Enhanced compatibility and morphology evolution of the hybrids involving phenolic resin and silicone intermediate

In this paper, hybrids containing novolac phenolic resin (NR) and silicone intermediate (SI) were investigated. Compatibility between the two components was enhanced by modifying NR with a coupling agent, γ-(2,3-epoxypropoxy) propyltrimethoxysilane (KH560). SI with silanol groups was synthesized by the hydrolysis of phenyltrimethoxysilane and dimethyldimethoxysilane. Different amount of SI was blended with modified NR, and the corresponding yellow transparent samples were obtained and used for the subsequent curing and microscopic observation. SI-rich nanoparticles were found to be evenly dispersed in the initial sample and further coarsened to nano- and micro-particles. The size and amount of the particles increased with the SI loading. The morphology evolution mechanism was discussed based on microscopic observation and chemical reaction processes. Thermal stability of the cured hybrids was characterized by thermalgravimetric analysis. Temperatures at 5% and 10% mass loss and residual weight at 900 °C were found to increase with the SI loading. Furthermore, carbon retention after high temperature oxidation was also increased.