Epoxy-polyhedral oligomeric silsesquioxanes (G-POSS) monomers were synthesized from 3-glycidyloxypropyl-trimethoxysilane (GTMS) by hydrolytic condensation. The G-POSS-containing nanocomposite film was prepared by hybrid cationic ring-opening polymerization from G-POSS and arms. The curing reaction kinetics, dynamical mechanical properties, thermal degradation properties and morphological structures of G-POSS/GTMS system were investigated by non-isothermal DSC, dynamic mechanical analysis (DMA), TGA, AFM and SEM. The results show that the curing reaction activation energy Ea decrease when GTMS is added into the reaction system, and the curing reaction kinetics can be simulated by the Sestak-Berggren (S-B) model. DMA and TG analysis results show that the glass transition temperature T-g and initial thermal decomposition temperature T-id of materials is 4 and 65 degrees C higher than pure polymerized G-POSS, respectively, when the content of GTMS is 2 wt%. AFM analysis shows that the membrane surface of pure polymerized G-POSS has uniform distribution of less than 1.76 nm high protrusion. SEM analysis shows that have uniform spherical particle distribution on the membrane surface with about 20-25 nm diameter. (C) 2014 Elsevier B.V. All rights reserved.