Synthesis and Properties of Micro-crosslinked Poly-propylene Glycol Based Polyurethane Elastomer

Poly-propylene glycol based polyurethane elastomer shows excellent hydrolysis and weather resistance, poor heat resistance and mechanical property. In this work, the prepolymer containing crosslinking center was synthesized by adding pentaerythritol propoxylate into the system of 4,4'-diphenylmethane diisocyanate and poly-propylene glycol. Micro-crosslinked polyurethane elastomer was further synthesized with addition of 1,4-butanediol as the chain extender. The effect of pentaerythritol propoxylate content or crosslinking degree on the heat resistance, mechanical and rheological properties was investigated. It was found that the tensile strength, tear strength, hardness and heat resistance were improved with the addition of pentaerythritol propoxylate. Vicat softening temperature was enhanced from 90℃ of controlled uncrosslinked polyurethane elastomer to 135℃ when the additive amount of pentaerythritol propoxylate was 3% of PPG-1000. The glass-transition temperature, elasticity modulus, viscous modulus and complex viscosity of poly-propylene glycol based polyurethane elastomer were also enhanced. © 2020, Materials Review Magazine. All right reserved.