陶瓷先驱体含锆聚硅烷的电化学合成与表征

ELECTROCHEMICAL SYNTHESIS AND CHARACTERIZATION OF POLYSILANE WITH ZIRCONIUM

采用电化学合成法,以三氯甲基硅烷、氯丙烯、环戊二烯和四氯化锆为单体合成出含锆聚硅烷,通过FTIR,UV,NMR,XRD等表征了其结构.测定了产物的各元素含量和双键含量,以及分子量和分子量分布,并对产物进行了交联固化和高温裂解实验.结果表明,含锆聚硅烷双键保留率为10.8%,锆含量为4.11%.含锆聚硅烷能溶于常见的溶剂,成膜性能良好.双键起到了自交联的作用,无需使用交联剂二乙烯基苯;双键和锆的引入使聚硅烷获得了较高的质量保留率和陶瓷产率,裂解产物主要为β-SiC和ZrC,是优良的陶瓷先驱体.

A polysilane with zirconium was synthesized by electrochemical method,using methyltrichlorosilane,allylchloride,Cyclopentadiene and Zirconium tetrachloride as monomers.The product was characterized by FTIR,UV,NMR and XRD.Its double-bond,elements content,molecular weight and molecular weight distribution were determined.The cross-linking and pyrolysis of it were studied.The results show that the product yield is 71.2%,the retaining ratio of double bonds is 10.8%,the Zr content is 4.11% and Molecular weight and molecular weight distribution are 3746 and 3.24.It can dissolve in toluene,THF,chloroform and other common organic solvents,and has excellent film-forming properties.The introduction of cyclopentadienyl and allyl makes its maximum absorption wavelength widen and have a high degree of red shift.Cyclopentadienyl and Zr form big π bond in the electrosynthesis process,leading to support the formation of cross-linking system.Double bonds can play the role of self-crosslinking,eliminating the need for the use of cross-linking agent.The introduction of double bond and Zr in polysilane brings forth much higher mass retaining ratio and better ceramic yield.It can be used as ceramic precursor,pyrolysis products are mainly SiC and ZrC.In addition,there are excess Si and SiO2.It provides a new way for the synthesis of polysilanes with unsaturated functional groups and heterogeneous elements.