Thermal stability of PVC/ABS blends

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. Thermogravimetric analysis shows that the onset temperature of the first degradation step (T10) and the temperature at the maximal rate of degradation in the first step of degradation decreases with the increase of ABS grafting copolymer 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.