接枝型耐紫外线老化乙烯-乙酸乙烯酯共聚物的制备及其性能研究

Preparation of the permanent anti-UV-aging ethylene-vinyl acetate copolymer

将4-丙烯氧基,2-羟基二苯甲酮(AHB)作为紫外光吸收剂与乙烯-乙酸乙烯酯共聚物(EVA)以不同比例共混后通过平板硫化机压成1 mm厚的的片材,空气氛围中,以4.4×105 k Gy·h-1的剂量率对其进行辐照,将AHB以化学键方式接枝固定在EVA中。采用GB/T 1040-2006方法考察共混片材的机械性能,FT-IR光谱表征共混膜中AHB的存在,紫外光谱考察紫外线吸收性能,光学显微镜观察片材拉断后的截面形貌。结果表明,随AHB的含量从0 phr增加至2 phr,材料的断裂伸长率从586%上升至772%;同时抗张强度从32.1 MPa下降至22.4 MPa;添加1份(每100份聚合物)紫外吸收剂的EVA抗紫外老化性能显著优于未添加的样品。

4-Allyloxy-2-hydroxybenzophenone（AHB）, the grafting type ultraviolet absorber was blended with EVA by melting extrusion. After mixing, the composites were hot-pressed to sheets with a thickness of 1 mm. And then the sheets were irradiated by electron-beam for 100 kGy at dose rate 4.4 × 10^5 kGy.h^-1. This study focuses on AHB effects on the mechanical properties according to GB/T 1040-2006, and resistance to ultraviolet aging properties of the cable material by FT-IR and UV. The results showed that the breaking elongation of the material increased from 586% to 772%, while the tensile strength decreased simultaneously, from 32.1 MPa to 22.4 MPa, with the raising of AHB content from 0% to 2%. The performance of EVA with 1 phr ultraviolet absorber is significantly superior to the pristine on the mechanical properties under UV- irradiation at different times.