Ternary Blends to Improve Heat Distortion Temperature and Rheological Properties of PVC

Summary: Binary and ternary blends of PVC mixed with α ‐methylstyrene/acrylonitrile‐butadiene‐styrene copolymer (AMS‐ABS) and ethylene/vinyl acetate/carbon monoxide terpolymer (EVA‐CO) are investigated, with the aim to obtain a new PVC based material with an improved heat distortion temperature and good processability. Dynamic Mechanical Thermal Analysis (DMTA) reveals that ternary PVC/AMS‐ABS/EVA‐CO blends exhibit two glass transition temperatures: the lower T g corresponds to a PVC/EVA‐CO phase and the higher one to a PVC/AMS‐ABS phase. An analysis of PVC respective interactions with AMS‐ABS and EVA‐CO leads to assert that the distribution of PVC in the ternary PVC/AMS‐ABS/EVA‐CO system is basically controlled by the binary immiscible blend composition, taken as Φ AMS‐ABS/Φ EVA‐CO ratio. The inclusion of AMS‐ABS and EVA‐CO to form ternary blends based on PVC, allows to improve heat distortion temperature (owed to the presence of AMS‐ABS), maintaining a low viscosity in the molten state, due to the plasticizing effect of EVA‐CO.Viscosity function obtained at T  = 170 °C from extrusion capillary measurements.