THERMAL AND MECHANICAL-PROPERTIES OF POLY(ETHER URETHANE) MODIFIED BY COPOLYAMIDE SEGMENTS

Thermoplastic polyurethane elastomers (TPUs) from diol-terminated poly(tetramethylene glycol) (PTMG), 1,4-butanediol (BD), and 4,4'-methylenediphenyl diisocyanate (MDI) were modified by copolymerizing diamine-terminated nylon-6/6,6 copolyamide oligomer. In TPUs modified by the copolyamide segment, the hard segment showed decreased crystallinity and melting point depression as the content of copolyamide segment was increased, which is probably due to mixing and strong interaction between copolyamide and hard segments. As some of the hard segments were replaced by copolyamide segments, the crystallinity of PTMG segments increased. This suggests that the copolyamide-PTMG segment interaction is weaker than the interaction between hard and PTMG segments. Tensile properties of TPUs are discussed based on the thermal properties.