Preparation of BPA Epoxy Resin/POSS Nanocomposites and Nonisothermal Co-curing Kinetics with MeTHPA

Polyhedral oligomeric silsesquioxanes epoxy resin (GM-POSS) was prepared from 3-glycidyloxypropyl-trimethoxysilane (GTMS) and methyl triethoxysilane (MTES) by hydrolytic condensation. GM-POSS was characterized using liquid chromatography/mass spectrometry (LC/MS). The epoxy value of GM-POSS is 0.23 mol/100 g. The LC/MS analysis indicates that T(8) and T(9) cages are the majority and contain some amount of T(10). The co-cured nanocomposites of BPA epoxy resin with GM-POSS using 3-methyl-tetrahydrophthalic anhydride (MeTHPA) as the curing agent were prepared and the co-curing kinetics was investigated by nonisothermal differential scanning calorimetry (DSC). The relationship between apparent activation energy Ea and the conversion a was obtained by the isoconversional method of Kissinger, and Ea is 68-78 kJ/mol. The results show that these curing reactions can be described by the Sestak-Berggren (S-B) equation, which includes two parameters, m and n. For different mass ratio of GM-POSS and BPAER, the two reaction orders, m and n, are in the range of 0.25 similar to 0.42 and 0.52 similar to 1.28, respectively. The curing kinetics can be described by the equations