Oligosilylarylnitrile: The Thermoresistant Thermosetting Resin with High Comprehensive Properties

摘要

One of the highest thermoresistant thermosetting resins ever studied so far, oligosilylarylnitrile resin, was investigated first in this study. Oligosilylarylnitrile was synthesized by lithium-reduced Wurtz-Fittig condensation reaction, and the prepared viscous resin exhibited moderate rheological behaviors while heated purely or together with 20% polysilazane as a cross-linking agent. The thermal curing temperature's were found by differential scanning calorimetry at 268 degrees C (pure) and 158 degrees C (with the polysilazane cross-linking agent), which is comparably close to that of polysilylarylacetylene resin (normally at 220-250 degrees C) but much lower than those of polyimide and phthalonitrile resins (normally 300 degrees C), indicating the admirable material processability of oligosilylnitrile. The cured oligosilylarylnitrile resins have extremely high thermal resistance, indicated by the results of thermogravimetric analysis (the mass residue at 800 degrees C is 90% under N-2) and dynamic mechanical analysis (the glass transition temperature is 420 degrees C): The mechanical property of the oligosilylarylnitrile-matrixed silica-cloth reinforced laminate is comparably close to those of polyimide and phthalonitrile but much higher than that of polysilylarylactylene, indicating the enviable thermal and mechanical properties of oligosilylnitrile. Thus, among the high-temperature resins ever studied so far, the oligosilylarylnitrile resin was found to have the almost best comprehensive characteristics of processability and properties.