Study on properties of polyurethane elastomers prepared with different hard segment structure

Four different systems of cast polyurethane elastomers were prepared through two-step method by adjusting different isocyanates and amine chain extenders. The blocked polyurethane prepolymer synthesized by the reaction of methyl ethyl ketoxime (MEKO) and the prepolymer weakens the reactivity with the amine chain extender. The mechanical and thermal properties of cast polyurethane prepared by different combinations were analyzed through comparison. The microphase separation of hard and soft segments structure in different systems were observed by using atomic force microscope (AFM). Through dynamic mechanical analysis (DMA), the influence of various structures on the loss factor is discussed. Studying the dynamic endogenous heat of cast polyurethane (CPU) by changing the hard segment structure provides a novel idea for the construction of polyurethane with low-damping structure.