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:
An infrared absorption spectroscopy study of the curing (gelation and postcure) kinetics of a high (4.7) epoxide/hydroxyl group-ratio diglycidyl ether of bisphenol A (DGEBA)-mixed anhydride epoxy resin system is reported. Peak assignments to molecular vibrational modes are given for the range 400-4000 cm-1, and the optical density behavior of all peaks during reaction is discussed in detail. Chemical reaction was found to follow consecutive-step addition esterification and simultaneous addition etherification. Epoxide hydroxyl-group and carboxylic acid dimer hydrogen bonding was found to occur. The gelation phase of reaction is complex, exhibiting rapid initial hydroxyl-anhydride reactions followed by S-shaped kinetics approaching an incompletely reacted limit. Postcure exhibits functional group kinetic behavior similar to that occurring in low epoxide/hydroxyl group-ratio bisphenol A epoxy resin-phthalic anhydride systems and produces similar final chemical structures. The reaction behavior of low and high epoxide/hydroxyl group-ratio bisphenol A epoxy resin-anhydride systems arises from an hydroxyl group-limited inhomogeneous reaction mechanism involving bisphenol A epoxy resin molecular aggregates. The importance of free hydroxyl group content is discussed.
Additional Material:
10 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/app.1981.070261226
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