Cryogenic viscoelasticities of GAP-based polyurethane elastomer

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. Based on the time-temperature superposition theory, the master curves with frequency spanning over ten several orders of magnitude range were obtained. The constants C1g and C2g of WLF equation were calculated. The dynamic mechanical properties parameters, activation energy and fragility parameter of GAPE were obtained. The results show that storage modulus of GAPE-2 having 33% hard segment was 6000 MPa at -50°C. The low-temperature fragility parameter and activation energy of GAPE-2 are 55.6 and 271.0 kJ/mol, respectively.