Nonisothermal cocuring behavior and kinetics of epoxy resin/3‐glycidyloxypropyl‐POSS with MeTHPA

Abstract 3‐Glycidyloxypropyl‐polyhedral oligomeric silsesquioxanes (G‐POSS) was prepared from 3‐glycidyloxypropyl‐trimethoxysilane (GTMS) by hydrolytic condensation. The cocuring behavior and kinetics of G‐POSS with bisphenol‐A epoxy resin (BPAER) using 3‐methyl‐tetrahydrophthalic anhydride (MeTHPA) as curing agent were investigated by nonisothermal differential scanning calorimetry (DSC) and torsional braid analysis (TBA). The face distribution of silicon in the cured products was characterized by energy dispersive X‐ray spectrometry (EDS). The results show that the compatibility of G‐POSS with BPAER is very well and can cocure. The curing mechanism was proposed. The relationship of E_a and conversion α can be obtained by the isoconversional method of Kissinger. These curing reactions can be described by the Šesták–Berggren (S–B) equation and can be depicted by the following equation: $ \font\abc=cmmib10\def\bi#1{\hbox{\abc #1}}{\bi d\alpha \over \bi dt} {=} A\ {\bf exp} (-{E_a \over RT}) {{\alpha}}^m ({\bf 1}-a)^n $. TBA analysis indicated that T_g was decreased when the contents of G‐POSS is over to 30 wt%. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers