Cure modeling and monitoring of epoxy/amine resin systems. II. Network formation and chemoviscosity modeling

Autor: Panagiotis I. Karkanas, Ivana K. Partridge
Rok vydání: 2000
Předmět:
Zdroj: Journal of Applied Polymer Science. 77:2178-2188
ISSN: 1097-4628
0021-8995
DOI: 10.1002/1097-4628(20000906)77:10<2178::aid-app11>3.0.co;2-0
Popis: The glass transition temperature (Tg) advancement and the chemoviscosity development under isothermal conditions have been investigated for four epoxy/amine systems, including commercial RTM6 and F934 resins. Differential scanning calorimetry (DSC) was the thermoanalytical technique used to determine the Tg advancement and rheometry the technique for the determination of the chemoviscosity profiles of these resin systems. The complex cure kinetics were correlated to the Tg advancement via an one-to-one relationship using Di Benedetto's formula. It was revealed that the three-dimensional network formation follows a single activated mechanism independent of whether the cure kinetics follow a single or several activation mechanisms. The viscosity profiles showed the typical characteristics of epoxy/amine cure. A modified version of the Williams-Landel-Ferry equation (WLF) was adequate to model the viscosity profiles of all the resin systems, in the temperature range 130 to 170°C, with a very good degree of accuracy. The parameters of the WLF equation were found to vary in a systematic manner with cure temperature. Further correlation between Tg and viscosity showed that gelation, defined as the point where viscosity reaches 104 Pas, occurs at a unique Tg value for each resin system, which is independent of the cure conditions. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 2178–2188, 2000
Databáze: OpenAIRE
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