The effect of heat setting on the structure and mechanical properties of poly(ethylene terephthalate) fiber. IV. Tensile properties other than modulus and their dependence on structure

The stress‐strain characteristics of poly(ethylene terephthalate) fibers, heat set under different conditions have been studied under tension, and mechanical properties such as tenacity, yield point, elongation at break, and work of rupture are presented and discussed. An attempt has been made to correlate these mechanical properties with structural parameters. The orientation of the molecules in the fiber and the size and distribution of the crystallites emerge as important factors controlling the tensile properties.