| 摘要 |
PURPOSE:The titled polycarbosilane being excellent in heat and oxidation resistance and generating much burning residue in a non-oxidizing atmosphere, prepared by polymerizing a mixture of a specified polysilane and a polyborosilane containing phenyl groups in at least part of the Si side chains. CONSTITUTION:A polysilane of formulaI(wherein R1 and R2 are each H, CH3, C2H5 or C6H5 and n >=3) is mixed with 0.01-15wt% polyborosilane, number- average MW of 500-10,000, which has skeletal components containing B, Si and O, and has phenyl groups on at least part of the Si side chains, and the mixture is polymerized at 250-500 deg.C for 3-10hr in an atmosphere inert to the reactions to obtain a polycarbosilane partially containing siloxane bonds, comprising structural units of formulas II and III (wherein R3 and R4 are each R1) and having a ratio of formula II/formula III of 5-200:1, a number-average MW of 500-10,000, and an intrinsic viscosity of 0.01-1.50. |
