperature range of 245-362 K. In both reactions, negligible temperature dependences (with the activation energy less than 0.6 kcal/mole) were observed.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550171102
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  • 27
    Electronic Resource
    Electronic Resource
    Deuterium isotope cage effects in the dismutation of alkoxyl radicals. Significance for the mode of alkylperoxyl termination (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1187-1190 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Decomposition of (R1R2CXON=)2 (R1 = R2 = Ph; R1 = R2 = p—ClC6H4; R1 = Ph, R2 = CH3; X = H or D) in hydrocarbon solvents at 31-75°C afforded R1R2CO in 6-8% lower yield when X = D than when X = H. This result is ascribed to cage escape of secondary alkoxyl radicals in competition with dismutation. Deuterium isotope effects for alkoxyl cage dismutation of 1.35-2.4 are estimated from the data. It is suggested that this same competition may account for the experimentally slower termination rate constants in solution of primary and secondary alkylperoxyl radicals on α-deuteration.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/kin.550171104
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  • 28
    Electronic Resource
    Electronic Resource
    Thermal decomposition of methane: Autocatalysis (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 967-990 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The origin of autocatalysis in the pyrolysis of methane has been investigated by kinetic modeling. A mechanism is presented that provides good agreement with experimental data at 1038 K and 433 torr into the autocatalytic region. The main causes of autocatalysis are secondary initiation by hydrocarbon products larger than C2H6 and chain radical methylation sequences.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550170905
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  • 29
    Electronic Resource
    Electronic Resource
    Mechanism and kinetics of the silane decomposition in the presence of acetylene and in the presence of olefins (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1067-1083 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Kinetic data and product studies are reported for the silane pyrolysis in the presence of olefins and acetylene. The kinetics of silane loss in the presence of acetylene was found to be identical to the initial gas phase silane decomposition step (SiH4 + M → SiH2 + H2 + M) when corrected for pressure fall-off effects. This result and the absence of methane or ethane from the pyrolysis of SiH4 in the presence of 1-butene or 1-pentene demonstrate that silyl radicals and H atoms are not involved in silane-olefin or silane-acetylene reactions. Qualitative aspects and kinetic data from the SiH4 pyrolysis in the presence of propylene are in accord with propylsilane formation via propylsilylene formed by silylene addition to propylene.
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  • 30
    Electronic Resource
    Electronic Resource
    Excimer laser perturbations of methane flames: High temperature reactions of OH and CH (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1103-1118 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An ArF excimer laser was used to perturb radical concentrations and a tunable dye laser was used to follow the rise and subsequent decay of OH and CH in rich (φ = 1.6-1.8) atmospheric pressure methane flames. The excimer beam is only slightly focussed to minimize temperature excursions and the influence of diffusion and convection on the decay rates. The observed OH decay is consistent with that predicted using a detailed kinetic mechanism. The observed CH decay is much faster than predicted. The effects of equivalence ratio and height above burner suggests that a major CH decay channel involving an intermediate with higher concentration in rich flames is not properly treated in the mechanism.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550171007
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  • 31
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    Electronic Resource
    Erratum (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1153-1154 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550171011
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  • 32
    Electronic Resource
    Electronic Resource
    High temperature measurements of the rate of the reaction of OH with NH3 (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1191-1199 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Low pressure (4.67 kPa) CH4/O2/Ar flames were seeded with approximately 5300 ppm NH3. The concentration profiles of stable and radical species in lean (φ = 0.92) and rich (φ = 1.13) flames were determined by molecular beam sampling mass spectrometry. Temperature profiles in these flames were measured with thermocouples whose readings were corrected for radiative losses by the Na-line reversal method. Regions of the flames were selected where the principal reaction leading to the destruction of NH3 was By correcting the measured concentrations for diffusion, the net rate of NH3 loss rate was determined in the temperature range 2080-2360 K. The rate constant k1 was determined from the net loss rate with correction for the reaction using measured values of (O) and k2 values given by Salimian, Hanson, and Kruger [1]. The best-fit Arrhenius expression for k1 in the temperature range 2080-2360 K is 1013.88 exp(-4539/T) cm3/mol-s. The results of this study combined with previous lower temperature data confirm the non-Arrhenius behavior of k1 suggested by Salimian, Hanson, and Kruger [1]. The best-fit modified three parameter expression for the range 300-2360 K is 106.33±0.2 T2 exp(-169/T) cm3/mol-s.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550171105
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  • 33
    Electronic Resource
    Electronic Resource
    Yields of O2(b1Σg+) from reactions of HO2 (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1169-1185 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A discharge-flow apparatus with resonance fluorescence and chemiluminescence detection has been used to monitor O2(b 1σg+) production from several reactions of the HO2 radical at 300 K and 1-torr total pressure. O2(b), HO2, and OH were observed when F atoms were added to H2O2 in the gas phase. Signal strengths of O2(b) were proportional to initial concentrations of H2O2 and HO2. These observations were analyzed by using a simple three step mechanism and a more complete computer simulation with 22 reaction steps. The results indicate that the F + HO2 reaction yields O2(b) with an efficiency of (3.6 ± 1.4) × 10-3. By monitoring [O2(b)] and [HO2] upon addition of an excess second reactant to HO2, O2(b) yields from the reactions of HO2 with O, Cl, D, H, and OH were found to be 〈1 × 10-2, 〈5 × 10-4, 〈2 × 10-3, 〈8 × 10-3, and 〈1 × 10-3, respectively. Yields of O2(b) from the HO2 ± HO2 reaction were found to be less than 3 × 10-2.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550171103
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    Electronic Resource
    Electronic Resource
    A kinetic study of the chlorination of tertiary alcoholamines in alkaline media (1985)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 17 (1985), S. 1231-1245 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the chlorination of various tertiary alcoholamines by hypochlorite have been studied in alkaline media. A reaction mechanism consistent with the experimental results is put forward, and a relationship is established between the rate constants and the polar parameter (Σσ*) of the substituents.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/kin.550171109
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  • 35
    Electronic Resource
    Electronic Resource
    Quantum yield for poly(methyl methacrylate) chain scission by 214-229 nm wavelength light (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1749-1758 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The quantum yield for poly(methyl methacrylate)chain scission by ultraviolet light in the 214-229 nm wavelength region was found to be φd = 0.03 scissions per absorbed photon. Samples were 1.65-μm films spun cast on silicon wafers and irradiated under flowing nitrogen by a cadmium vapor lamp. Gel permeation chromatography was used for molecular weight determination. Heating (postbaking) the irradiated films at 150°C for one hour under reduced-pressure flowing nitrogen increased the observed scissions per absorbed photon to 0.04. Glass transition temperatures by DSC are well-represented by Tg (K) = 393.3 - 2.0 × 105/Mn for the postbaked samples (139,000 〉 Mn 〉 6500).
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230902
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  • 36
    Electronic Resource
    Electronic Resource
    Evidence for sorption-desorption phenomena during thermal cycling in highly hydrated perfluorinated membranes (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2009-2020 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Perfluorinated ionomer membranes can absorb large amounts of water. DSC experiments show the existence of exothermic or endothermic peaks for water contents larger than 8 wt % at room temperature in Nafion 1200 EW in the acid form. Changes in the number of mobile protons versus temperature have been measured by NMR spectroscopy. A desorption process with an activation energy of 6 kcal/mol is proposed during the sample cooling. Such an explanation quantitatively explains both the DSC and NMR results and is also consistent with the other results obtained from mechanical experiments, low-temperature sorption isotherms, and ESR spectroscopy.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231003
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  • 37
    Electronic Resource
    Electronic Resource
    Conformational analysis of substituted polyacetylenes (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2021-2030 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A conformational analysis of isolated chains of polymethylacetylene (PMA), polypentylacetylene (PPA), and poly(t-butylacetylene) (PTA) was carried out taking into account interactions between nonbonded atoms and torsional potentials. It was found that the trans configuration of all three polymers is more stable than the cis configuration, the difference in potential energy between the trans and the cis isomers however being very small for PTA, leading to the possibility of observing a trans→ cis isomerization in some solvents. The calculations show that the substituted polyacetylenes are not found in a planar conformation, the larger deviations from planarity being found with the bulkier substituents: PTA 〉 PPA 〉 PMA. A correlation could be established between the UV absorption limit of the samples and the minimum torsional angle of the potential-energy functions. This relation predicts that the absorption limit is shifted to long wavelengths on increasing the planarity of the molecule. Moreover, UV spectra could be calculated from the potential-energy functions, and it is shown that the potential-energy functions of other substituted polyacetylenes can be calculated from their experimental UV spectra.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231004
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  • 38
    Electronic Resource
    Electronic Resource
    Determination of the geometric structure of three substituted polyacetylenes: Polymethylacetylene, polypentylacetylene, and poly(tbutylacetylene) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2031-2041 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The geometric structure of polymethylacetylene (PMA), polypentylacetylene (PPA), and poly(t-butylacetylene) (PTA) was investigated by 1H NMR, 13C NMR, and IR spectroscopies. It was shown that both NMR techniques can be used to determine the trans isomer content of PPA and PTA, whereas the 1H NMR and IR methods can be used for PMA. A calibration curve was constructed by using the 965- and 720-cm-1 bands of the IR spectrum of PPA, and could be used in future work for the same purpose if the samples had molecular weights similar to that of the one used in this study. The isomerization kinetics of PTA was investigated and cis→ trans activation energies of 88 and 121 kJ/mol were calculated in solution and in the solid state, respectively. Heat treatment of the PMA and PPA samples always leads to a cis→ trans isomerization with a 100% trans content under extreme conditions. Moreover, a cis→ trans isomerization of PTA was induced in CCl4, CDCl3, toluene, and benzene, but a trans→ cis isomerization was induced in decalin. The reversible isomerization of PTA covered a trans isomer concentration ranging form 25 to 60%.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231005
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  • 39
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    Electronic Resource
    Spectroscopic study of α- and β-phase isotactic polypropylene and of atactic polypropylene in solution (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2043-2057 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman spectroscopy is used to investigate the conformation and packing of isotactic crystalline α-phase polypropylene compared with lower-order β-phase isotactic polypropylene and to study the solution behavior of atactic polypropylene. The high-frequency region of the spectrum is analyzed in light of a normal-mode calculation that takes into account the methyl-group vibrations. This region is sensitive to both chain conformation and packing, and because of the high intensity of the methyl and methylene high-frequency stretching modes, it can be used to probe small changes in intermolecular or intramolecular order. Differences in the thermal behavior between the two solid isotactic polypropylene samples are explained interms of packing defects which exist in the β-phase form. In the solution study, we demonstrate that, for molecules in which bands sensitive to intermolecular interactions exist, as is the case of the methyl and methylene vibrations of polypropylene, spectroscopic techniques can be used to estimate the minimum overlap concentration.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231006
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  • 40
    Electronic Resource
    Electronic Resource
    Analysis of stress-induced crystallization in high-cis-1,4-polybutadiene (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2109-2118 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Stress-induced crystallization of a crosslinked polybutadiene with a high 1,4-cis content is investigated, at room temperature. The change in the fraction of crystallinity with deformation is evaluated by two different methods. The first is based on simultaneous measurement of birefringence and stress. The second is based on calorimetric analysis. The data on crystallinity obtained by these two methods are in good agreement in the range of low deformations, while, in the range of higher deformation (λ 〉 5), the degree of crystallinity obtained by calorimetry is higher than that obtained by the optical method. Qualitative information on the crystallization was also obtained by optical analysis of the hysteresis behavior. The hysteresis data show the presence of ordering phenomena at deformations at which there seems to be no crystallinity according to both quantitative methods.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231009
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  • 41
    Electronic Resource
    Electronic Resource
    Coherent elastic scattering of a reptating chain in a melt during transient relaxation (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 833-844 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: We calculate the elastic scattering of a long chain in a polymer melt during the process of relaxation after a sudden deformation, i.e., the return to equilibrium with time, while the deformed shape is maintained. The scattering thus depends on the duration t of the relaxation, as well as on the scattering vector, and is a physical quantity characteristic of the dynamics of long chains. The reptation model of de Gennes is used as developed for deformed melts by Doi and Edwards: the chain is confined by other chains in a tube, from which disengagement by the ends is the only way of renewing its configuration. The tube diameter is taken as a parameter. We give both an analytic form and numerical evaluations. On comparison with calculations based on the Rouse model, in which the chain is assumed to be free in a viscous medium, it is seen that the experimental data (given elsewhere) should enable one to distinguish between the two models.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230501
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  • 42
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    Spectroscopic characterization of acetylene-terminated sulfone resin (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 845-859 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Fourier-transform infrared spectroscopy was used to characterize the thermal polymerization of the acetylene-terminated (AT) resin, bis[4-(3-ethynylphenoxy)phenyl]sulfone. Spectral processing techniques (including the method of factor analysis) were utilized in the analysis of the infrared data. The degree of cure was quantitatively monitored as the resin was thermally polymerized. Factor analysis indicated that only one reaction product is spectroscopically distinguishable. Further band analysis indicated the formation of predominantly trans conjugated polyene structures. No evidence for cyclotrimerization was found.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230502
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  • 43
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    Quantitative aspects of internal reflection spectroscopy: Polymer surface composition measurementThis paper was presented in part at the FACSS XI meeting, Philadelphia, Pennsylvania, 1984. (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 861-871 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The use of band-ratioing techniques in internal reflection spectroscopy (IRS) for a wide variety of polymer surface composition and orientation measurements is discussed. It is shown that quantitative data can be obtained under a wide range of experimental conditions. The effects of variations in sample contact, internal reflection element, and angle of incidence are considered in detail. The applicability and limitations of calibration procedures for the determination of surface composition under various experimental conditions are considered. The requirements for obtaining quantitative results by IRS are shown to be far more lenient than is typically assumed.
    Additional Material: 1 Ill.
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  • 44
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    Electronic Resource
    Percolation and effective-medium theories for perfluorinated ionomers and polymer composites (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 933-953 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Percolation and effective-medium theories are applied to model the transport and elastic properties of perfluorinated ionomers. The composite nature of these polymers is emphasized. The effective-medium theory is generalized to track continuously the evolution from lamellar to fibrillar morphology. The predicted dramatic difference in ion selectivity between lamellar and spherical morphology is verified quantitatively in perfluorinated ionomer blends. The limitations and potential improvements of the effective-medium theory and its relationship to percolation theory are discussed. Applications of these theories to other multiphase polymer systems are also discussed.
    Additional Material: 11 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230508
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  • 45
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    Effect of molecular weight on the refractive index increments of polystyrene, poly(ethylene glycol), poly(propylene glycol), and poly(dichlorophenylene oxide) in solution (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 925-931 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The variation of refractive index increments with molecular weight has been studied using solutions of polystyrene (2.2 × 103 〈 Mw 〈 1.8 × 106), poly(ethylene glycol) (1.0 × 103 〈 Mw 〈 2.0 × 104), and poly(dichlorophenylene oxide) (3.3 × 103 〈 Mw 〈 4.8 × 105) in toluene and poly(propylene glycol) (1.2 × 103 〈 Mw 〈 4.0 × 103) in benzene. The refractive index increments of polyglycols containing aliphatic ether moieties are negative in these solvents. However, poly(dichlorophenylene oxide) polymers, which contain aromatic ether moieties, give positive values. Linear and branched halogenated poly(phenylene oxide)s show an asymptotic approach of the refractive index increment to the same limiting value, but the approach is more rapid for the branched polymer.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230507
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    Influence of the interphase on block copolymer thermodynamics: Extension of the leary model (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1001-1029 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The Leary-Williams model for the microphase thermodynamics of triblock ABA copolymers has been modified to accommodate deviations from homogeneous random-coil configurations in the B-chain dimensions as well as in those of the A chains, and has also been extended to cover the case of diblock AB copolymers. Only planar morphology is considered, but qualitative conclusions reported herein are expected to hold for other morphologies as well. The focus is on interphase thickness ΔT, with predictions made also for separation temperature Ts and planar repeat distance D. Results are presented as systematic functions of copolymer composition (0 ≤ φA ≤ 1), total molar volume (25,000 ≤ Ṽ ≤ 4 × 106 cm3/g mol), block architecture (AB vs. ABA), temperature (298, 373 K), and for five different interphase composition profiles. In most cases, A represents a polystyrene block and B a butadiene block in these calculations. Predictions for ΔT increase with temperature and depend on architecture, profile, and Ṽ; comparisons with data are close, in the range 15-30Å. It is shown that Ts depends strongly on profile choice and φA, reaching a maximum in the φA midrange but always with φA 〉 0.5. The major parameter influencing D (at constant Ṽ) is architecture, with D(SB) ≈ 2D(SBS), and D(Ṽ) varies from D ∝ Ṽ0.75 at low Ṽ to D ∝ Ṽ0.5 at high Ṽ.
    Additional Material: 15 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230512
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    Morphological studies of liquid-crystalline cellulose derivatives. I. Liquid-crystalline characteristics of hydroxypropyl cellulose in 2-hydroxyethyl methacrylate solutions and in polymer composites prepared by bulk polymerization (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1043-1052 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The formation of liquid-crystalline structure in hydroxypropyl cellulose (HPC) in the solvent 2-hydroxyethyl methacrylate (HEMA) is described. In addition, an attempt is made to preserve the ordered structure of HPC in a composite by polymerizing the solvent. Optical evidence, including refractive index, absorption spectra, polarized-light microscopy, and x-ray diffraction, indicates that HPC-HEMA solutions exhibit the cholesteric nature of the mesophase over limited concentration and temperature ranges. The polymer composite (HPC-PHEMA) prepared from the liquid-crystalline solution by polymerization of HEMA is endowed with anisotropic organization reflecting liquid-crystalline character. Detailed morphological observations of the composite by electron microscopy show many round particles composed of parallel-stacked, disklike lamellae, and aggregate bodies developed by coalescence of neighboring particles.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230514
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  • 48
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    Time dependence of mechanical and transport properties of drawn and annealed linear polyethylene (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1217-1234 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Linear polyethylene both as drawn, or drawn and subsequently annealed with free ends, changes its length, density, crystallinity, elastic modulus, sorption, and diffusivity as the sample stands completely unrestrained at room temperature. Most of these changes occur during the first few hours. But they are important on a molecular scale since they suggest strongly that drawn, and drawn and annealed samples are far from equilibrium. As a consequence of the tendency of each mobile tie molecule in the amorphous conformation to retract and to crystallize, the specimen approaches but does not reach complete equilibrium. The transient seems to be caused by slow crystallization of tie molecules which creates crystalline bridges across the amorphous layers.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230613
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    Random-coil configurations of aromatic polyesters: Birefringence of poly(triethylene glycol terephthalate) networks in elongation (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1235-1245 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Hydroxyl-terminatd poly(triethylene glycol terephthalate) was crosslinked with an aromatic triisocyanate. Birefringence-stress-strain experiments, performed on the networks at 70°C, showed an anomalous increase in the modulus and a downturn in the birefringence-strain isotherms at high elongations. These results suggest that crystallinity is not responsible for the non-Gaussian behavior of the chains at high extension. The same kind of experiments were performed over the range 20-70°C. Values of the optical configuration parameter Δa of the order of 13.3 × 10-24 cm3 with negligible temperature coefficient were found for these networks. The quantities Δa and d In Δa/dT were calculated by means of the rotational isomeric state model. Better agreement between the theoretical and experimental values of these parameters was found for poly(triethylene glycol terephthalate) than for poly(diethylene glycol terephthalate). Since the polarities of the two chains are similar, intermolecular interactions involving terephthaloyl residues may be responsible for the discrepancies observed between theory and experiment for Δa in aromatic polyesters.
    Additional Material: 5 Ill.
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  • 50
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    Dilute-solution properties of trans-1,4-polyisoprene (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1255-1262 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Trans-1,4-polyisoprene was fractionated by both fractional precipitation and preparative gel permeation chromatography to obtain possibly sharp fractions of narrow molecular weight distribution. Selected fractions were characterized by light scattering, viscosity, and gel permeation chromatography. Necessary corrections for molecular heterogeneity were applied. Some of the characteristic relations between [η] and Mw are [η] = 1.81 × 10-4 Mw0.722 in benzene at 30°C, [η] = 1.38 × 10-4 Mw0.711 in n-hexane at 30°C, which are found to be in good agreement with literature data when corrected for molecular heterogeneity.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230616
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  • 51
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    Picosecond relaxations in hydrated polyamide-6 observed by millimeter-wave spectroscopy (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1247-1254 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Absorption measurements at millimeter-wave frequencies (50-151 GHz) are reported for dried and hydrated polyamide-6. The measurements were extended over the temperature range from liquid helium to room temperature using the oversized-cavity technique. For dried polyamide-6 (water content ≤ 0.5% w/w), a nearly linear increase with frequency and an exponential increase with temperature of the absorption coefficient is found between 50 and 300 K. This frequency and temperature dependence is described by relaxation processes in asymmetric double-well potentials. The observed relaxation times are on a picosecond time scale, thus suggesting an assignment to the NH…OC hydrogen bonds and the adjacent peptide unit (O=C—N—H). Hydration results in an increase of the absorption over the whole temperature and frequency range. This is attributed to the fact that the water of hydration is adsorbed in the neighborhood of the hydrogen bonds and changes their dynamical properties. This interpretation is supported by IR-spectroscopic measurements of the shift of amide I and amide II after hydration.
    Additional Material: 6 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230615
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    An experimental test of the relationship between creep and dynamic linear viscoelastic data (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1263-1265 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230617
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    Effects of a magnetic field applied during the curing of a polymer loaded with magnetic filler (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1267-1269 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230618
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    Dilute solutions of poly(vinyl alcohol) derived from vinyl trifluoroacetate (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1703-1712 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dilute-solution behavior of poly(vinyl alcohol) (PVAVTFA), derived from vinyl trifluoroacetate, in water-dimethylsulfoxide (DMSO) mixtures was investigated. With solvent mixtures ranging from 10 to 20 vol % DMSO, the relation between the reduced viscosity ηsp/C and the polymer concentration C was linear for polymer concentrations above 0.2 g/dL, whereas in solutions in mixed solvents of other compositions the dependence was linear for polymer concentrations above 0.1 g/dL. The relation between the intrinsic viscosity [η] obtained for aqueous solutions of PVAVTFA and the molecular weight M estimated from viscosity measurements in solutions of poly(vinyl acetate) (PVAVTFA), obtained by acetylation of PVAVTFA, was given by [η]30°Cwater = 7.34 × 10-4 M0.63. The value of [η] was greatest for the solvent mixture with 10 vol % DMSO and smallest for about 50 vol % DMSO, and Huggins constants k were smallest and greatest for these two cases, respectively. The turbidity of the solutions of low-molecular-weight PVAVTFA, was higher than that of high-molecular-weight PVAVTFA up to 30 vol % DMSO, and the reverse relation held for 40-70 vol % DMSO.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230821
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    Polydimethylsiloxane-polyurethane elastomers: Synthesis and properties of segmented copolymers and related zwitterionomers (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2319-2338 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A series of polyurethane block polymers based on hydroxybutyl-terminated polydimethyl-siloxane soft segments of molecular weight 2000 were synthesized. The hard segments consisted of 4,4′-methylenediphenylene diisocyanate (MDI) which was chain extended with either 1,4-butanediol (BD) or N-methyldiethanolamine (MDEA). The MDEA-extended materials were ionized by using 1,3-propane sultone. The weight fraction of hard segments was in the range 0.13-0.39. The morphology and properties of these polyurethane elastomers were studied by a variety of techniques. All of these short-segment block copolymers showed nearly complete phase separation. The zwitterionomer materials exhibited ionic aggregation within the hard domains. Hard-segment crystallinity or ionic aggregation did not affect the morphology. Hard-domain cohesion was found to be a more important factor than hard-domain volume fraction in determining the tensile and viscoelastic properties of these elastomers.
    Additional Material: 13 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231106
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    Polyethylene fiber formation in tubular flow. II. Discussion of precursor formation and nucleation time analysis (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2359-2368 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: This is a continuation of the preceeding paper, Part I, and presents a discussion of the nature of the precursor structure formation process observed in the flow-induced crystallization experiments described in I. A discussion of stress-induced crystallization theory as applied to these experiments is also given and a first-order analysis of crystal nucleation rates is presented. Conclusions regarding the nature of flow-induced crystallization and our current ability to quantitatively model the overall process are also presented.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231108
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    Polyethylene fiber formation in tubular flow. I. Observations of growth pattern and fiber properties (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2339-2358 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The process of seeded growth of fibrillar polyethylene crystals has been studied in a tubular flow geometry for 0.01-wt % solutions of a high-molecular-weight polyethylene in xylene. The transformation sequence has been followed visually by using polarized-light illumination in conjunction with a video camera. Data are presented to show that transformation is initiated by the formation of a concentrated, unoriented, amorphous precursor fiber within which oriented birefringent crystals subsequently grow in consequence of the stresses transmitted by the flowing solution. Time constants for the precursor formation, birefringence initiation, and completion of birefringence were measured as functions of temperature and flow rate over a range of growth conditions. Wide-angle x-ray diffraction, overall birefringence, and optical hot-stage melting data were also obtained on the grown fibers. The net result of these observations is to conclude that fibrillar crystal growth during flow is always preceded by the formation of a liquidlike phase transformation which produces the concentrated, unoriented precursor. Subsequent orientation is in consequence of stress-induced crystallization with overall fiber orientation showing an increase with solution flow rate at a fixed temperature and a decrease with temperature at a fixed flow rate. At higher temperatures and lower flow rates, birefringence develops in an oscillatory fashion, indicating a remelting process possibly due to slippage of trapped chain entanglements formed by flow. A discussion is given of the implications of these observations for the understanding of flow-induced structure development, phase transformation, and oriented crystallization; this is expanded upon in a companion paper, Part II.
    Additional Material: 10 Ill.
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    Structure of iodide ion arrays in iodinated nylon 6 and the chain orientation induced by iodine in nylon 6 filmsPresented at the XIII Congress and General Assembly of the International Union of Crystallography, August 1984, Hamburg, Federal Republic of Germany. (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2369-2376 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Two species of iodide ions (I3- and I5-) are found in iodine - nylon 6 complexes. Orientation of I5- arrays (most likely I2/I3- complex) along the polymer chain and I3- ions perpendicular to the chain axis in uniaxially drawn films and in films with planar orientation suggests that there is and intrinsic relation between the direction of iodide ion arrays and nylon 6 chains. When an unoriented film of nylon 6 in the amorphous or the α crystalline form is treated with an aqueous solution of iodine - potassium iodide, the I3- species in the resulting iodine - nylon complex lie in planes parallel to the surface of the film, and I2/I3- units are oriented normal to the surface of the film. The γ form obtained by desorbing the iodine from this complex shows considerable uniaxial rientation with the nylon chains oriented perpendicular to the plane of the film; this orientation is maintained during the γ to α transition. It is proposed that the iodine-induced orientation of the nylon 6 chains is due to the nucleating effects of the iodide ion species as the iodine diffuses unidirectionally into the film.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231109
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    Estimation of the equilibrium modulus of rubber networks by nonlinear regression analysis (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2377-2385 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A nonlinear regression analysis is presented to estimate the equilibrium modulus of relaxing rubber networks from G'(ω) or G(t) data. Various semiempirical curve-fitting equations are tested with two-function minimization algorithms.
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    Tube relaxation: A quantitative molecular model for the viscoelastic plateau of entangled polymeric mediaThis paper is dedicated to Dr. Pierre Thirion on the occasion of his retirement. (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2423-2442 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The relaxation of an entangled polymeric medium in the viscoelastic plateau is investigated theoretically by using the slip-link representation of topological constraints. In addition to the chain retraction process introduced by Daoudi and investigated theoretically by Doi, we show that two processes contribute significantly to the relaxation: The first, “equilibration across slip-links,” is a longitudinal reequilibration between parts of the chain which have been differently extended or compressed, depending on their initial orientation relatively to the strain tensor. The second, “tube relaxation,” is a mean-field representation of the loss of topological constraints on one chain due to the retraction of the others. Closed analytical expressions for the stress accounting for these three processes are derived and compared with previous theories: the relaxation should be much more progressive than previously predicted, and the terminal time for retraction is reduced significantly by tube relaxation.
    Additional Material: 4 Ill.
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    Evaluation of theories for diffusion in polymer-solvent systems (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2469-2475 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A method is proposed for examining differences in the predictive capabilities of three versions of the free-volume theory of polymer - solvent diffusion using only a small amount of diffusivity data. The utility of the method is illustrated using a limited diffusivity data set for the methanol-poly(vinyl acetate) system.
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    Temperature dependence of the crystal structures of nylon 11 (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2477-2482 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Careful examination of x-ray diffraction patterns from melt-crystallized nylon 11 films show significant discrepancies with the proposed α-form structure. These discrepancies do not disappear after the samples have been annealed. The temperature dependence of the d spacings of the two strongest peaks show further evidence that the melt-crystallized and solution-cast films (α form) possess different crystal structures. These results suggest a different crystal structure for the melt-crystallized films; this would help explain the rather low piezoelectric response of these films and also the failure to observe a rapid decrease in polarization at the transition temperature.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231206
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    Kinetics of wetting of a glass surface by molten polyethylene: An empirical approach (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2499-2504 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The spreading kinetics of molten polyethylene was studied on a flat type A glass surface. Empirical equations are known in the literature which fit the experimental data only at short times. We present a relationship between the surface free energy and the shape of the melt drop interpreted by the θ contact angle. Relating the experimental θ values obtained at different times with the surface free energy (F), we obtain curves F,t. Using isothermal data at 150°C, we could fit them with a linear relationship between In (F-F∞)/(F0-F∞) and In t/t0, where o and ∞ are related to initial and equilibrium conditions.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231208
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    The influence of morphology on the dielectric and dynamic mechanical behavior of a linear low-density polyethylene (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2483-2498 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The dielectric and viscoelastic relaxation behavior of linear low-density polyethylene has been investigated. All three usual relaxation regions occur; however, the α process is more dominant than in conventional low-density polyethylene made dielectrically active through the introduction of carbonyl groups. The observed behavior is very sensitive to orientation and morphology. There are significant differences between oriented samples (stretching or extrusion) and a single-crystal texture specimen. Effects are caused by dipolar orientation and dipolar immobilization, the relative importance of each effect varying with specimen preparation. Active dipolar groups are not carbonyls, or any common organic species, but appear to be due to chain ends having residual dipoles caused by the catalyst used in synthesis.
    Additional Material: 15 Ill.
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    Kink motion in poly(vinylidene fluoride) form I (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2505-2515 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The diffuse-streak x-ray scattering intensity from poly(vinylidene fluoride) form I, which is caused by kink bands with GTnḠ (n odd) conformation contained in the crystallite, decreases with increasing temperature, while the intensity of the 001 reflection does not change. This is attributed to the disappearance of the kink bands in the crystallite, not to partial melting of crystallites containing kink bands. The disappearance of the kink bands suggests that kink motion takes place in the crystallite. Plots of the intensity of diffuse-streak scattering, estimated from the asymmetric part of the 001 reflection, against 1/T roughly give ΔHv = -4.6 kcal/mol. This suggests that the kink band is energetically more stable than the regular structure of form I.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231209
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    An x-ray diffraction study of nonlinear polyethylene. I. Room-temperature observations (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2517-2537 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: In this investigation on samples of high- and low-density polyethylene and ethylene-vinyl acetate copolymers, crystallinities φW and crystalline densities ρcW were obtained with the aid of wide-angle x-ray scattering (WAXS) methods. From small-angle x-ray scattering (SAXS) the following characteristics were obtained either directly or by combination with the WAXS data: values, or limiting values, of the crystallinity φS; crystal densities ρcS; thicknesses of the diffuse boundary layer; number-average thicknesses of the crystalline and amorphous layers; and both number and weight averages of the long periods. It was shown that a discrepancy between φS and φW cannot be attributed to the occurrence of large amorphous regions outside the regular stacks of lamellae; the data were reconciled by assuming that the WAXS crystallinities pertain to the cores of the crystalline lamellae, whereas part of the diffuse boundary layers is comprised in the values of φS. The ρcW and ρcS data of the nonlinear samples show systematic differences, which were attributed to partial incorporation of side groups in the crystalline regions at a concentration estimated to be of the order of 20-40% of the overall concentration. With increasing side-group concentration, the thickness of the core of the crystalline lamellae was found to approach the average length of the linear chain segments between side groups. On the basis of these observations a scheme for the crystallization of nonlinear polyethylene is proposed according to which a number of side groups is encapsulated by the growing crystal. The data can be explained by assuming that all chains, offered at a crystal face where growth takes place, crystallize directly, irrespective of whether the crystallizing stem carries a side group. Further crystallization would then proceed by chain folding at both ends of the first stem, until a noncrystallizable unit is met. In this scheme, allowance is made for about half the stems in the crystals to be connected by folds; this is required in view of the “overcrowding” effect. Finally, the effect of cooling rate and molecular weight on the thicknesses of the crystalline and amorphous layers is discussed, and differences between the amorphous densities of high-and low-density polyethylene are noted.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231210
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    Stability of the γ form and the development of the α form in nylon 6 (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2549-2565 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The structure of nylon 6 fibers is analyzed by x-ray diffraction. Our results suggest that only two forms of nylon 6, α and γ, along with lattice distortion and crystallite size, are sufficient to explain the whole range of crystalline structures observed in nylon 6. The γ phase is the preferred initial form in a number of nylon 6 samples. The lattice distortion of the γ form along the chain axis varies from 0.8 to 2.4%, depending on the processing conditions. Upon annealing nylon 6 fibers, the α form is produced primarily by γ-to-α conversion in high-orientation fibers, while additional α form can also crystallize from the amorphous phase in low-orientation fibers. Finally, we show that α crystallites are favored during conditioning of poorly crystallized fibers in a humid atmosphere, and therefore fibers with α as the major crystalline form are produced upon drawing these conditioned fibers. Fibers drawn without lag time contain primarily the γ phase.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180231212
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    An x-ray diffraction study of nonlinear polyethylene. II. Small-angle scattering observations near the melting point (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2539-2548 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A method is presented for obtaining from the zeroth-order peak in small-angle x-ray scattering (SAXS) patterns the weight average of the thickness C of crystalline lamellae in polymers close to the melting point. The method fails if a first-order peak can be discerned to be superimposed on the zeroth-order peak. The method was applied, together with the one described in Part I of this series for obtaining the number average of C, to three polyethylene samples of different side-group content which were heated to temperatures close to the melting point. While heating always causes an increasing number of lamellae to melt, a linear sample also shows pronounced thickening of the remaining lamellae. This effect, however, decreases with increasing side-group content, and is virtually absent in a vinyl acetate copolymer containing 53 side groups per 1000 C atoms. A qualitative explanation for the role of the side groups in limiting the crystal thickening processes is put forward. By comparing results obtained after isothermal annealing and during isothermal crystallization from the melt it is concluded that at temperatures close to the melting point the polymers approach a final state which no longer depends on the thermal history of the sample.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231211
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  • 69
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    Crazing as quasifracture in an oriented viscoelastic medium (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2579-2597 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Crazes of different types occur in polymeric systems. Long, sparse crazes develop in less oriented molecular systems, while fine, short, dense crazes occur in highly oriented molecular systems. Different crazing mechanisms and different models may have to be studied for a better understanding of these differences. However, in this report, using one model and one theory, an analysis has been made of the differences in the geometry of craze development. By emphasizing the mechanism of molecular orientation, it is found that the basic differences are essentially attributable to the variation of the anisotropy of the material system as a result of large deformation rather than to any fundamental differences in the crazing mechanism.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231214
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  • 70
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    Light-scattering characterization of poly(ethylene terephthalate) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2567-2578 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: By using a closed-circuit filtration system, we have succeeded in clarifying poly(ethylene terephthalate) (PET) dissolved in hexafluoroisopropanol (HFIP). Such static properties as the radius of gyration Rg, the weight-average molecular weight Mw, and the second virial coefficient A2 and such dynamic properties as the translational diffusion coefficient D, or its equivalent hydrodynamic radius Rh, and the second (diffusion) virial coefficient kd were determined for several PET samples of different molecular weights by using light-scattering intensity and linewidth measurements. An empirical relation between Do (or Rh) and Mw was established: Rh = (1.77±0.15)X10-2 Mw+0.58±0.01 with Rh and Mw expressed in units of nanometers and grams per mole, respectively. The empirical exponent αD(ca. 0.58±0.01) is in good agreement with the less precisely determined intrinsic viscosity/molecular weight exponent αη (ca. 0.71±0.02). Several intensity correlation functions were measured very precisely using long accumulation times. A Laplace inversion was performed using the singular-value decomposition technique. The approximate molecular weight distribution (MWD) determined by light-scattering spectroscopy was in reasonable agreement with a completely independent determination of MWD using gel permeation chromatography (GPC). It was interesting to note, though not surprising, that GPC showed emphasis on lower-molecular-weight fractions, while light-scattering emphasized higher-molecular-weight fractions. The agreement further strengthens some complementary aspects of the two techniques.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231213
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    Epitaxial crystallization of polyethylene and paraffin on oriented polypropylene (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2623-2627 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231217
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    Studies on comblike polymers. X. Characterization of comblike polyesters by 13C NMR spectroscopy (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2611-2621 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The 13C NMR spectra of aromatic comblike polyesters obtained from 1,2-icosanediol and isomeric phthalic acids are reported and discussed. The analysis shows that the most informative spectral regions are those of the carbonyl and quaternary carbon resonances, whose peak multiplicities have been interpreted in terms of dyad and triad sequences. The results indicate that the extent of structural characterization possible for the polymers examined is dependent on the type of isomerism of the aromatic acid involved.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231216
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    Monte carlo simulations relevant to the upturns in modulus observed for natural rubber at high elongations (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2629-2632 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231218
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    Improvement in polypropylene thermal oxidative stability by annealing under an inert atmosphere (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2633-2634 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180231219
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    Estimation of the equilibrium modulus of rubber networks by nonlinear regression analysis (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 2635-2635 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180231220
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    Rebuttal to “comments on ‘some evidence against the existence of the liquid-liquid transition. III. The evaluation of the TLL event by differential scanning calorimetry’ ” (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 13-19 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: It is proposed here that readily observable viscous deformation is the common underlying phenomenon which is reflected in several kinds of evidence advanced for the existence of a liquid-liquid transition TLL. These include flow temperature Tf measurements, microscope hotstage coalescence, and differential scanning calorimetry (DSC) measurements. A DSC peak observed at Tg in high-molecular-weight bulk-polymerized poly(methyl methacrylate) is discussed in terms of the presence of conformations of low entropy.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230102
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    Comments on “some evidence against the existence of the liquid-liquid transition. III. The evaluation of the TLL event by differential scanning calorimetry”This paper is in two parts, using a common set of references. Part A was submitted in January 1983 with the same title and purpose implied by that title, but with minor modifications suggested by referees. Part B responds to the rebuttal to Part A by Chen et al. in the following paper and adds pertinent new material in response to their rebuttal. (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1-12 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The volatile-component evaporation mechanism proposed by Chen et al. to explain molecular-weight-dependent endothermic peaks found at temperatures above Tg in anionically prepared polystyrenes (PSs) on first heating in open DSC pans is inconsistent with several bodies of literature data which were overlooked, including similar data with closed DSC pans. Moreover, this mechanism appears deficient in explaining details of the dependence of the endothermic peak temperature on M̄n both below and above the entanglement molecular weight Mc, with a sharp increase in slope at Mc. The original fusion-flow mechanism of Stadnicki et al. is compatible with all other known literature data including results on thermal PS and PMMA fractions. Hot-stage microscope examination of powdered anionic PSs supports the Stadnicki mechanism from M̄n = 1900 to at least M̄n = 350,000. Addition of small amounts (ca. 1 wt %) of benzene or ethylbenzene to PS results in open-pan DSC traces without endothermic peaks but with an endothermic slope change indicating gradual loss of diluent at decreasing rate as the temperature is increased from below Tg up through the TLL region.
    Additional Material: 4 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230101
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    Carbon-13 NMR relaxation and transitions in polymers (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 367-385 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: High-resolution proton-decoupled carbon-13 nuclear magnetic resonance relaxation parameters have been obtained as a function of temperature for a set of completely amorphous polymers, semicrystalline polymers, and a series of ethylene-vinyl acetate copolymers. With these samples the nature of the glass temperature, other postulated amorphous transitions, and the β transition were investigated. For the completely amorphous polymers, the average correlation times depend on temperature according to the Williams-Landel-Ferry relation. Spectral collapse occurs at temperatures whose ratio to Tg is in the range 1.2-1.4 and corresponds to a correlation time of about 10-7s. The loss of resolvable spectra is demonstrated to be a consequence of experimental methods and is not due to the occurrence of another amorphous transition. Both the methylene and methine carbons can be resolved for the ethylenevinyl acetate copolymers. Although the correlation time for the methylene carbon is continuous and resolvable through the β transition region, the methine branch-point resonance is lost. The implication of these results to the molecular nature of the β transition is discussed.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230211
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    Phase transitions in mesophase macromolecules. V. Transitions in poly(oxy-1,4-phenylene carbonyl-co-oxy-2,6-naphthaloyl) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 521-535 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The copolymer system HBA (4-hydroxybenzoic acid) and HNA (2,6-hydroxyhaphthoic acid) has been studied mainly by means of differential scanning calorimetry. Heat capacities for the two homopolymers and three copolymers are reported from 175 to 650 K. The heat capacities are additive with composition. The whole copolymer system represents an example of a mesophase intermediate between the liquid-crystalline and the condis-crystalline state with a small amount of crystallinity. The disordering transitions (520-620 K) have a eutecticlike phase diagram. The transitions to the isotropic states occur above the decomposition temperatures (600-700 K). The glass transitions (377-434 K) show normal changes in heat capacity (31-34 J/K mol), but are broadened to as much as 200 K.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230309
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  • 80
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    Rheo-optical studies of concentrated polystyrene solutions subjected to transient simple shear flow (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 575-589 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Concentrated polystyrene solutions were investigated on the inception and cessation of simple shear flow by means of the technique of two-color flow birefringence. Both monodisperse solutions of various molecular weights and bimodal mixtures were studied. The molecular weight affected both the amount of overshoot in the birefringence and the response time on the inception of shear flow. Large overshoots in birefringence, up to 250%, and undershoot in the orientation angle were observed. The shear stress and the first normal stress difference were calculated by using the stress-optical rule. The amount of strain at the peaks in the stress growth curves are presented along with the steady-state viscosity and primary normal stress coefficient. The experimental results are compared qualitatively with theoretical predictions of various molecular models.
    Additional Material: 16 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230313
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    Macromolecular pair correlation functions from fluorescence depolarization experiments (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 591-599 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Depolarization of fluorescence resulting from the transport of electronic excitations in chromophore-containing polymers is investigated as a technique for detecting deviations from ideal-chain statistics. An approximate expression for the fluorescence anisotropy that depends only on the pair correlation function of chromophore labels is presented. This approximation is shown to be accurate for particular cases of long-range correlations, short-range correlations, and no correlations among chromophore positions. The formalism allows fluorescence depolarization experiments to be used as a probe of macromolecular pair correlation functions.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230314
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    Low-frequency excitations in amorphous poly(vinyl acetate) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 609-614 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Raman-active modes have been detected in amorphous poly(vinyl acetate) in the frequency region 20-160 cm-1. The low-frequency spectrum appears as a broad band for all three molecular weights examined. Spectra were recorded at two temperatures, 293 and 77 K, and found to show similar characteristics at both temperatures. The presence in solid amorphous polymers of broad structureless bands in general and their significance are discussed.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230401
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    Crystallization in oriented poly(ethylene terephthalate) fibers. I. Fundamental aspects (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 653-674 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The nature of crystallization- and mobility-induced changes during annealing of melt-spun poly(ethylene terephthalate) precursor fibers of a range of orientations has been examined. The kinetics of crystallization and the accompanying orientational changes have been studied under conditions of constant, low tensile stress, with the accompanying dimensional changes and under a constraint against shrinkage in length, with the stress developed being monitored. The effects of precursor orientation and externally imposed constraints on the course of the fundamental crystallization and orientational relaxation processes are revealed. Oriented crystallization has been shown to have a significant effect on the stress developed and on the dimensions of oriented precursor fibers, with a strong tendency to spontaneously extend as a consequence of the reorientation of crystallizing segments predominantly along the preferred fiber direction. The sequence in which crystallization and major orientational relaxation, if any, occur is found to have a profound effect on the structure and thus the deformability of oriented fibers after annealing above the glass transition temperature.
    Additional Material: 20 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230404
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    Relaxation of chemical potential and a generalized diffusion equation (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 675-682 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The effect of slow structural relaxation in a solvent of high viscosity on the chemical potential driving the diffusion of penetrant molecules is described by a generalized diffusion equation with a memory term. The linearized version of this equation is solved for some special cases, and the correlation function of concentration fluctuations in thermodynamic equilibrium is calculated. As a result of the memory term, for very slow relaxation two different stages of the diffusion process can be distinguished.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230405
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    Energy absorption in polymer crazing (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 683-693 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The total energy absorbed by a craze during its development in creep is analyzed and calculated on the basis of a time-dependent theory of crazing. Experimental measurements of the craze length have been utilized in the energy calculations. For polystyrene the initial energy absorption in the craze region is found to be several hundred times that in the uncrazed medium. This ratio decreases sharply in a short period of time to about 50 to 1 and less and remains low afterward. For polycarbonate, somewhat similar behavior has been found. The initial strain energy absorption by crazing is about 200 times that in the uncrazed region. The energy ratio reduces rapidly to about 55 to 1 and tends to level off thereafter. However, in general, the amount of strain energy absorbed does increase as a function of time, as it should.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230406
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    Bead-spring model for adsorbed polymer chains in shear flow: Hydrodynamic interaction (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 695-707 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: We consider the hydrodynamic interaction between two absorbed polymer chains in a simple shear flow, each modeled by a bead connected to the wall by a linear spring. It is concluded that hydrodynamic interaction between the beads or between the beads and the wall cannot be responsible for the experimentally observed increase in hydrodynamic thickness.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230407
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  • 87
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    Rheological and DSC changes in poly(vinyl alcohol) gels induced by immersion in water (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1803-1811 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Poly(vinyl alcohol) (PVA) gels were prepared by freezing and thawing aqueous solutions at temperatures from -20 to 15°C. The temperature was varied periodically by use of a computer. The endothermic DSC peak was observed for the PVA gels at about 60°C for five specimens of different degrees of saponification (DS). Another endothermic peak was also observed in the range 67-80°C, and this peak shifted to higher temperature with increasing DS. These endothermic peaks shifted to lower temperature on immersion of the PVA gels in water. The dynamic Young's modulus E′ at room temperature was also decreased by immersion of PVA gels in water; E′ decreased monotonically with increasing temperature for PVA gels without immersion in water, while it increased up to a certain temperature and then decreased with increasing temperature for PVA gels in water. The X-ray diffraction showed a characteristic crystalline pattern for PVA gels of higher DS, and this peak was intensified by stretching the gel.
    Additional Material: 10 Ill.
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    URL: http://dx.doi.org/10.1002/pol.1985.180230906
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    Study of spin-lattice relaxation and local motion in dissolved poly[2,2-propanediylbis(3,5-dimethyl-4, hydroxyphenyl)carbonate] (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1793-1802 
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    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Proton and carbon-13 spin-lattice relaxation times are reported for 10-wt % solutions of tetramethyl bisphenol-A polycarbonate. The relaxation times for both nuclei were measured at two Larmor frequencies and as a function of temperature. These relaxation times are interpreted in terms of three motions: segmental motion, restricted rotational diffusion, and backbone methyl-group rotation. The Hall-Helfand correlation function is used to describe the segmental motion. Internal rotation is described by the usual Woessner approach and restricted anisotropic rotational diffusion by the Gronski approach. As demonstrated by its higher activation energy, correlated segmental motion appears to be slower than the unsubstituted polycarbonate of BPA. In addition, the single-transition processes seem to be still less important than correlated backbone transitions. Phenylene-group rotation is described in terms of restricted rotational diffusion instead of complete anisotropic rotation. The time scale for backbone methyl-group rotation is comparable to that in BPA, a fact indicative of weaker cooperativity between this motion and the other motions. Rotation of the methyl group attached to the phenylene ring is too fast to significantly contribute to relaxation except by partially averaging the dipole-dipole interactions. The higher activation energies for segmental motion observed in solution for this methyl-substituted polycarbonate relative to the unsubstituted polycarbonate parallel a significant increase in the glass transition temperature observed for the substituted material. The restricted pheylene-group rotation in solution is also parallelled by a large upward shift of the low-temperature loss peak in the glassy polymer.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230905
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  • 89
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    The role of molecular diffusion in the adhesion of EPDM and EPR elastomers (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1823-1830 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Adhesion of lightly crosslinked sheets of EPDM (ethylene-propylene-diene terpolymer) to themselves and to a Mylar substrate has been investigated over wide ranges of peel rate and test temperature. The effect of incorporating ethylene-propylene copolymer (EPR) before crosslinking, to yield a loose macromolecular network containing dissolved linear EPR macromolecules, was also studied. The self-adhesion of these materials was found to be much greater than their adhesion to Mylar, over a wide range of effective peel rates. This is attributed to interdiffusion of EPR and EPDM molecular strands. At extremely low peel rates the enhancement of adhesion was smaller, probably because of back-diffusion, and at high rates, the strength of adhesion became high in all cases. These results are compared to those obtained previously for polyisobutylene-co- isoprene networks containing linear polyisobutylene molecules. The enhancement of self-adhesion at intermediate rates of peel was considerably greater for the EPDM-based materials, probably because of a lower degree of crosslinking and a greater tendency to form molecular entanglements.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230908
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  • 90
    Electronic Resource
    Electronic Resource
    Differential sorption in viscoelastic fluids (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1831-1855 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The diffusion of organic solvents in concentrated polymer solutions often deviates from the predictions of Fick's second law, especially when the solution is in the glassy state; such behavior is called anomalous or non-Fickian. This paper analyzes the one-dimensional sorption of a solvent into a concentrated polymer solution under a small driving force. The treatment includes the effect of an entanglement network on the process as postulated by Thomas and Windle. The deformation of the entanglement network during sorption creates a normal stress on the solvent equivalent to an osmotic pressure. Including the osmotic pressure gradient in the driving force for solvent diffusion leads to a linear, third-order partial differential equation for solvent concentration distributions. By evaluating the physical constants in the theory for the system methyl acetate/poly(methyl methacrylate) at 30°C the treatment is shown to predict the anomalous characteristics found experimentally.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230909
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  • 91
    Electronic Resource
    Electronic Resource
    A SAXS study of a single crack and craze in plasticized polystyrene (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1857-1867 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Small-angle x-ray scattering (SAXS) was used to study the structure along a single craze that had broken down to form a crack along part of its length. This study was made possible by use of radiation from the synchrotron source CHESS which is sufficiently intense to permit examination of just a single craze. The total scattering from the craze was in excellent agreement with that expected from a knowledge of its dimensions and fibril volume fraction and width. This fact adds confidence to the interpretation of the scattering pattern of the craze as part diffraction, part reflection, and demonstrates that SAXS is a technique that may be used to measure craze volume within a sample. The craze was shown to grow in width by surface drawing with a constant structure, and then the fibrils broke to form a crack. The broken fibrils contracted and their diameters increased but they appeared to stay parallel with a constant fibril-axis radial distribution function.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230910
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  • 92
    Electronic Resource
    Electronic Resource
    Far-infrared studies of microphase separation in sulfonated ionomers (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1869-1881 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Far-infrared spectra of a series of un-neutralized and neutralized lightly sulfonated polystyrenes with varying sulfonation levels have been investigated to seek spectroscopic evidence for microphase separation known to control the physical properties of these polymers. Broad, strong absorbance bands, not found in the spectrum of unmodified polystyrene, are observed in the spectra of the sulfonated analogs. The effects on the far-infrared spectra both of sulfonation level and of the mass and charge of the neutralizing cation are discussed in terms of cation motion and the formation of ion-rich domains.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230911
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  • 93
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    Electronic Resource
    Small-angle scattering analysis of hard-microdomain structure and microphase mixing in polyurethane elastomers (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1883-1913 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The microdomain structure of a series of segmented polyurethane block copolymers is characterized by small-angle x-ray and neutron scattering analyses. The materials contain hard segments formed from 4,4′- diphenylmethane diisocyanate (MDI) and butanediol (BD), and range in hard-segment content from 20 to 80% by weight. The results provide evidence for a transition from discrete to continuous hard-microdomain morphology as the hard-segment content is increased above ca. 50%. The measured concentration dependences of the interdomain spacing, specific interfacial area, diffuse microphase boundary thickness, and scattering invariants are used to examine the validity of present models for hard-microdomain structure. The observed behavior corresponds well with the general predictions of a lamellar model wherein partially coiled hard-segment sequence configurations are allowed. The thickness of the hard microdomains extracted from the model corresponds to approximately four hard-segment repeat units. Scattering invariant calculations are used together with determinations of the soft-microphase glass transition temperatures to examine possible models for microdomain mixing. These calculations suggest that both the hard and soft microphases are phase mixed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230912
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  • 94
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    The structure of MDI/BDO-based polyurethanes: Diffraction studies on model compounds and oriented thin films (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1915-1932 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polyurethanes based on MDI/BDO are known to crystallize in three distinct forms. Two of these crystal structures, type II and type III, have been characterized by electron and x-ray diffraction experiments on model compounds and oriented thin films of a 77% hard-segment polyurethane elastomer. The model compounds were of the form BDO(MDI/BDO)n with n = 1, 2, 3. Results from the model compounds indicate that the MDI/BDO repeat crystallizes in the type-II structure, which has a contracted conformation with a monomer repeat length of 1.70 nm. MDI/BDO-based polyurethanes also exhibit the type-II structure under quiescent crystallization conditions. Studies of oriented thin films of an MDI/BDO-based polyurethane indicate that a change in crystal form occurs on stretching to the fully extended monomer conformation. This crystal form is termed type III and has a monomer repeat length of 1.92 nm.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230913
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  • 95
    Electronic Resource
    Electronic Resource
    Extraction and sorption studies using linear polymer chains and model networks (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1933-1940 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Model networks have been prepared by tetrafunctionally endlinking linear polydimethylsiloxane (PDMS) chains having molecular weights Mn in the range 2000-15,000 g mole-1. The first series of networks were prepared from mixtures containing known amounts of unreactive linear PDMS chains with molecular weights Md between 1000 and 16,000 g mole-1. Rates of extraction were used to estimate diffusion coefficients; as expected, they were found to increase with increase in molecular weight Mc = Mn between crosslinks, but to decrease with increase in Md. The ease with which all of such a diluent could be removed showed the same dependence on Mc and Md. A second series of networks was prepared from the same reactive PDMS chains without diluents. Sorption and extraction studies using the same diluents were then carried out. The diffusion coefficients for sorption were found to be in the range (1.7-15.0) × 10-12 m2 s-1 and depended on both Mc and Md. The amount of diluent absorbed at equilibrium was between 10 and 70%, which is in good agreement with predictions from the Flory equation for dilation in networks, with account of constraints on crosslink fluctuations.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230914
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  • 96
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    Electronic Resource
    Phase separation phenomena in solutions of poly(2,6-dimethyl-1,4-phenyleneoxide) in mixtures of trichloroethylene, 1-octanol, and methanol: Relationship to membrane formationA part of this work was presented at the First Europe-Japan Congress on Membranes and Membrane Processes, Stresa, Italy, June 18-22, 1984. (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1941-1955 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The phase boundaries in the quaternary system consisting of the polymer poly(2,6-dimethyl-1,4-phenyleneoxide) (PPOPPO is a registered trademark of the General Electric Company.), the solvent trichloroethylene (TCE), and the nonsolvents 1-octanol (OcOH) and methanol (MeOH) are determined. The kinetics of crystallization are investigated by pulse-induced critical scattering. The formation and properties of PPO membranes are discussed in relation to the phase separation phenomena.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230915
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  • 97
    Electronic Resource
    Electronic Resource
    Short-branch formation via the roedel mechanism in copolymers of ethylene and vinyl acetate (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1957-1965 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: A realistic rotational isomeric state model has been used to estimate the relative probabilities of the formation of various types of short branches in ethylene-vinyl acetate copolymers that are rich in ethylene. Butyl is predicted to be the most common short branch in all of the copolymers examined, although it is less common in the copolymers than in low-density polyethylene. The major factor responsible for the suppression of the R04 backbiting intrachain radical transfer is the increased preference for trans states at the mainchain bonds flanking the attachment site for an isolated acetoxy side chain.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230916
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  • 98
    Electronic Resource
    Electronic Resource
    The local structure of blends of polystyrene and poly(2,6-dimethylphenylene oxide) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1967-1974 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Polystyrene (PS) and poly(2,6-dimethylphenylene oxide) (PPO) are miscible over the complete composition range. The addition of 30-40% PPO to PS changes the mechanical behavior of the material from brittle to tough and ductile. The x-ray scattering curves from unoriented and oriented samples of PS and of PPO are compared with those from a 50/50 blend. The introduction of PPO into PS disrupts microsegregation of phenyl groups into stacks which are a feature of the pure polymer and which may be responsible for formation of sharp shear bands and brittle behavior of PS. The local structure of the blend is significantly different from both PS and PPO.
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180230917
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  • 99
    Electronic Resource
    Electronic Resource
    Dynamic behavior of flexible polymers at a solid/liquid interface (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1997-2008 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The mean time spent by a macromolecule at a solid/liquid interface is analyzed in the region of adsorption saturation. The method consists of carrying out preliminary adsorption with radioactively labeled high-molecular-weight polyacrylamide and subsequently exposing the surface to a solution of unlabeled polyacrylamide. It was found that, apart from a small fraction of polymers “loosely” attached, the exchange between labeled and unlabeled polymers takes place at the interface at a very slow rate. Furthermore, desorption of surface molecules occurs only in the presence of a solution, and then the rate of desorption increases proportionally to the number of molecules in the solution. A mechanism based on a bimolecular chemical exchange process is proposed.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180231002
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  • 100
    Electronic Resource
    Electronic Resource
    Miscibility and deformation behavior in some thermoplastic polymer blends containing poly(styrene-co-acrylonitrile) (1985)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Physics Edition 23 (1985), S. 1975-1995 
    Details
    ISSN: 0098-1273
    Keywords: Physics ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Miscibility in blends of poly(styrene-co-acrylonitrile) (PSAN) with several other polymeric components has been investigated over a range of compositions by means of thermal analysis and transmission electron microscopy. Systems in vestigated were (i) PSAN/polycarbonate (PC), (ii) PSAN/styrene-maleic anhydride-methyl methacrylate terpolymer (S/MA/MM), (iii) PSAN/polynorbornene nitrile (PNN), and (iv) PSAN//S/MA/MM//PC. PSAN/PC was demonstrated to be partially miscible in all proportions over the PSAN copolymer composition range 23-70 wt % AN, while the miscibility or lack thereof of PSAN//S/MA/MM depended on the relative AN and MA contents of the PSAN and S/MA/MM, respectively. In contrast, PSAN/PNN was found to be immiscible in all proporations, while the system PSAN//S/MA/MM//PC was shown to be partially miscible. Deformation studies performed on rubber-modified versions of these blends defined deformation mode and microstructural deformation behavior. Dual extensometer tensile testing yielded relative contributions of crazing and of plastic flow, which correlated both with blend composition and with toughness. TEM observations of deformed specimens indicated a deformation process in the multiphase matrix blends consisting of craze initiation and propagation in the rubber-containing phase, craze arresting in the ductile second matrix phase, and coordinated extensive deformation of the matrix phases and of the rubber particles, where the ability to support the latter coordinated forms of deformation were observed to increase with increasing proportion of plastically deforming phase.
    Additional Material: 23 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1985.180231001
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