环境温度对紫外辐照HDPE结构与性能的影响研究

采用元素、XPS、GPC分析，凝胶和力学性能测定，研究了空气中不同环境温度下紫外辐照官能化HDPE的结构、粘着性以及紫外辐照官能化HDPE对HDPE/聚乙烯醇(PVA)体系的增容作用。实验结果表明，提高环境温度可显著提高引入C-O、C(=O)O和C=O等含氧基团的速度。在相同辐照时间下，随环境温度提高，辐照HDPE的分子量下降、分子量分布变宽以及剥离强度提高的幅度增大，并在70℃时产生凝胶。较高环境温度下辐照的HDPE对HDPE/PVA共混体系有较好增容作用，在HDPE/PVA(83/17)体系中加入10%(质量分数)的70℃环境温度下辐照24h的HDPE，共混物的拉伸屈服强度和缺口冲击强度分别从30.8MPa和110J/m提高到34.9MPa和142J/m。

Effect of environmental temperature on chemical structure and properties of ultraviolet irradiated HDPE

The chemical structure and adhesiveness of high-density polyethylene (HDPE), functionalized through ultraviolet irradiation at environmental temperature of 35～70℃ in air, and the compatibilization of the ultraviolet irradiated HDPE in HDPE/polyvinyl alcohol(PVA) fiber blends were investigated by elementary analysis, XPS, GPC, gel measurement and mechanical properties test. The results show that during the ultraviolet irradiation, the oxygen-containing groups, such as C-O, C=O and C(=O) O, are introduced onto the molecular chains of HDPE, and their amount increaes with increasing environmental temperature. After the ultraviolet irradiation, the molecular weight of HDPE decreases and its distribution becomes wider, and the peel strength of the HDPE films increases. Furthermore, their variatio amplitude increases with environmental temperature. A gel appears in HDPE irradiated at environmental temperature of 70℃ for 24 h. The irradiated HDPE behaves as a compatibilizer in HDPE/PVA-fiber, improves the affinity between HDPE and PVA fiber. By adding 10% by weight of HDPE irradiated at environmental temperature of 70℃ for 24 h into HDPE/PVA-fiber(73/17) blends, the yield and notch Izod impact strength of HDPE/PVA-fiber blend (83/17) are incrfeased from 30.8 MPa and 110 J/m to 34.9 MPa and 142 J/m, respectively.