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  • 1
    Electronic Resource
    Electronic Resource
    Characterization of Reacting Polymer Systems by Temperature-Modulated Differential Scanning Calorimetry (1998)
    Springer
    Journal of thermal analysis and calorimetry 54 (1998), S. 585-604 
    Details
    ISSN: 1572-8943
    Keywords: epoxy resin ; inorganic polymer glass ; reaction-induced phase separation ; reaction mechanism ; TMDSC ; unsaturated polyester resin
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The benefits of temperature-modulated differential scanning calorimetry to characterize reacting polymers are illustrated for different experimental systems. The effects of combined isothermal and non-isothermal cure paths on (de)vitrification, mobility-restricted reactions, and relaxation during vitrification are discussed for anhydride- and amine-cured epoxies. The simultaneous measurement of heat capacity, heat flow, and heat flow phase provides an excellent tool for mechanistic interpretations. The influence of the metakaolinite particle size on the production of inorganic silicate-metakaolinite polymer glasses is treated as an example. These principles are further illustrated for primary and secondary amine-epoxy step growth reactions, and for styrene-cured unsaturated polyester chain growth reactions with ‘gel effect’. Finally, the effects of isothermal cure and temperature on reaction-induced phase separation in a polyethersulfone modified epoxy-amine system are highlighted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010150711172
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  • 2
    Electronic Resource
    Electronic Resource
    TMDSC and Dynamic Rheometry, Gelation, Vitrification and Autoacceleration in the Cure of an Unsaturated Polyester Resin (2000)
    Springer
    Journal of thermal analysis and calorimetry 59 (2000), S. 305-318 
    Details
    ISSN: 1572-8943
    Keywords: autoacceleration ; dynamic rheometry ; gelation ; gel effect ; TMDSC ; unsaturated polyester resin ; vitrification
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The free radical cross-linking copolymerization of an unsaturated polyester resin with styrene is studied in isothermal conditions using temperature modulated differential scanning calorimetry (TMDSC) and dynamic rheometry. The dynamic rheometry measurements show that gelation occurs at a conversion below 5%, while TMDSC measurements show that an important autoacceleration starts near 60% conversion, giving rise to a maximum cure rate closely before the (partial) vitrification of the system near 80%. This indicates that the autoacceleration is not due to the sharp increase in bulk viscosity at gelation, but rather to a change in molecular mobilities at higher conversion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010112718501
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  • 3
    Electronic Resource
    Electronic Resource
    Influence of the Degree of Dehydroxylation of Kaolinite on the Properties of Aluminosilicate Glasses (2000)
    Springer
    Journal of thermal analysis and calorimetry 62 (2000), S. 417-427 
    Details
    ISSN: 1572-8943
    Keywords: differential scanning calorimetry ; FTIR ; inorganic polymer glasses ; kaolinite ; metakaolinite ; TG
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The degree of dehydroxylation of kaolinite, DTG and DIR, respectively, is characterized by thermogravimetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR). The relation between DTG and DIR based on the infrared absorptions at 3600–3700, 915, 810, and 540 cm−1 is established. Three regions can clearly be distinguished: the dehydroxylation region (DTG〈0.9), the metakaolinite region (0.9〈DTG〈1) and the ‘spinel’ region(DTG=1). The effect of the degree of dehydroxylation of kaolinite on the amount of reactive material is measured by the reaction enthalpy, ΔH, of the low-temperature reaction of the dehydroxylated kaolinite with a potassium silicate solution using differential scanning calorimetry (DSC). |ΔH| increases almost linearly with DTG in the dehydroxylation region. In the metakaolinite region, ΔH and thus the amount of reactive material, becomes constant. |ΔH| is sharply decreasing when metakaolinite transforms into other phases in the ‘spinel’ region. No significant differences in the reactivity of the dehydroxylates is detected with DSC. According to FTIR, the use of partially dehydroxylated kaolinite is not influencing the molecular structure of the low-temperature synthesized aluminosilicates, but residual kaolinite is retrieved as an additive.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1010138130395
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  • 4
    Electronic Resource
    Electronic Resource
    Low-temperature synthesized aluminosilicate glasses: Part III Influence of the composition of the silicate solution on production, structure and properties (1997)
    Springer
    Journal of materials science 32 (1997), S. 2237-2247 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The low-temperature reaction between an aqueous sodium or potassium silicate solution and metakaolinite yields a solid aluminosilicate. The influence of the molar ratios H2O/R2O (between 6.6 and 21.0) and SiO2/R2O (between 0.0 and 2.3) of the silicate solution (R=Na or K) on the aluminosilicate's production, on the reaction stoichiometry and on the aluminosilicate's molecular structure is studied with differential scanning calorimetry, 27Al and 29Si magic angle spinning nuclear magnetic resonance (MAS NMR), cross-polarization MAS NMR, Fourier transform infrared spectroscopy and X-ray diffractometry. The reaction stoichiometry is determined by a one to one ratio for R/Al. H2O/R2O has no influence on the molecular structure of the aluminosilicate. Aluminium in the aluminosilicate is four-fold coordinated for the whole range of silicate solutions investigated. Moreover, Si and Al are homogeneously distributed and the ratio Al/Si in the aluminosilicate is the same as in the reaction mixture if the stoichiometric one-to-one ratio for R/Al is used. If SiO2/R2O in the Na-silicate solution is equal to or higher than 0.8, the low-temperature reaction yields an amorphous aluminosilicate or “inorganic polymer glass”. For smaller values of SiO2/R2O the Na-aluminosilicates are partially crystalline. Thermomechanical analysis and dynamic mechanical analysis indicate that a variation in the composition of the amorphous aluminosilicates can shift the glass transition over a few hundreds of degrees, with a minimum value of 650°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1018563914630
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  • 5
    Electronic Resource
    Electronic Resource
    Pyrolysis of 1,1,1-Trichloroethane in the absence and the presence of added HCl and/or CCl4 (1989)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 21 (1989), S. 575-591 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The title reaction has been studied in a static quartz reaction vessel between 587 and 658 K at pressures between 40 and 152 torr. The dehydrochlorination is the only significant reaction and is autoaccelerated by the produced HCl. Numerical modelling indicates that the Rice-Herzfeld mechanism, generally used for describing the pyrolysis of halogenated ethanes, has to be completed in the case of CC13CH3 with additional transfer reactions converting “dead” radicals into chain carriers and vice-versa. The numerical simulation fits the experimental results, in the absence as well as in the presence of different amounts of added HCl. The dehydrochlorination is also accelerated by the addition of CCl4, which can be explained in terms of additional elementary steps involving · CCl3 radicals.
    Additional Material: 9 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550210708
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  • 6
    Electronic Resource
    Electronic Resource
    Kinetics of the diels-alder addition of ethene to cyclohexa-1,3-diene and its reverse reaction in the gas phase (1980)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 12 (1980), S. 253-259 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The addition of ethene to cyclohexa-1,3-diene has been studied between 466 and 591 K at pressures ranging from 27 to 119 torr for ethene and 10 to 74 torr for cyclohexa-1,3-diene. The reaction is of the “Diels-Alder” type and leads to the formation of bicyclo[2.2.2]oct-2-ene. It is homogeneous and first order with respect to each reagent. The rate constant (in l./mol sec) is given by\documentclass{article}\pagestyle{empty}\begin{document}$$ \log _{10} k_a = - (25,970 \pm 50)/4.576{\rm T + }(6.66 \pm 0.02) $$\end{document}The retron-Diels-Alder pyrolysis of bicyclo[2.2.2]oct-2-ene has also been studied. In the ranges of 548-632 K and 4-21 torr the reaction is first order, and its rate constant (in sec-1) is given by\documentclass{article}\pagestyle{empty}\begin{document}$$ \log _{10} k_p = - (57,300 \pm 100)/4.576{\rm T + }(15.12 \pm 0.04) $$\end{document}The reaction mechanism is discussed. The heat of formation and the entropy of bicyclo[2.2.2]oct-2-ene are estimated.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550120406
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  • 7
    Electronic Resource
    Electronic Resource
    Kinetics, mechanism, and endo selectivity of Diels-Alder reactions of alkylmonosubstituted ethenes with cyclohexa-1,3-diene in the gas phase (1984)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 16 (1984), S. 93-102 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reactions where Y = CH3 (M), C2H5 (E), i—C3H7 (I), and t—C4H9 (T) have been studied between 488 and 606 K. The pressures of CHD ranged from 16 to 124 torr and those of YE from 57 to 625 torr. These reactions are homogeneous and first order with respect to each reagent. The rate constants (in L/mol·s) are given by \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NMBO}} = - {{\left( {26530 \pm 80} \right)} \mathord{\left/ {\vphantom {{\left( {26530 \pm 80} \right)} {4.576T + \left( {6.05 \pm 0.03} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.05 \pm 0.03} \right)}} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XMBO}} = - {{\left( {28910 \pm 130} \right)} \mathord{\left/ {\vphantom {{\left( {28910 \pm 130} \right)} {4.576T + \left( {6.32 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.32 \pm 0.05} \right)}} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NEBO}} = - {{\left( {26150 \pm 120} \right)} \mathord{\left/ {\vphantom {{\left( {26150 \pm 120} \right)} {4.576T + \left( {5.85 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.85 \pm 0.05} \right)}} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XEBO}} = - {{\left( {28560 \pm 120} \right)} \mathord{\left/ {\vphantom {{\left( {28560 \pm 120} \right)} {4.576T + \left( {6.07 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.07 \pm 0.05} \right)}} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NIBO}} = - {{\left( {26560 \pm 80} \right)} \mathord{\left/ {\vphantom {{\left( {26560 \pm 80} \right)} {4.576T + \left( {5.57 \pm 0.03} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.57 \pm 0.03} \right)}} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XIBO}} = - {{\left( {28350 \pm 100} \right)} \mathord{\left/ {\vphantom {{\left( {28350 \pm 100} \right)} {4.576T + \left( {5.47 \pm 0.04} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.47 \pm 0.04} \right)}} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm NTBO}} = - {{\left( {28920 \pm 50} \right)} \mathord{\left/ {\vphantom {{\left( {28920 \pm 50} \right)} {4.576T + \left( {5.86 \pm 0.02} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {5.86 \pm 0.02} \right)}} $$\end{document} \documentclass{article}\pagestyle{empty}\begin{document}$$ {\rm log}_{{\rm 10}} k_{{\rm XTBO}} = - {{\left( {32890 \pm 120} \right)} \mathord{\left/ {\vphantom {{\left( {32890 \pm 120} \right)} {4.576T + \left( {6.19 \pm 0.05} \right)}}} \right. \kern-\nulldelimiterspace} {4.576T + \left( {6.19 \pm 0.05} \right)}} $$\end{document} The Arrhenius parameters are used as a test for a biradical mechanism and to discuss the endo selectivity of the reactions.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550160202
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  • 8
    Electronic Resource
    Electronic Resource
    Kinetics and mechanisms of the reaction of acetylene with cyclohexa-1,3-diene and the decomposition of bicyclo[2.2.2]-octa-2,5-diene in the gas phase (1982)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 14 (1982), S. 997-1005 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction of acetylene (A) with cyclohexa-1,3-diene (CHD) has been studied between 450 and 592 K. The pressures of A ranged from 25 to 112 torr and those of CHD from 8 to 62 torr. The reaction yields only ethene (E) and benzene (B) instead of bicyclo[2.2.2]octa-2,5-diene (BOD), the product that is expected for a 1,4,1′,2′ addition of the Diels-Alder type. It is first order with respect to each reagent. The rate constant (in L/mol·s) is given by \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k = - (27,150 \pm 120)/4.576T + (7.49 \pm 0.05)$$\end{document} The thermal decomposition of BOD has also been studied. In the ranges of 354-435 K and 0.5-6 torr, the reaction is first order and results in the formation of equal amounts of B and E as the reaction of A with CHD does. Its rate constant (in s-1) is given by \documentclass{article}\pagestyle{empty}\begin{document}$$\log _{10} k_d = - (32,520 \pm 40)/4.576T + (14.06 \pm 0.02)$$\end{document} The following consecutive reactions are proposed for the reaction between A and CHD: where BOD is the primary product that is too unstable to be detected. This implies that the rate constant k is equal to ka. The reaction mechanisms and the strain energy in BOD are discussed.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550140905
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  • 9
    Electronic Resource
    Electronic Resource
    Gas phase kinetic and thermochemical data for endo- and exo-5-monosubstituted bicyclo[2.2.2]Oct-2-Enes (1986)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 18 (1986), S. 537-545 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The thermal reactions of endo- and exo-5-Y bicyclo[2.2.2]oct-2-enes (NYBO and XYBO) where Y = methyl, ethyl, and isopropyl have been studied in the gas phase between 567 and 695 K. For both isomers they are parallel first-order retro-Diels-Alder reactions with elimination of ethene (E) and monosubstituted ethene (YE).The observed Arrhenius parameters are used to discuss the mechanism and to estimate the heats of formation and the entropies of NYBO and XYBO. Group values are proposed for estimation of these thermochemical data for compounds of the same type by means of the methods of Benson.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550180504
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  • 10
    Electronic Resource
    Electronic Resource
    Kinetics, mechanism, and stereochemistry of Diels-Alder reactions of carbonyl-substituted ethenes with cyclohexa-1,3-diene in the gas phase (1987)
    New York, NY : Wiley-Blackwell
    International Journal of Chemical Kinetics 19 (1987), S. 1063-1072 
    Details
    ISSN: 0538-8066
    Keywords: Chemistry ; Physical Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The kinetics of the Diels-Alder additions of CH2 — CHCHO, CH2—C(CH3)CHO, and CH2—CHC(CH3)O to cyclohexa-1,3-diene (CHD) have been studied in the gas phase. The stereochemistry and the mechanism of these reactions are discussed. In contrast with other Diels-Alder additions involving CHD as diene, a biradical mechanism does not fit the experimental results.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/kin.550191203
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