二次辐照对交联聚乙烯结构和性能的影响及其应用

Effect of Second Irradiation on Structure and Performance of Crosslinked Polyethylene and Its Application

研究了辐照对高密度聚乙烯(HDPE)、低密度聚乙烯(LDPE)、线型低密度聚乙烯(LLDPE)、乙烯-乙酸乙烯酯共聚物(EVA)及其共混物性能的影响。将辐照交联后的聚合物经扩张定型后再次辐照,考察了二次辐照对交联结构的影响,并利用二次辐照法制备了一种新型热收缩套管产品。结果表明:随着辐照剂量的增加,样品的凝胶含量增大,拉伸强度先增大后减小,而断裂伸长率则逐渐降低;二次辐照后,样品的形变回复率随着辐照剂量的增加显著降低;所制备的热收缩套管两端收缩率大、中间部分收缩率小,实现了同一制品不同部位收缩倍率的可控性,具有良好的应用前景。

The effects of irradiation on properties of high density polyethylene （HDPE）, low density polyethylene （LDPE）, linear low density polyethylene （LLDPE）, ethylene-vinyl acetate copolymer （EVA） and their blends were studied. After the polymer was crosslinked by irradiation, it was expanded and stereotyped, then irradiated another time. The effect of the secondary irradiation on crosslinked structure of the polymer was also investigated, and a kind of new type of heat shrinkable casing product was prepared by utilizing this method. The results show that： with the increase of irradiation dose, the gel content of the samples increases, the tensile strength increases first and then decreases, while the elongation at break reduces gradually; after secondary irradiation, deformation recovery rate of the samples reduces significantly with the increase of irradiation dose. The shrinkage rate of the prepared heat shrinkable tube is large on both ends, and small at the center, that shows the contraction ratio in different location of same product is controllable, and the secondary irradiation method has a good application prospect.