The facile and effective approach for fabricating polyurethane gradient materials with significant damping properties.

Polyurethane is the main matrix material of polymer damping materials, but the damping temperature range is narrow, the effective damping temperature range does not match the working temperature of the material, and the elastic modulus is sensitive to temperature during glass transition, which is not conducive to safe use in a wide temperature range. In this paper, the polyurethane gradient material with the hard segment content continuously changing along the length direction was designed and prepared by the reaction injection method. Dynamic mechanical analysis (DMA) shows that the gradient structure greatly influences the comprehensive damping performance of polyurethane. While maintaining no significant decrease in mechanical properties, the gradient material extends the effective damping temperature range (TR) from 40.7°C (−32.3 ~ 8.4°C) for component A and 66.6°C (59.5 ~ 126.1°C) for component B to 139.5°C (−20.6 ~ 118.9°C). At the same time, the damping peak remains high (0.48), which is close to the higher damping peak of the B component of 0.56. The elastic modulus (E′) decreases slowly with the increase in temperature, which can better ensure the safety of the material. [ABSTRACT FROM AUTHOR]