Tensile properties of PVC at elevated temperatures

Abstract

A series of PVC (polyvinyl chloride) compounds containing 0–100 phr (parts by weight per hundred parts of PVC resin) di-isooctyl phthalate was subjected to tensile testing at temperatures in the range from room temperature to 180°C. It was found that the relationships between elongation at break and stress at break for a range of PVC compounds were almost independent of formulation and strain rate. Stress at break decreased steadily with increasing test temperature, whereas elongation at break revealed a maximum at 80–90°C and a minimum at 130–170°C. This behaviour was attributed to the presence of a network of PVC crystallites, which starts to break down at 90°C. Eventually, there is sufficient destruction of the network to enable viscous flow to occur.

MST/1593