Study on the Solvent-free Synthesis and Properties of Waterborne Polyurethane

A series of waterborne polyurethane(WPU)with high ureido group content were prepared by the solvent-free method using polyetheramine D2000, polypropylene glycol (PPG) 2000, isophorone diisocyanate (IPDI) and dimethylolpropionic acid (DMPA) as the main raw materials. The effects of synthesis route and D2000 content on the viscosity of the prepolymer and the property of the resulting WPU were investigated. The results demonstrated that the WPU obtained by the simultaneous addition of D2000 and PPG2000 and post-addition of catalyst had the lowest prepolymer viscosity and the best comprehensive performance.Meanwhile, comparing with WPU without D2000, the tensile strength, 100% modulus, peel strength and solvent resistance of WPU containing 60% D2000 were increased by 39.8%, 25.5% and 51.8%, respectively, while its swelling ratio and elongation at break were decreased by 52.6% and31.3%, respectively. The present effort may provide guidance for the solvent-free synthesis of WPU and the application of polyetheramines in the modification of WPU.