Effects of hard segment contents on cryogenic viscoelasticities of gap-based polyurethane elastomers

摘要

Gap-based polyurethane elastomer (GAPE) was synthesized through meltprepolymerization method using 1,4-butanediol (BDO) as chain extender. Dynamic mechanical analysis (DMA) was applied to research the dynamic mechanical properties of GAPE.Then storage modulus, loss modulus and dissipation factor were obtained. Based on the time-temperature superposition theory, master curves with frequency spanning more than ten several orders of magnitude range were obtained. The constants C_(18) and C_(2g) of WLF equation were calculated. The dynamic mechanical properties parameters, activation energy and fragility parameter of GAPE were obtained. The results show that the ETPE having 35% hard segment exhibits better mechanical properties (σb=14.6MPa, εb=460%) and lower Tg (-29.6°C).