Preparation and Properties of Epoxy resin Modified Waterborne Polyurethane

The 4,4-diphenyl methane diisocyanate(MDI), polyethylene glycol (PEG)and epoxy resin(EP-44 and EP-51) were selected to prepare series of water polyurethane modified by epoxy resin(EWPU) by using chain extender, catalyst, and neutralizer. The influence of such factors as the R (NCO/OH), the contents of DMPA and epoxy resin on the performance of emulsion and film were discussed in details. The results shows that when R was 1.7, DMPA content was 7%, epoxy resin content was 8%, the EWPU emulsion appears brilliantly and shows great stability, it was measured that the water absorption, tensile strength and breaking elongation of the film are respectively 8.41%, 15.52Wa and 318%. Moreover, the comprehensive performance of the WPU modified by E-44 is better than that modified by E-51. According to the FTIR analysis, the EP has been successfully introduced to the waterborne polyurethane molecular chain.