结晶度对聚乙烯热氧老化特性的影响  

Effects of Crystallinity on Degradation Properties of Polyethylene by Thermo-oxidation Aging

作　　者：代军[1] 晏华[1] 郭骏骏 桑练勇 王雪梅[1] 

机构地区：[1]中国人民解放军后勤工程学院化学与材料工程系 [2]73801部队

出　　处：《材料研究学报》2017年第1期41-48,共8页Chinese Journal of Materials Research

基　　金：重庆市研究生科研创新项目(CYS16239)~~

摘　　要：研究了结晶度对聚乙烯在80℃人工热氧老化条件下老化特性的影响,比较分析了不同老化时间其拉伸强度、拉伸模量和冲击强度的变化差异,考察了不同结晶度聚乙烯明度和整体色差变化的差别,采用衰减全反射红外光谱(ATR-FTIR)分析了三种不同结晶度的聚乙烯在老化过程中羰基指数、羟基指数、断链程度、结晶度等微观结构参数的变化趋势。结果表明:在80℃热氧老化环境条件下,随着老化时间的延长,结晶度越高聚乙烯的拉伸性能下降越明显,抗冲击性能的下降越缓慢,明度和整体色差的变化越快,氧化与断链作用更剧烈,其中氧化集中在老化后期,断链主要发生在老化初期,聚乙烯更容易老化。在整个老化周期里,不同结晶度聚乙烯的结晶度均呈现先上升后基本不变的趋势,但是聚乙烯的结晶度越低热老化对其结晶度的影响越大,增大幅度越剧烈。The degradation performance of polyethylene（PE） induced by artificial thermo-oxidation aging at 80℃ was characterized as a function of its crystallinity in terms of the variation of tensile strength, tensile modulus, impact strength and chromatic aberration. The variations of carbonyl index, hydroxyl .index, chain scission and crystallinity of the three as prepared PE with different crystallinities were comparatively examined by attenuated total reflection infrared spectroscopy （ATR-FTIR）. The results show that during thermo-oxidation aging at 80℃, the PE with higher degree of crystallinity experiences significant decrease of tensile property, slow decrease of impact property and faster increase of chromatic aberration. The higher the crystallinity, the molecular chains of the PE prone to breakage in the early aging stage, but its oxidation is more noticeable during the later aging stage. The crystallinity of the PE with different crystallinities trands essentially unchanged after the first rise throughout the aging cycle. But the thermo oxidation-aging has greater influence on the crystallinity, which increases significantly for the PE with lower crystallinity.

关 键 词：有机高分子材料 结晶度 聚乙烯 热氧老化 衰减全反射红外光谱 

分 类 号：O632[理学—高分子化学]