Synthesis and Application of Waterborne Polyurethane for the Impregnation Process of Microfiber Synthetic Leather

Developing a high-performance waterborne polyurethane for the impregnation process of microfiber synthetic leather is challenging. Conventional waterborne polyurethane has poor alkali resistance at high temperatures. Herein, a series of waterborne polyurethane emulsions were synthesized with varying contents of aminopropyl triethoxysilane (KH550) to improve the high-temperature alkali resistance. The effect of the KH550 concentration on the characteristics of waterborne polyurethane dispersions and films was investigated. Specifically, when the introduction amount of KH550 was 1%, the resulting film exhibited the best overall properties after the reduction process, with a tensile strength of 7.47 MPa and an elongation at a break of 615%. The synthetic leather based on waterborne polyurethane (the amount of KH550 was 1%) exhibited superior properties compared to other synthetic leather. This included a tensile strength (Longitude) of 12.91±0.61 MPa, an elongation at break (Latitude) of 67.34%, a tearing strength (Latitude) of 50.39 N/mm, and a softness of 6.54 mm.