Abstract
This article reports the effects of molding temperature on super-structure, mechanical properties, friction, and abrasion of polyurethane elastomers (PUEs). PUEs were prepared from a polyester glycol or polyether glycol (Mn=2000), 4, 4′-diphenylmethane diisocyanate, and a mixture of 1, 4-butanediol and trimethylolpropane as a chain extender. The molding temperature was varied from 110°C to 150°C. Morphology and mechanical properties of these PUEs were studied by means of a DSC, polarizing microscope, Instron tensile tester, Taber abraser, DIN abraser, and Heidon-14 friction tester. In PUEs molded at lower temperatures, phase separation proceeded, and spherulites were observed. These spherulites disappeared with elevating molding temperature in polyester-based PUEs. The abrasion resistances evaluated by DIN abrasion test lowered with a rise in the molding temperature. However, tensile strength was not affected by the molding temperature in polyester-based PUEs, because of the crystallization induced by stretching and reinforcing effect of the hard segment. Friction coefficient lowered with lowering molding temperature.
