Synthesis and properties of IPDI-based TPU and HMDI-based TPU

Isophorone diisocyanate(IPDI)-based thermoplastic polyurethane(TPU) and dicyclohexylmethane diisocyanate(HMDI)-based TPU, which used the mixtures of tetrahydrofuran-ethylene oxide copolyether(PET) and poly(ethylene-propylene adipate)(PEPA) as soft segment and 1, 4-butanediol (BDO) as chain extender, were prepared by bulk polymerization. The experimental techniques utilized were Fourier transform infrared spectrum(FT-IR), differential scanning calorimetry (DSC) and tensile testing to study the properties of the IPDI-based TPU and HMDI-based TPU. The results show that, compared with IPDI-based TPU, HMDI-based TPU has higher tensile strength and Young's modulus its hard segment is more immiscible with the polyester of the soft segment. Also HMDI-based TPU shows better microphase separation and obvious crystalline structures in contrast to IPDI-based TPU.