Study of Catalytic Effect of Nanolayered Montmorillonite Organoclays in Epoxy Polymer

This paper is about the study of catalytic effect of nanolayered montmorillonite- (MMT-) based organoclays (OCs) in epoxy polymer by directly monitoring their exothermic temperature versus time during curing. Untreated clays (UCs) of MMT were also filled in the epoxy polymer for comparative study. OCs and UCs were individually filled in epoxy polymer from 0 wt.% to 5 wt.%, and the curing characteristics were examined. The cure behavior of epoxy-OC composites changes as a function of OC concentration. Among the epoxy-OC systems, improved curing reaction was observed at 3 wt.% OC-filled epoxy composites. Addition of OC above 3 wt.% in epoxy reduces its catalytic effect due to presence of two types of cross-linking, namely, intergallery and extragallery cross-linking reactions. The curing behaviours of epoxy-UC composites were almost similar to those of pure epoxy polymer, and hence the results suggest that UC does not act as catalyst in epoxy polymer. The cured composite series was examined by studying their structure and morphology using X-ray diffraction (XRD), transmission electron microscopy (TEM) analysis, and the Fourier transform infrared (FTIR) spectroscopy.