Phase Change Polyurethane Based on Quadruple HydrogenBonding for Thermal Insulation

A new 2-ureido-4［1H］-pyrimidone (UPy) containing chain extender was adopted to extend the polyurethane prepolymer of hexamethylene diisocyanate (HDI) and polyethylene glycol (PEG). The synthesized polyurethane was characterized by DSC, XRD, viscosity and tensile testing. Results showed that the obtained polyurethane possessed excellent phase change behavior, with phase change enthalpy up to 142 J/g. Meanwhile, its tensile strength was significantly improved when UPy units dimer through a selfcomplementary quadruple hydrogen bond. Compared with polyurethane samples using 1,4-butyl glycol (BDO) and hydroxyethyl ether of resocinol (HER) as chain extender, the tensile strength of this new polyurethane increased by 56% and 19%, respectively.