Effect of Acetone Content on the Preparation Period and Curing/Pyrolysis Behavior of Liquid Polycarbosilane

A novel approach was proposed to increase the compactness, shorten the preparation period, and reduce the preparation cost by introducing acetone to optimize the polycarbosilane impregnation process. The porosity in internally derived SiC ceramics decreased and pore size was limited by using this new method, which led to higher compactness. Meanwhile, with the increase in acetone content, the viscosities of polycarbosilane and the wetting angles of polycarbosilane/graphite decreased appreciably, and the viscosity was 6.0 mPa·s with 40 wt.% acetone added—a factor of about 30 lower than that of original polycarbosilane. The wetting angle between polycarbosilane and graphite significantly decreased by 40%, which resulted in an enhancement in the impregnation efficiency of liquid polycarbosilane and a much shorter preparation period. This work provides a convenient and efficient method that is assistant during the practical production process of carbon fiber reinforced ceramic matrix composites (CMCs).Keywords:polycarbosilane;acetone;viscosity;wettability;impregnation efficiency