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

Thermoplastic polyurethane elastomers (TPUs) from diol-terminated poly (tetramethylene glycol) (PTMG), 1,4-butanediol (BD), and 4,4'-methylen ediphenyl diisocyanate (MDI) were modified by copolymerizing diamine-t erminated nylon-6/6,6 copolyamide oligomer. In TPUs modified by the co polyamide segment, the hard segment showed decreased crystallinity and melting point depression as the content of copolyamide segment was in creased, which is probably due to mixing and strong interaction betwee n copolyamide and hard segments. As some of the hard segments were rep laced by copolyamide segments, the crystallinity of PTMG segments incr eased. This suggests that the copolyamide-PTMG segment interaction is weaker than the interaction between hard and PTMG segments. Tensile pr operties of TPUs are discussed based on the thermal properties.