Effects of Hard Segment Contents on Dynamic Mechanical Properties of Gap-based Polyurethane Elastomers

摘要

Gap-based polyurethane elastomer (GAPE) with different hard segment contents are synthesized with 4'4-Diphenylmethane diisocyanate (MDI), 1,4 butylene glycol(BDO) as hard segments and GAP as soft segments. Dynamic mechanical analysis (DMA) is applied to investigated the dynamic mechanical properties and the mechanical properties of GAPE are studied by materials laboratorial instrument. The results show that GAPE-2 with 33 wt% hard segment has better mechanical properties, of which the tensile strength is 11.3MPa and elongation at break is 460.5%. As shown in DMA, T_g of GAPE-2 is -18.4°C, and the low-temperature fragility parameter and activation energy of GAPE-2 are lower, 55.6 and 271.0 KJ·mol~(-1) respectively. Elastomer with good stiffness and flexibility is obtained.