聚丙烯腈预氧纤维/硅橡胶烧蚀防热材料的制备及其性能  

Preparation and properties of polyacrylonitrile pre-oxidized fiber/silicone rubber ablation composites

作　　者：杨芮 刘磊春 史胜 许海建 陈文旗[1] 陈一[1] YANG Rui;LIU Leichun;SHI Sheng;XU Haijian;CHEN Wenqi;CHEN Yi(Research and Development Center,Shanghai Spaceflight Precision Machinery Research Institute,Shanghai 201699,China)

机构地区：[1]上海航天精密机械研究所研发中心,上海201699

出　　处：《材料工程》2024年第8期200-211,共12页Journal of Materials Engineering

基　　金：上海市青年科技启明星计划项目(21QA1403900)。

摘　　要：聚丙烯腈预氧纤维(PANOF)作为一种低成本、高性能阻燃纤维,在航空航天用热防护材料中极具应用前景。选用丙酮和硅烷偶联剂KH570依次对市售PANOF进行除油纯化和表面改性,得到了预处理PANOF(t-PANOF)。通过扫描电子显微镜(SEM)、傅里叶红外光谱(FT-IR)和X光电子能谱(XPS)对预处理前后的PANOF进行了表征,比较了纤维形态结构及其与硅橡胶(SR)界面性能的变化。研究了t-PANOF对SR力学性能和热性能的影响,并考察了在助成瓷剂(CFA)作用下,CFA/t-PANOF/SR三元复合材料的烧蚀响应行为。结果表明:经过预处理,纤维与橡胶的界面黏合水平得到了显著改善,t-PANOF/SR复合材料的拉伸断裂强度也随之提高。但是随t-PANOF含量的增加,复合材料的综合力学性能呈现出先上升后下降的趋势,纤维最佳用量为5~10份。t-PANOF增强骨架的构筑有助于改善SR在高温富氧环境下的维形能力以及CFA/t-PANOF/SR复合材料的烧蚀表现。在2 MW/m~2高温氧化气流下,CFA/t-PANOF/SR复合材料表面生成了以纤维骨架为主体结构的抗氧化陶瓷层,对应线烧蚀率和质量烧蚀率仅为0.02 mm/s和0.02 g/s,有望成为新一代空天飞行器的烧蚀防热材料。Polyacrylonitrile pre-oxidized fiber(PANOF)is an emerging flame retardant material with low cost and high performance,showing a promising application potential as thermal protection materials in the aerospace field.Pretreated PANOF(t-PANOF)was obtained by the process of oil removing with acetone and surface modification using silane coupling agent KH570 in turn.Scanning electron microscopy(SEM),Fourier transform infrared spectroscopy(FT-IR)and X-ray photoelectron spectroscopy(XPS)were employed to figure out the changes of morphology and chemical structure of the fibers before and after pretreatment and their interfacial properties with silicone rubber(SR).Effects of t-PANOF on the mechanical and thermal performances of SR were further investigated.With the presence of ceramic forming agent(CFA),the ablation responsive behaviors of CFA/t-PANOF/SR ternary composites were researched as well.The results show that the level of interfacial adhesion between fibers and rubber is significantly enhanced contributed from the pretreatment of PANOF,and the tensile strength of the composites is improved accordingly.However,with the increasing content of t-PANOF,the comprehensive mechanical properties of t-PANOF/SR composites show the trend that increase first and then decrease,indicating that the optimal dosage of the fibers is 5 to 10 phr.t-PANOF skeleton helps to not only enhance the dimensional stability of SR in high temperature and oxygen-rich environment,but also improve the ablation performance of CFA/t-PANOF/SR composites.The antioxidation ceramic layer with fiber skeleton as the main structure is formed on the surface of CFA/t-PANOF/SR composites under the high temperature aerobic gas with the heat flux density of 2 MW/m2,the corresponding linear and mass ablation rate are only 0.02 mm/s and 0.02 g/s respectively,which is expected to be utilized as an ablation material to satisfy the demands of the new generation of aerospace vehicles.

关 键 词：聚丙烯腈预氧纤维 硅橡胶 界面黏合 烧蚀 抗氧化 

分 类 号：TQ333.93[化学工程—橡胶工业]