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Isothermal transitions of a thermosetting systemA study of the curing reactions of a cycloaliphatic epoxy resin/anhydride system by torsional braid analysis showed the existence of two critical isothermal temperatures - namely, the maximum glass transition temperature of the thermoset system and the glass transition temperature of the material at its gel point. Two rheologically active kinetic transitions occur during isothermal cure which correspond to gelation and vitrification. Three types of isothermal behavior occur. Methods for determining the time to gel and the time to vitrify, and also the two above-mentioned critical isothermal temperatures, have been developed. The time to gel obeyed the Arrhenius relationship, whereas the time to vitrify passed through a minimum. Application of these results to thermosetting systems in general is discussed in terms of the influence of molecular structure on the values of the critical isothermal temperatures.
Document ID
19740061329
Document Type
Reprint (Version printed in journal)
Authors
Gillham, J. K.
Benci, J. A. (Princeton University Princeton, N.J., United States)
Noshay, A. (Union Carbide Corp. Chemicals and Plastics Div., Bound Brook, N.J., United States)
Date Acquired
August 7, 2013
Publication Date
January 1, 1974
Publication Information
Publication: Journal of Applied Polymer Science
Volume: 18
Subject Category
CHEMISTRY
Funding Number(s)
CONTRACT_GRANT: N00014-67-A-0151-0024
CONTRACT_GRANT: NGR-31-001-221
Distribution Limits
Public
Copyright
Other