The effect of crystallinity on fracture and yielding of polyethylenes

The effect of the amount of crystallinity on fracture and yielding of polyethylenes as a function of temperature is reviewed. In particular, the effect of fracture toughness, Kc, at low temperatures is investigated. Generally, Kc increased linearly as density decreased. However, it was found that very low-density polyethylene shows a significant decrease in Kc from this general behaviour.