Highly thermally stable mesoporous Poly(cyanate ester) featuring double-decker–shaped polyhedral silsesquioxane framework

Abstract

In this study we prepared cyanate ester–functionalized double-decker silsesquioxane (DDSQ) nanoparticles through a sequence of hydrosilylation of nadic anhydride (ND) with DDSQ and then treat with 4-aminophenol to provide DDSQ-ND-OH, and reaction with cyanogen bromide (BrCN) to form DDSQ-ND-OCN (a bis-phenyl cyanate ester DDSQ). After thermal curing of DDSQ-ND-OCN, we obtained mesoporous poly(cyanate ester) (PCE)/DDSQ frameworks that displayed high thermal stabilities and char yields since the inorganic DDSQ nanoparticles were dispersed in the PCE matrix homogeneously, as revealed using electron microscopy. Thermal polymerization at 210 °C provided a PCE/DDSQ framework having a thermal decomposition temperature (516 °C) and char yield (70 wt%); these values increased to 600 °C and 81 wt%, respectively, after thermal treatment at 420 °C. More interestingly, these mesoporous PCE/DDSQ frameworks displayed electrochemical properties better than those of other non-carbonized materials.