A characteristic of so-called melting gels is that the gels, which are rigid at room temperature, are able to soften and resoften at temperatures around 110 [degrees]C. However, after consolidation at temperatures higher than 150 [degrees]C, the gels no longer resoften. Two systems of melting gels were investigated: phenyltrimethoxysilane (PhTMS)–diphenyldimethoxysilane (DPhDMS) and phenyltriethoxysilane (PhTES)–diphenyldiethoxysilane (DPhDES). The influence of disubstituted versus monosubstituted alkoxide on the softening behavior and the temperature of decomposition was studied. The consolidation temperature increased as the amount of disubstituted alkoxide increased, while the decomposition temperature increased only slightly. In general, the ethoxy-containing gels (maximum at 150[degrees]C) consolidated at lower temperatures than the methoxy-containing gels (maximum at 180[degrees]C).
Jitianu, Andrei; Amatucci, Glenn; and Klein, Lisa C., "Phenyl-Substituted Siloxane Hybrid Gels that Soften Below 140[degrees]C" (2009). CUNY Academic Works.