摘要
采用高温干燥箱在230、250、275、300℃下制备了不同老化状态的芳纶Ⅲ样品,并对老化试样进行了单丝拉伸测试及相应的结构分析。结果表明,在实验温度范围内,芳纶Ⅲ的强度保留率随热氧老化时间的延长和温度的升高而降低;TG和IR分析表明,芳纶Ⅲ的化学结构未随热氧老化处理而发生明显改变;通过X射线衍射分析,发现纤维聚集态结构随温度升高发生重排;SEM测试表明,经过热氧老化纤维的断裂方式从劈裂断裂变成了脆性断裂;最后,结合纤维聚集态结构模型,解释了老化前后纤维力学性能下降的原因及原纤劈裂到脆性断裂的机理。
In order to prepare aramid fiber Ⅲ samples under different thermal-oxidative aging conditions,a series of thermal aging experiment was carried out at the temperatures of 230 ℃,250 ℃,270 ℃ and 300 ℃ with the high temperature oven.Single filaments tensile test and relevant structure analysis were implemented with the samples.Results of the single filaments tensile test show that the strength retention of aramid fiber decreases with the time going on as well as the temperature rising up.The TG and IR analysis shows that there＇s nearly no molecular structure change in the thermal-oxidative aging experiment.By wide angle X-ray scattering（WAXS） analysis,it is found that the aggregate structure changes with temperature rising under thermal-oxidative conditions.By the Scanning Electron Microscope（SEM）,it is proved that after thermal-oxidative experiment,the fracture morphology of the filaments changes from bond split failure to the brittle rupture.At last,combined with the model of aggregate structure of the aramid fiber,the reason why the tensile properties drop after thermo-oxidation aging and mechanism of fracture of the fiber was discussed.
出处
《固体火箭技术》
EI
CAS
CSCD
北大核心
2011年第2期247-251,共5页
Journal of Solid Rocket Technology
关键词
芳纶Ⅲ
热氧老化
结构
断裂形貌
aromatic polyamide Ⅲ
thermal aging
structure
fracture morphology
