(C)元素高分子(主链不含C) CHa Ch2 Ch chacha cha cha CH2 Ch2 ChCH Si 聚二甲基硅氧烷 C Cl Cl P=N一P=N—P=N-P=N—P=N一P=N 聚氯化膦腈Si O O O O O O Si Si Si Si Si CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 CH3 聚二甲基硅氧烷 P = N Cl Cl P = N Cl Cl P = N Cl Cl P = N Cl Cl P = N Cl Cl P = N Cl Cl 聚氯化膦腈 (C) 元素高分子（主链不含C）