Relationship Between Structure and Properties of Waterborne Polyurethane

A series of waterborne polyurethanes(WPU) were prepared by using polyester glycol(PHA),polyether glycol(N-210、 N-220),castor oil(C.O.),toluene diisocyanate(TDI) and dimethoxypropionic acid(DMPA) as key raw materials and the WPU based on N-220 polyether was modified with organosilicone,organofluorine and hydroxyl-terminated polybutadiene(HTPB) rubber respectively. The effects of soft segment types(N-210、N-220、PHA),crosslink and modification on water resistance,mechanical properties and touch feel of WPU film were investigated by infrared spectroscopy,water adsorption measurement,electronic tensile tester and contact angle measurement. It is found that water resistance and tensile strength of WPU based on PHA are better than those of WPU based on N-210 or N-220,and water resistance and tensile strength of film can be increased by suitable crosslink. The water resistance and surface properties of WPU film can be improved by modification with organosilicone or organofluorine,and the flexibility and mechanical properties of WPU film can be improved by modification with HTPB rubber.