含氧气氛下电子束辐照聚碳硅烷制备碳化硅纤维  

SYNTHESIS OF SILICON CARBIDE FIBER FROM POLYCARBOSILANE USING ELECTRON BEAM IRRADIATION UNDER LOW OXYGEN PARTIAL PRESSURE

作　　者：童林剑[1] 苏智明[1] 龚朝阳[1] 甘念渝[1] 王周成[2] 陈立富[1] 

机构地区：[1]厦门大学材料学院福建省特种先进材料重点实验室,福建厦门361005 [2]厦门大学化学化工学院,福建厦门361005

出　　处：《硅酸盐学报》2009年第7期1160-1164,共5页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金重点项目(50532010);福建省科技平台建设项目(2006L2003)资助

摘　　要：以聚碳硅烷(polycarbosilane,PCS)为原料,在含氧气(1%)的气氛下用电子束低剂量辐照PCS原丝,然后在惰性气氛下退火实现不熔化处理并烧成制得碳化硅(SiC)纤维。分析了退火温度对辐照后PCS的氧含量、凝胶含量及化学结构的影响,研究了PCS在含氧气氛下辐照及在惰性气氛下退火所发生的化学反应。结果表明:在辐照过程中,主要是Si—H与O2反应生成Si—OH;在退火过程中,主要是Si—OH缩合脱水生成Si—O—Si交联结构。在1250℃烧成制得的SiC纤维呈芯–壳结构,表壳富氧,而芯部氧含量较低。纤维的平均拉伸强度为2.4GPa,平均弹性模量为170.1GPa。Polycarbosilane （PCS） precursor fibers were irradiated using electron beam at low dose and under low oxygen partial pressure. They were then annealed at inert atmosphere, and pyrolyzed at high temperature under nitrogen to give silicon carbide fibers. The chemical reactions occurring during irradiation and annealing were studied. The results show that Si-H bonds in the molecular structure of PCS react with oxygen under electron beam bombarding to get Si-OH groups. During annealing, Si-OH groups undergo dehydration condensation reactions to produce Si-O-Si linkage, resulting in cross-linking. Silicon carbon fibers prepared at 1250℃ have a shell-core structure. The shell is oxygen-rich, and the core is oxygen-deficient. The average tensile strength and tensile modulus are 2.4GPa and 170.1GPa, respectively.

关 键 词：聚碳硅烷 电子束辐照 碳化硅纤维 交联 

分 类 号：TQ343[化学工程—化纤工业]