Study On The Synthesis And Modification Of Aqueous Polyurethane

Different factors such as temperature,hard segment and–COOH content,ratio of–NCO/-OH,the effect of EDA addition sequence influence on the properties of aqueous polyurethane and their films have been studied.Two type of hybrid emulsions of PUDS,GDPUA have been prepared when polyurethane were modified by acrylate and silicone respectively.1. The reaction temperature was one of important factor in the proess of prepolymer reaction. queous polyurethane main-chain and the acting force between the main-chain changed with R value,hard segment and -COOH% content,Feed Way of chain extender,These changes all influenced viscosity,particle size,stability,solid content and mechanical properties of the waterborne polyurethane. The results show that according to first adding 50% of EDA content,then adding water,finally adding rest of EDA.stable WPU emulsion with high solid content (about 43%) and film with excellent properties were prepared when prepolymer reaction temperature was 65～80℃, -COOH% content was 2%,R value was 1.4.2.Effect of the amount of polyether type amino-silicone oil on the aqueous polyurethane emulsion and its films modified by silicone were discussed.The results show that the stability and adhesion of the modified emulsion were well;When the quality ratio of polyether type amino-silicone oil was 2% and 3%,This product showed excellent complex properties.3.The influence of initiator,temperature,amount of polyacrylate,ratio of MMA/BA on the properties of obtained polyurethane-polyacrylate (GDPUA) and its films.Compared with means,including mechanical blend,chemical copoly -merization,two types of polyurethane-acrylic emulsion were prepared respectively signed as PUPA,PUA.Performance of the emulsions and films based on different modified methods was studied by means of TEM,DSC,TG.The results show that GDPUA emulsion form well-proportioned core-shell emulsion,and show well -compatibility,its particle size decreases;meanwhile,GDPUA film present higher thermostability;the film with excellent properties is prepared when the quality ratio of MMA/BA was 3:2,Polyacrylate content was 40%.