Curing reactions of liquid hydridopolycarbosilanes with vinyl or allyl groups

Abstract

Liquid hydridopolycarbosilanes (LHPCS) with vinyl or allyl groups have attracted significant research interest due to their low curing temperature and high ceramic yield. In this study, allyl‐terminated hydridopolycarbosilane (AHPCS) and vinyl‐terminated hydridopolycarbosilane (VHPCS) were prepared by the Grignard coupling reaction and characterized by NMR and Fourier infrared spectroscopy (FTIR). And the curing reactions of AHPCS and VHPCS with or without initiators (dicumyl peroxide [DCP], tert‐Butyl peroxybenzoate [TBPB]) or Karstedt catalyst were investigated using differential scanning calorimetry and in‐situ FTIR. The main curing reactions of VHPCS and AHPCS are the double bond free radical polymerization and hydrosilylation reaction, respectively. The addition of initiators and Karstedt catalyst could promote the corresponding curing reaction and increase the weight residual at 1000°C. The thermal properties of the cured resins were investigated by thermogravimetric analysis. The addition of initiators and catalyst could significantly increase the weight residual of VHPCS and AHPCS, respectively. The addition of the Karstedt catalyst increased the weight residual of AHPCS from 75.6% to 83.1%. In addition, the addition of TBPB and DCP increased the weight residual of VHPCS from 74.2% to 81.2% and 80.2%, respectively.