Ceramifiable and mechanical properties of silicone rubber foam composite with frit and high silica glass fiber

In this paper, ceramifiable silicone rubber foam composite was prepared by silicone rubber, fumed SiO₂, talc, frit, high silica glass fiber, foaming and vulcanizing agents. Thermal property, micromorphology, phase transformation and compressive strength of pyrolysis residues at different temperatures were discussed. Thermogravimetric analysis (TGA) results indicated that the amount of ceramic residues increased from 34.5% to 41.1% at 1000 °C with the increase of frit content, whereas T₅ and T_max decreased by 43°C and 103°C, respectively. SEM images showed that pore size became well-distributed by adding frits to the silicone rubber. And after pyrolysis at 1000°C, bridged structure was formed well, which made the structure of residues be coherent and integrated. XRD tests indicated that new crystalline phase, MgSiO₃, was appeared at above 1000°C. The effect of frit on compressive strength of composite at room temperature was little, but there was a great improvement after being treated at high temperature, especially at 1000°C. (paper)