Epoxy networks modified by multifunctional polyhedral oligomeric silsesquioxanes (POSS) containing amine groups

The hydrolytic condensation of a precursor synthesized by the reaction of equimolar amounts of (3-aminopropyl)triethoxysilane and phenylglycidylether led to a distribution of polyhedral oligomeric silsesquioxanes (POSS) containing 8-11 Si atoms, functionalized with amine groups. About 57% of the NH functionalities were active for reaction with epoxy groups. The multifunctional amine-POSS was used to modify an epoxy network obtained by the homopolymerization of diglycidylether of bisphenol A initiated by benzyldimethylamine. The main effect of POSS modification was an increase in both the glassy and rubbery modulus explained, respectively, by the increase in cohesive energy and crosslink densities.