摘要
聚碳硅烷(PCS)是碳化硅(SiC)纤维和陶瓷的重要先驱体之一。以PCS作为先驱体制备SiC纤维和陶瓷时,通常存在陶瓷产率低的问题,进而影响最终产品质量。利用含铑催化剂以及偶氮二异丁腈,使通常不易进行硅氢化反应的丙烯腈和PCS发生反应,将氰基引入PCS分子中,合成出新型含氰基聚碳硅烷(PCSCN)先驱体。与PCS相比,以含铑催化剂合成的PCSCN的陶瓷产率可大幅提高至80%以上。用红外、核磁分析了PCSCN的分子结构,结果表明两种催化剂引发的硅氢化反应均是以α加成方式为主。此外,以含铑催化剂催化硅氢化反应时,反应程度初期随着反应时间延长、反应温度升高而加深,但反应5 h后或60℃以上基本不变;增加丙烯腈的量有利于增加反应程度,从而引入较多的氰基,但增加幅度不明显。
Polycarbosilane(PCS) is an important precursor of silicon carbide(SiC) fibers and ceramics.As a precursor for preparing SiC fibers and ceramics,it has several deficiencies,such as low ceramic yield,which affect the properties of final products.Cyano-polycarbosilane,a new SiC precursor,was synthesized by using hydrosilylation addition reaction of PCS and acrylonitrile,which is not easy for hydrosilylation generally.During the synthetic process,rhodium-containing catalyst and 2-methylpropionitrile were used.The ceramic yield of PCSCN would be significantly increased to over 80%,as compared with that of PCS,especially as the rhodium-containing catalyst was used.The molecular structure of PCSCN was analyzed by using IR and NMR,showing that the hydrosilylation reaction was mainly α-addition.In addition,the degree of hydrosilylation increased with increasing reaction time and reaction temperature at the initial stage,but remained almost unchanged when the time was longer than 5 h or the temperature was higher than 60 ℃.Increasing the content of acrylonitrile would lead to increase in the degree of reaction and thus more cyano groups were introduced in PCSCN,but the magnitude was low.
作者
谢富成
陈豆
莫高明
何流
黄庆
XIE Fucheng;CHEN Dou;MO Gaoming;HE Liu;HUANG Qing(Ningbo Institute of Material Technology and Engineering,Engineering Laboratory of Advanced Energy Materials,Ningbo 315201,Zhejiang,China;College of Chemical Engineering,Zhejiang University of Technology,Hangzhou 310014,Zhejiang,China)
出处
《陶瓷学报》
CAS
北大核心
2024年第1期109-116,共8页
Journal of Ceramics
基金
浙江省自然科学基金(LY21B040003)
宁波市“3315”创新计划资助(2018A-03-A)。
关键词
丙烯腈
聚碳硅烷
硅氢化
陶瓷产率
acrylonitrile
polycarbosilane
hydrosilylation
ceramic yield
