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  • 1985-1989  (62)
  • Polymer and Materials Science  (50)
  • Life and Medical Sciences  (12)
  • 1
    Electronic Resource
    Electronic Resource
    Investigation on the microstructure of poly(cyclohexyl α-chloroacrylate)s using 500 MHz 1H and 25 MHz 13C NMR (1986)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 187 (1986), S. 375-381 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: The tacticity of poly(cyclohexyl α-chloroacrylate) (PCCA) was studied by 500 MHz 1H and 25 MHz 13C NMR spectroscopy. The influence of the polymer configuration was observed at three different carbon resonances: The backbone methylene carbon, the carbonyl carbon and the quaternary carbon. Tetrad tacticities of PCCA measured from the resonance of the backbone methylene carbon were in good agreement with tetrad values obtained by 1H NMR. The polymer obtained was syndiotactic rich and obeyed Bernoullian statistics in its tacticity distribution.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1986.021870217
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  • 2
    Electronic Resource
    Electronic Resource
    Properties of polyacetylene obtained with (η-Cp)2Ti(PMe3)2 (1989)
    New York : Wiley-Blackwell
    Die Makromolekulare Chemie 190 (1989), S. 1309-1317 
    Details
    ISSN: 0025-116X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Notes: Acetylene was polymerized by (η-Cp)2Ti(PMe3)2 at room temperature to give predominantly trans-polyacetylene. All properties are within the ranges reported for polyacetylene produced with Ti(OBu)4/AlEt3 as catalyst.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/macp.1989.021900611
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    Paper (German National Licenses)
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  • 3
    Electronic Resource
    Electronic Resource
    Transport and related properties of paint films. II. Dynamic mechanical properties and humidity effects (1985)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 30 (1985), S. 111-133 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: A systematic four-stage investigation of eight unpigmented coating formulations, including three vinyl, two polyurethanes, and three epoxy systems was done to provide baseline structural information upon which an improved understanding and an optimization of protective coatings can be founded. First, the results from dynamic mechanical measurements are provided and discussed for the base polymer component in each coating system. Second, the effects of humidity on the dynamic mechanical properties of these base polymers were determined at room temperature. The extent of property degradation was monitored by calculating the Tg depression with increased humidity, assuming a temperature-humidity superposition. The extent of degradation, as monitored by the Tg, was found to correlate directly with the level of hydrogen bonding in these coatings. Third, the influence of typical coating additives (a TCP plasticizer and a rosin hardener) on the properties of two of the vinyl coating systems was investigated. In the final stage, the synergistic effects of absorbed moisture and these additives on the coatings properties were investigated at room temperature. Increases in the concentration of these additives was found to magnify the degradation effect of increased humidity. This magnified degradation has been assigned to increased water absorption with increases in the concentration of either of these additives.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1985.070300109
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  • 4
    Electronic Resource
    Electronic Resource
    Dielectric studies of the cure of epoxy matrix systems (1986)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 31 (1986), S. 1155-1167 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Dielectric spectroscopy was used to monitor the curing process of two epoxy resin systems. The basic system (system I) consisted of DGEBA (a difunctional epoxy) and a polyamide in a 50-phr mixture. In addition, a comparative analysis was performed on a high-performance resin system (system II) used primarily in unidirectional composite applications. This system contained TGDDM (a tetrafunctional epoxy) and DDS (a tetrafunctional amine) in a 25-phr mixture. The dielectric data were obtained using a simple yet functional sample cell electrode designed and constructed in the laboratory. For system I, isothermal dielectric data were used to determine apparent activation energies for the temperature range from 22 to 70°C. The data showed that the activation energy was a function of temperature and increased as the temperature of the cure increased. This indicated that the reaction mechanism was also a function of temperature. For system II, data were collected between 140 and 190°C and an overall activation energy for that temperature range was determined. The overall activation energies for both systems, calculated using dielectric spectroscopy, compared favorably to those obtained using differential scanning calorimetry. Also, using a wider frequency range (240 Hz to 2 MHz), Argand diagrams were constructed and modeled with the Cole-Cole empirical equation for systems with a distribution of relaxation times. This justified the calculation of average relaxation times, which could then be related to the bulk physical properties of the polymer, such as viscosity. Modified Argand diagrams, where ε″ is plotted against ε′ at one frequency as a function of time, were also constructed, which aided in the understanding of the curing processes for these thermosetting systems.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1986.070310501
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  • 5
    Electronic Resource
    Electronic Resource
    Structure-property relationships in thermoplastic elastomers. IV. Dynamic mechanical relaxations in polydioxolane, polybutyltrioxocane, and poly(propylene oxide) polyurethanes (1988)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 36 (1988), S. 1387-1400 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Dynamic mechanical measurements had been made on polyurethanes of a range of hard segment content (HSC) obtained from α,ω-dihydroxy derivatives of polydioxolane, polybutyltrioxocane, and poly(propylene oxide) of 2000-12,000 MW coupled with MDI and TDI with hydroxyethyl phthalamide chain extenders. N-methylated chain extender was used to investigate the effect of hydrogen bonding. A broad γ transition was observed between -100 and -115°C attributable to the local motion of methylene sequences with a distribution of relaxations. The β-transition between -55 and -72°C is influenced by the degree of hydration; the α-transition occurs at nearly the same temperatures for all the TPEs, independent of HSC and thermal history. The magnitude of the loss tangent peak is nearly proportional to the soft segment content; the peak corresponds to the glass transition. An α-transition at higher temperature is sensitive to the structure of soft segment, HSC, and thermal history. It is probably associated with the melting of some weakly ordered regions in the soft domain. The hard domain counterpart was observed at the next higher temperature as the ∊-relaxation. The final large loss of storage modulus occurs at temperatures much below the melting transition.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1988.070360610
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  • 6
    Electronic Resource
    Electronic Resource
    Acid-catalyzed degradation of poly(2-butyl-1, 3, 6-trioxocane) (1986)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 24 (1986), S. 2903-2917 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acid-catalyzed degradation of poly(2-butyl-1,3,6-trioxocane) (1) has been studied. With ethyl tosylate as the catalyst, the cyclic monomer 2 was the major product. The minor products are cis and trans isomers of C3H7CH=CH—OCH2CH2OCH2CH2OH, and three stereoisomers of C3H7CH=CH—OCH2CH2OCH2CH2O—CH=CH—C3H7 elucidated by 1H and 13C NMR, IR, electron impact and chemical ionization MS, and in the case of 2 also by comparison with an authentic sample. With 98% H2SO4 as the catalyst 2 is only a minor product. The major products are diethylene glycol, valeraldehyde, and 1,4-dioxane with some 2-butyl-1,3-dioxolane. Capillary GC/mass spectrometry led to identification of the following less abundant products: tri-n-propylbenzene, α,β-unsaturated aldehydes, and cyclic dimer. The products of H2SO4-catalyzed decomposition of polymer were also obtained by heating monomer 2 with H2SO4. A detailed mechanism for the formation of the eight-member ring 2 in the decomposition is proposed which involves unzipping proceeds via open carbocation intermediates. According to the principle of microscopic reversibility, the same open carbocation is the propagating species in the polymerization of 2 under similar conditions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1986.080241118
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  • 7
    Electronic Resource
    Electronic Resource
    Poly(arylsulfone imide) as E-beam resist: Synthesis and radiolysis (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 915-928 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Aromatic diamines containing —SO2— and —S— moieties have been used to prepare soluble polyimides with ditrifluoromethyl methane bis(phthalic anhydride) (F-series polyimides) and polyamic acid with pyromellitic dianhydride (P-series). Gamma radiolysis gave G(S) values for scission between 1 to 2 with no crosslinking. Significant weight loss occurred with radiolysis is attributable to efficient —SO2— bond scission for the F-series polyimides, as well as imidization in the cases of P-series polyamic acids.
    Additional Material: 10 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270316
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  • 8
    Electronic Resource
    Electronic Resource
    Superactive and stereospecific catalysts. III. Definitive identification of active sites by electron paramagnetic resonance (1989)
    Bognor Regis [u.a.] : Wiley-Blackwell
    Journal of Polymer Science Part A: Polymer Chemistry 27 (1989), S. 897-913 
    Details
    ISSN: 0887-624X
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Superactive Ziegler-Natta catalysts have been prepared from a soluble MgCl2·2-ethyl hexanol adduct in the presence of organic esters through reactions with TiCl4 and activated with AlEt3/phenyltriethoxy-silane. Electron paramagnetic spectra (EPR) were used to elucidate the nature and amount of those Ti+3 ions not bridged to another Ti+3 ion; the chlorine bridged Ti+3 ions are EPR silent. The EPR spectra were attributed to two rhombic Ti+3 sites with principal values for the g-tensors (1.967, 1.949, 1.915; and 1.979, 1.935, 1.887). The total amount of the EPR species, obtained by double integration of the EPR spectra, is in close agreement with the concentration of isospecific catalytic sites determined by radiotagging. This suggests that the nonspecific sites are EPR silent. When o-phthalic ester was present during the catalyst synthesis, there appears an EPR signal at the free electron g-value. This signal was attributed to a Ti+3 phthalate species with resonance stabilization and spin delocalization; it is absent in the catalysts made in the presence of monoesters such as ethyl benzoate. The effects of monomer, O2, H2O, and I2 on the EPR spectra were investigated. The changes in the EPR spectral intensity and the total Ti+3 ions, the latter determined by redox titrations during a polymerization or catalyst aging, are described. The results were extensively compared with those observed for supported Ziegler-Natta catalyst prepared with crystalline MgCl2.
    Additional Material: 14 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pola.1989.080270315
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  • 9
    Electronic Resource
    Electronic Resource
    Thermo-oxidative decomposition of poly (ether ether ketone) (1986)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 24 (1986), S. 641-644 
    Details
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1986.140241204
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  • 10
    Electronic Resource
    Electronic Resource
    Motion of junction point in network systems by 31P-NMR lineshapes and relaxation (1988)
    New York : Wiley-Blackwell
    Journal of Polymer Science: Polymer Letters Edition 26 (1988), S. 191-194 
    Details
    ISSN: 0887-6258
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/pol.1988.140260404
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