紫外光老化线型低密度聚乙烯复合纤维的微观形态及力学性能研究  

Study on Micromorphology and Mechanical Properties of Linear Low Density Polyethylene by UV Photoaging

作　　者：严龙飞 公维光[1] 孟鑫[1] 林珩[1] 郑柏存[1] 李青圃 YAN Long-fei;GONG Wei-guang;MENG Xin;LIN Heng;ZHENG Bai-cun;LI Qing-pu(East China University of Science and Technology,Shanghai 200237,China)

机构地区：[1]华东理工大学,上海200237

出　　处：《塑料工业》2020年第S01期141-147,共7页China Plastics Industry

基　　金：上海市体育运动材料研发平台专项项目(19DZ2293200)。

摘　　要：通过熔融纺丝法制备了含不同种类光稳定剂的线型低密度聚乙烯(LLDPE)复合纤维,研究了在紫外光加速老化下LLDPE纤维的力学性能与微观形态的关系。通过测试老化时间对LLDPE纤维力学性能的影响,确定了最佳配方,并采用差示扫描量热仪(DSC)、X射线衍射(XRD)、高温凝胶渗透色谱(GPC)、全反射红外光谱(ATR)等方法表征了紫外光老化对LLDPE纤维微观形态的影响。结果表明,随着老化时间的延长,空白LLDPE的力学性能下降明显,而添加了光稳定剂的复合纤维则先上升后缓慢下降,特别是复配了光稳定剂944和326的纤维,800 h时其拉伸强度和断裂伸长率仅分别下降了13.70%和11.38%,结晶行为、分子量和羰基指数测试结果也出现了相同的变化趋势。复配光稳定剂通过对游离态自由基的捕捉作用和特定波长紫外光的吸收作用可以减少O2对LLDPE内部晶体结构的破坏,并延缓LLDPE大分子链的降解,使纤维在老化后仍保留较好的力学性能,同时,由于退火和二次结晶的作用,这些纤维的力学性能均出现了先上升后下降的变化。Linear low density polyethylene(LLDPE)composite fibers with different kinds of light stabilizers were prepared by melt spinning method,and then the relationship of their micromorphology and mechanical properties were investigated by accelerating ultraviolet aging.By testing the effect of aging time on mechanical properties of LLDPE fiber,the optimal formula was determined.The influence of ultraviolet(UV)aging on micromorphology was studied by differential scanning calorimetry(DSC),X-ray diffraction(XRD),high temperature gel permeation chromatography(GPC),total reflection infrared spectroscopy(ATR)and other methods.The results show that the increase of aging time could decrease the mechanical properties of blank LLDPE.And the addition of light stabilizer could increase the mechanical properties firstly and then decrease.After aging for 800 h,the tensile strength and elongation at break of the samples blended by 944 and 326 could decrease 13.70%and 11.38%,respectively.The results of crystallization behavior,molecular weight and carbonyl index also show the same trend.The compound light stabilizer can reduce the damage of O2 to the internal crystal structure of LLDPE,through the capture of free radicals and the absorption of ultraviolet light at specific wavelengths,and delaying the degradation of LLDPE macromolecular chains,therefore,the sample could retain good mechanical properties after aging.At the same time,the mechanical properties of these samples could increase first and then decrease due to the effects of annealing and secondary crystallization.

关 键 词：线型低密度聚乙烯 紫外光老化 光稳定剂 微观形态 力学性能 

分 类 号：TQ325.12[化学工程—合成树脂塑料工业]