内绝热层中芳纶中空烧蚀形貌的形成机理研究  

Evolution mechanism of hollow ablation structure of aramid fiber in internal insulation materials

作　　者：高国新[1] 孙静[2] 熊礼龙[1] 郑元锁[1] GAO Guoxin;SUN Jing;XIONG Lilong;ZHENG Yuansuo(School of Chemistry,Xi’an Jiaotong University,Xi’an 710049,China;Xi’an Institute of Space Radio Technology,Xi’an 710100,China)

机构地区：[1]西安交通大学化学学院,西安710049 [2]西安空间无线电技术研究所,西安710100

出　　处：《固体火箭技术》2022年第1期140-145,共6页Journal of Solid Rocket Technology

摘　　要：为揭示柔性内绝热层材料内有机纤维在烧蚀过程中的形貌变化规律和烧蚀机理,分别采用氧乙炔火焰、1000℃高温铁板和热失重加热等不同加热方式,初步探究了不同烧蚀形式下芳纶纤维或腈纶纤维在结炭层内部的形貌演变特征,发现经氧乙炔火焰烧蚀后芳纶增强体系的结炭层内中芳纶炭化纤维呈现中空烧蚀形貌,而腈纶增强体系的结炭层中几乎无纤维状结构出现;相反,采用1000℃高温铁板烧蚀后结炭层中芳纶纤维仍保持其原始实心结构,而腈纶纤维却呈现出中空烧蚀形貌;而慢速的热失重加热方式下,即使被加热到1000℃,两种纤维仍保持其实心结构。因此,芳纶纤维独特的皮芯结构是导致其高温烧蚀形成中空烧蚀形貌的内因,而复合材料中橡胶基体热解气体对纤维皮层的冷却作用和骤然升温的快速加热方式则是导致芳纶纤维形成中空结构的重要外因。The morphology evolution and the ablation mechanism of organic fibers in the flexible internal insulation materials upon high temperature ablation were investigated by using oxyacetylene flame,high-temperature iron plate(~1000℃)and thermogravimetry measurement.The morphological evolution characteristics of aramid fibers or acrylic fibers inside the carbonized layer under different ablation conditions were preliminary studied.The results show that after ablating under oxygen acetylene flame,the carbonized aramid fibers inside the char layer present a hollow ablative structure,whereas no fibrous structure could be detected for the PAN fiber reinforced composites.On the contrary,the carbonized PAN fibers is hollow,the carbonized aramid fibers are still solid in the char layer if ablated by high-temperature(1000℃)iron plate.Both kinds of fibers still maintain solid structure if heated with a slow heating rate.Therefore,the unique skin-core structure of aramid fibers is the intrinsic cause to form the hollow ablation morphology.Meanwhile,the external factors for the hollow structure would be ascribed to the cooling effect of pyrolysis gas on the skin-layer of aramid fibers and the rapid heating mode of sudden temperature rise.

关 键 词：内绝热层材料 芳纶 烧蚀 中空结构 形成机理 

分 类 号：V255[一般工业技术—材料科学与工程]