PVC／ABS共混物的热稳定性

Thermal Stability of PVC/ABS Blends

通过熔融共混的方法制备了不同配比的聚氯乙烯(PVC)/丙烯腈-丁二烯-苯乙烯(ABS)共混物,采用热失重法和刚果红试纸法对共混物的热稳定性进行了研究。热失重分析发现,共混物第一阶段失重的起始失重温度T01和最大失重速率时温度T1m都随着ABS接枝共聚物含量的增加向低温方向移动,ABS的加入促进了PVC的降解;刚果红试纸法分析发现PVC/ABS共混物的静态热稳定时间比PVC的长;透射电镜观察发现ABS接枝共聚物的加入改善了PVC的加工流动性,提高了稳定剂的分散性和效率,这是共混物稳定时间变长的主要原因。

Blends of polyvinylchloride （PVC） and acrylonitrile-butadiene-styrene （ABS） with different ratio were prepared by melt blending, the thermal stability of blends was investigated by thermogravimetric analysis and congo red method. Thermogravimetrie analysis shows that the onset temperature of the first degradation step （ T1^0 ） and the temperature at the maximal rate of degradation in the first step of degradation decreases with the increase of ABS grafting eopolymer content. Congo red method shows that the stability time of blends is longer than PVC; TEM ananlysis shows that the main reason why the stability time of blends is longer than PVC is that ABS grafting copolymer can improve processability of PVC and the dispersion of stabilizer.