An analysis of the substitution effects involved in diepoxide‐diamine copolymerization reactions

Charlesworth, John M.

doi:10.1002/pol.1980.170180221

Cited by 63 publications

(28 citation statements)

References 18 publications

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“…-d e / d t = e { klalOH + k2a20H + k;al + k ; u 2 } ( 8 ) -d a l / d t = e { 2kla10H + k2u20H + 2k;ul + kLa2} ( 9 ) A factor of 2 appears in eq. ( 9 ) because when a primary amino-hydrogen has reacted, the other automatically loses its quality of primary amino-hydrogen (10) da,/dt = e { k2u20H + k ; a 2 } (11)…”

Section: Determination Of Kinetic Constantsmentioning

confidence: 99%

Reactions in aminosilane–epoxy prepolymer systems I. Kinetics of epoxy–amine reactions

Sérier

Pascault

1991

J. Polym. Sci. A Polym. Chem.

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SYNOPSISThe reactions of an epoxy prepolymer based on bisphenol A diglycidylether (DGEBA) with y-aminopropyltriethoxysilane ( y-APS) are studied. The results of different techniques are compared: size exclusion chromatography, differential scanning calorimetry, chemical titration, and Fourier Transform Infrared absorption. Epoxy amine reactions are shown to be faster than the crosslinking reactions between alkoxysilane and hydroxy groups, and thus, can be studied separately. The reactivity of the epoxy group in DGEBA is compared with that of phenylglycidylether ( P G E ) . And the reactivity of the amine group of 7-APS is compared with that of hexylamine. The kinetic constants are calculated with a mechanism which takes into account both the catalytic and noncatalytic reactions. The ratio r = k,/ kl of the reactivity of the secondary to the primary amino-hydrogens was also determined. The values of r are 1.4 for hexylamine and 1.2 for y-APS. The reactivities of the epoxy groups are the same for both PGE and DGEBA.

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Section: Determination Of Kinetic Constantsmentioning

confidence: 99%

Reactions in aminosilane–epoxy prepolymer systems I. Kinetics of epoxy–amine reactions

Sérier

Pascault

1991

J. Polym. Sci. A Polym. Chem.

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“…The relative reaction rate of PA and SA determines the morphology of the network5, 6 and is an important input parameter for kinetic simulations designed to generate network structure information;7 it has been the subject of many studies 8–12. However, because of variations in the analytical techniques and kinetic models, the results are contradictory in many cases.…”

Section: Introductionmentioning

confidence: 99%

Influence of substituents on the kinetics of epoxy/aromatic diamine resin systems

Uhlherr

Varley

et al. 2004

J. Polym. Sci. A Polym. Chem.

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Eleven different epoxy/diamine systems, including tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM), triglycidyl p‐aminophenol (TGAP), and diglycidyl ether of bisphenol A (DGEBA) with 4,4′‐diaminodiphenylsulfone (DDS), diethyltoluenediamine (DETDA), dimethylthiotoluenediamine (DMTDA), and meta‐phenylenediamine (m‐PDA), were studied with near‐infrared spectroscopy at different temperatures. The reactivities of the epoxies were determined and found to be in the following order when reacted with the same amine: DGEBA > TGAP > TGDDM. When the primary amine was reacted with the same epoxy, the order was DETDA > DDS > DMTDA; for the secondary amine, the order was DETDA > DMTDA > DDS. The relative reaction rates of the secondary amine to the primary amine were compared and discussed in terms of the structural differences and the corresponding substitution effect. It was concluded that the increase in the secondary amine reactivity of DETDA and DMTDA was caused by the deconjugation of the benzene‐ring π electrons from the lone pair on the N atom. The overall order of the secondary amine relative reactivity was DMTDA > DETDA > DDS for the same epoxy and TGDDM > TGAP > DGEBA for the same amine. The m‐PDA systems had no significant positive or negative substitution effects. Molecular orbital calculations were performed, and the results showed the most significant deconjugation effect in the secondary amine of DETDA. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 3143–3156, 2004

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“…Monoamines like ethanol amine (EA) react cleanly with pure DGEBA at 150–180 °C in the melt, in a conventional extruder and without any catalyst, to yield a soluble poly(hydroxyl amino ether) TP 4,5. The mechanism of the reactions between NH 2 and oxirane are well established 6–11. Beside these reactions between primary and secondary amino groups and oxirane, a side reaction between the formed hydroxyl groups and oxirane can occur (Equation (2)).…”

Section: Introductionmentioning

confidence: 99%

Post‐Crosslinkable Blends: Reactions Between a Linear Poly(hydroxyl‐amino ether) and a Diepoxy

Constantin¹,

Fenouillot²,

Pascault

et al. 2004

Macro Materials & Eng

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Summary: A thermoplastic poly(hydroxyl‐amino ether) polymer (BLOX) was blended with a diglycidyl ether of bisphenol A monomer (DGEBA). This system may be used as a crosslinkable thermoplastic. It means that it may be processed in an extruder like a classic thermoplastic, and cured by etherification reactions initiated by tertiary amine groups of the BLOX in a second step, to produce a material with good mechanical properties. In order to understand and quantify the etherification reactions occurring at high temperature (135 °C), between epoxy groups of the diepoxy and hydroxyl groups of the thermoplastic, a model system was studied based on DGEBA in excess and ethanolamine. In the model system the rate of the etherification reaction was well described by a second‐order kinetic equation. The specific rate constants and the epoxy conversion at the gel were related to the polarity of the reactive medium. The polyetherification occurring in the DGEBA‐BLOX system could also be fitted with a second‐order kinetics. A significant increase in the reaction rate was observed when using high BLOX concentrations. magnified image

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An analysis of the substitution effects involved in diepoxide‐diamine copolymerization reactions

Cited by 63 publications

References 18 publications

Reactions in aminosilane–epoxy prepolymer systems I. Kinetics of epoxy–amine reactions

Reactions in aminosilane–epoxy prepolymer systems I. Kinetics of epoxy–amine reactions

Influence of substituents on the kinetics of epoxy/aromatic diamine resin systems

Post‐Crosslinkable Blends: Reactions Between a Linear Poly(hydroxyl‐amino ether) and a Diepoxy

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