聚硅氧烷陶瓷前驱体的制备及其热解转化行为研究

Preparation and Pyrolytic Conversion Behavior of Polysiloxane Ceramic Precursor

采用阳离子开环聚合反应制备合成了侧基含Si—H、Si—CH=CH_2基团的线性结构的聚硅氧烷陶瓷前驱体(PSO),对合成产物的结构及热解转化行为进行了相关研究.结果表明:对于含有Si—H、Si—CH=CH_2活性基团的硅氧烷在Karstedt催化剂作用下能有效固化,固化物具有高热稳定性和高的陶瓷产率;热解温度达1 300,℃时裂解产物从非晶态到晶态的转变,出现了Si O_2、β-Si C以及游离碳的衍射峰.

The linear Polysiloxane ceramic precursor containing Si—H and Si—CH=CH_2 groups was prepared by cationic ring-opening polymerization reaction. The structure and pyrolytic behavior of the product were studied. The results showed that： PSO containing Si—H and Si—CH=CH_2 groups have effective curing in the presence of Karstedt catalyst; the cured PSO had a high thermal stability and a high cer,amic yield; when the pyrolysis temperature reached 1 300 ℃, the pyrolysis product started a transition from amorphous to crystalline state, and the diffraction of Si O_2, β-Si C and free carbon appeared.