Waterborne Polyurethane Modified with the Hydroxy Silicone Oil for Improving its Thermal, Water Resistance, and Mechanical Properties

Abstract

Hydroxy silicone oil were employed to modify waterborne polyurethane (WPU) by copolymerization reaction. Their structures and properties of Si-WPU were characterized by FTIR, DLS, TEM, TG-DSC, XPS, SEM, AFM and so on, respectively. The results showed that the WPU was successfully modified with hydroxy silicone oil. The surface roughness of the Si-WPU film was significantly improved. The Si-WPU film of the initial decomposition temperature was increased by 62–70°C, the glass transition temperature (Tg) was enhanced by about 60°C, the crosslinking density of the WPU and the tensile strength gradually were also significantly enhanced. The performance of WPU modified with 25000 molecular weight hydroxyl silicone oil(13%,w/w) is by far the best, and the tensile strength properties of the Si-WPU film were significantly enhanced by 2.63MPa. The contact angles of Si-WPU film were improved by 93.95°, 98.67°, and 103.95°, respectively. The water absorption rates were enhanced by 4.17%, 5.21%, and 7.41%, respectively. The corresponding surface energy was also reduced to as low as 13%. It is shown that water resistance, heat resistance, and the microphase separation of the Si-WPU was notablely enhanced, respectively.