Maryam Seyri - Composites Department, Iran Polymer and Petrochemical Institute, P. O. Box: ۱۴۹۷۵/۱۱۲, Tehran, Iran,
Mohammad Hosain Beheshty
Mahdieh Shervin

The type of epoxy resin and the distribution of its molecular weight affect on properties and morphology of an epoxy system. In this study, we prepared five epoxy resin systems, in order to investigate the effect of epoxy resin and its molecular weight on physical and mechanical properties. GPC, DSC, AFM, gel time, and rheological tests were used to characterize these systems. Our formulations consist of two types of epoxy resin and their mixtures based on diglycidyl ether of bisphenol A (DGEBA). Results of GPC test showed that, by increasing the content of epoxy resin with high molecular weight, the molecular weight distribution moved from narrow to the broad and bimodal distribution. Results of gelation tests showed that by increasing the molecular weight of the epoxy resin, gel time was reduced. Results also show that the difference of gelation time at higher temperature for different compositions is not significant. It is interesting that the kind of molecular weight distribution has a significant effect on nanostructure of epoxy resin which was revealed by AFM

Epoxy Resin, Molecular Weight, Gel Time, Curing, Morphology