EVAC和云母对PE-HD基复合交叉膜性能的影响

Effects of EVAC and Mica on Properties of High Density Polyethylene Based Composite Cross Film

以高密度聚乙烯为基体,通过共挤吹塑和聚氨酯胶黏剂黏合制得了一种防水卷材用三层复合交叉膜。利用乙烯-乙酸乙烯酯共聚物(EVAC)和云母母粒对交叉膜进行改性,研究了EVAC含量、云母母粒含量、胶黏剂种类对交叉膜拉伸性能、钉杆撕裂强度及高温处理后尺寸变化率的影响。结果表明,EVAC可有效提高交叉膜的断裂伸长率和钉杆撕裂强度,但增大了交叉膜的尺寸变化率;云母母粒可有效降低交叉膜的尺寸变化率,但对交叉膜的拉伸性能和钉杆撕裂强度有不利影响,云母母粒质量分数不超过9%时,钉杆撕裂强度下降幅度较小。当EVAC质量分数为30%、云母母粒质量分数为9%时,采用牌号为XH50E的聚氨酯胶黏剂,可制得耐钉杆撕裂低尺寸变化率的三层复合交叉膜,其钉杆撕裂强度为63N/mm,尺寸变化率仅为0.4%。

Using high-density polyethylene as the matrix,a three-layer composite cross film for waterproofing sheet was prepared through co-extrusion blow molding and polyurethane adhesive bonding.Ethylene vinyl acetate copolymer(EVAC)and mica master batch were used for modifying the cross film,the effects of EVAC content,mica masterbatch content and adhesive types on the tensile properties,nail shank tear strength and size change rate after high-temperature treatment of the cross films were studied.The results show that EVAC can effectively improve the elongation at break and the nail shank tear strength,but increase the size change rate of the cross film.Mica masterbatch can effectively reduce the size change rate of the cross film,but it has adverse effects on the tensile properties and nail shank tear strength of the cross film,when the mass fraction of mica masterbatch does not exceed 9%,the decrease in nail shank tear strength is relatively small.When the mass fraction of EVAC and mica master‐batch are 30%and 9%respectively,a three-layer composite cross film with low dimensional change rate and resistance to nail shank tearing can be prepared by using polyurethane adhesive with brand XH50E,its nail shank tear strength is 63 N/mm,and the size change rate is only 0.4%.