Degradation of mechanical properties of polyurethane elastomer coatings under different pavement pollution conditions

The purpose is to reveal the property development laws of polyurethane elastomer coatings for pavement in different polluted environments, and further promote their application in the road field. The ultra high molecular weight polyethylene (UHMWPE) micropowder/polyurethane elastomer (PU) composite coatings and the UHMWPE micropowder/polyvinyl alcohol (PVA) fiber/PU composite coatings were prepared. The basic pavement performances of different elastomer composites formulations were evaluated. Four different pavement polluted environments in practical application, including acid, alkali, salt, and gasoline, were simulated. The degradation laws of mechanical properties such as tensile, tearing, impact, and cushion for polyurethane elastomer coatings at different polluted environments and curing times were studied systematically. The durability of polyurethane elastomer coatings was clarified. The results indicate that the optimal formulation of the composites is determined as "PU+ 3 wt% UHMWPE" based on pavement performances and mechanical properties. The retention rates of mechanical properties for UHMWPE/PU composites after continuous exposure to different polluted environments for 7 days are over 90%. After 30 days of exposure, the decay rates of mechanical strength indicators such as tension and tear are relatively high, about 20 %- 25 %. The decay rate of absorbed energy is relatively low, about 10 %- 15 %.