PVC/MBS/EVA共混物的制备及其抗紫外光老化性能

摘要

Poly(vinyl chloride)(PVC)/methyl methacrylate-butadiene-styrene(MBS)/ethylene-vinyl acetate(EVA)blends were prepared via melt blending method. The contents of carbonyl group and conjugated double bonds in the blend films with different compositions were investigated before and after ultraviolet(UV)-irradiation. The properties of the films before and after UV-irradiation were also characterized. The results show that the simultaneous addition of MBS and EVA as impact modifier helps to improve the anti-UV property of PVC. The yellowing factor and the change of carbonyl index of the blends containing MBS of3.0 phr and EVA of 2.0 phr decrease after UV-irradiation, which are lower than those of the blends only containing MBS of5.0 phr. The decrease rate of yield stress of the blends containing MBS of4.0 phr and EVA of1.0 phr is the smallest after UV-irradiation among all blends. The tensile impact strength of PVC/MBS binary blends are similar with that of PVC/MBS/EVA ternary blends.%采用熔融共混法制备了聚氯乙烯(PVC)/甲基丙烯酸甲酯-丁二烯-苯乙烯三元共聚物(MBS)/乙烯-乙酸乙烯共聚物(EVA)共混物.研究了不同配方共混物薄膜经紫外光老化前后的羰基、共轭双键含量变化,并对共混物经紫外光老化前后的性能进行了表征.结果表明:同时使用MBS和EVA作为抗冲改性剂可以有效提高PVC的抗紫外光老化性能;与单独加入5.0 phr MBS相比,加入3.0 phr MBS和2.0 phr EVA的共混物经紫外光老化前后的羰基指数变化值降低,变黄因数降低;加入4.0 phr MBS和1.0 phr EVA时,共混物经紫外光老化后的屈服应力降低率最小;PVC/MBS和PVC/MBS/EVA共混物薄膜的拉伸冲击性能相差不大.