Heat and oxidation resistance of polyurethane

Polyurethane elastomer has good heat resistance in inert gas (such as nitrogen), oxygen resistance and ozone resistance at room temperature, especially polyester type. But high temperature and oxygen can accelerate the aging process of polyurethane. The upper temperature limit of general polyurethane elastomer used continuously in air for a long time is 80-90 ℃, and it can reach

At 120 ℃, the temperature which has a significant effect on thermal oxidation is about 130 ℃. According to its variety, the heat-resistant oxidation performance of polyester type is better than that of polyether type. In the polyester type, the polyelectrolyte type is better than the general polyester type. In polyether type, PTMG type is better than PPG type, and both of them are improved with the increase of elastomer hardness. In addition, the strength of polyurethane elastomer decreased significantly at high temperature. When the temperature is 70-80 ℃, the tear strength is about half reduced. At 110 ℃, the decrease is about 80%. The tensile strength and wear resistance also show similar regularity. However, the high temperature strength of poly - ε - caprolactone elastomer is better.