电子束辐照含铍聚碳硅烷制备含铍碳化硅纤维  

Synthesis of Silicon Carbide Fiber Containing Beryllium from Polyberylliumocarbosilane Using Electron Beam Irradiation

作　　者：朱文华 岳建岭[1,2] 黄小忠 王春齐[1,2] 胡思闽 王畅[1,2] ZHU Wen-hua;YUE Jian-ling;HUANG Xiao-zhong;WANG Chun-qi;HU Si-min;WANG Chang(School of Aeronautics and Astronautics,Central South University,Changsha 410083,China;Key Laboratory for Advanced Fibers and Composites of Hunan Province,Changsha 410083,China)

机构地区：[1]中南大学航空航天学院,长沙410083 [2]新型特种纤维及其复合材料湖南省重点实验室,长沙410083

出　　处：《材料工程》2018年第12期54-60,共7页Journal of Materials Engineering

基　　金：中南大学创新驱动计划项目(2016CXS006);中南大学研究生自主探索创新项目(2017zzts026)

摘　　要：以含铍聚碳硅烷(PBeCS)为原料,在N2∶O2的流量比为200∶1的气氛下用电子加速器对PBeCS先驱丝进行辐照交联,然后在N2下高温烧结制备含铍碳化硅(SiC)纤维。研究了辐照剂量对先驱丝的化学结构、凝胶含量、含氧量及烧成SiC纤维抗拉强度的影响。结果表明:在有氧的气氛下辐照交联主要是Si—H与O2反应生成Si—OH,然后Si—OH发生脱水缩合反应生成Si—O—Si,Si—H与Si—CH3生成Si—CH2—Si;1250℃烧成制得的含铍碳化硅纤维具有光滑的表面,形成了β-SiC晶型,纤维的氧的原子分数低于5%,C/Si比接近1∶1,纤维的平均强度为1.8GPa,平均弹性模量为179GPa。Polyberylliumocarbosilane（PBeCS）precursor fibers were irradiated using electron beam in an atmosphere with N 2∶O 2 rate of 200∶1,They were then pyrolyzed at high temperature under nitrogen to give silicon carbide fiber containing beryllium（SiC（Be））.The effect of irradiation dose on the chemical structure,gel content,oxygen content,and tensile strength was studied.The results show that Si—H bonds in the molecular structure of PBeCS react with oxygen in the electron beam irradiation under low oxygen partial pressure bombarding to get Si—OH groups,and then Si—OH groups undergo dehydration condensation reactions to produce Si—O—Si linkage,Si—H and Si—CH 3 decompose and polymerize to produce Si—CH 2—Si linkage,resulting in cross-linking.SiC（Be）fibers prepared at 1250℃ have smooth and dense surface.XRD curve reveals that β-SiC microcrystals are formed in the fibers.The atom fraction of oxygen of the fiber is less than 5%,and the molar ratio of C to Si is close to 1∶1,and the average tensile strength and tensile modulus are 1.8 GPa and 179 GPa,respectively.

关 键 词：含铍聚碳硅烷 电子束辐照 交联 含铍碳化硅纤维 

分 类 号：TQ343[化学工程—化纤工业]