Synthesis, curing behavior and thermal properties of silicon-containing hybrid polymers with Si-C≡C units

摘要

Three novel kinds of linear silicon-containing hybrid polymers with Si—C≡C units were synthesized by polycondensation reactions using the Grignard reagent method. All the polymers were thermosetting, highly heat-resistant, moldable and easily soluble in common organic solvents. The structure, curing behavior, thermal and oxidative properties were characterized using Fourier transform infrared spectroscopy,~1H NMR, ~(13)C NMR, gel permeation chromatography, differential scanning calorimetry and thermogravimetric analysis. The results obtained can provide theoretical guidance for determining the curing of the resin system. In addition, the cured polymers exhibit excellent thermal and oxidative stabilities with temperatures of 5% weight loss (T_(d5)) above 480 °C and 450 °C in nitrogen and air respectively; the residues at 1000 °C were above 70.0% and 45.0% respectively. The thermal and oxidative stabilities of the polymers are attributed to a crosslinking reaction between the Si—H and C≡C bonds or C≡C bonds. These polymers have the potential for use as high-temperature-resistant resins and ceramic precursors.