Study On The Synthesis And Performance Of Waterborne Polyurethane Emulsion

Waterborne polyurethane coating is a kind of environment friendly coating,in the process of using,it will not pollute the environment,and is harmless to the human body.Waterbased polyurethane has excellent mechanical properties,good flexibility,wear resistance,ageing resistance and chemical resistance,and waterborne polyurethane are widely used in leather,adhesives and coatings,etc.The research content of this paper are as follows:1.A kind of monomer,which is 2-ethyl-2-oxygen cinnamic acid acyl methyl-1,3 propanediol,was synthesized by ourselvs.A kind of aqueous polyurethane resin was synthesized from 2-ethyl-2-oxygen cinnamic acid acyl methyl-1,3 propanediol,N-methyl diethanolamine,ethylene glycol,polypropylene oxide glycol,diphenyl methane diisocyanate and toluene diisocyanate in toluene solution,and then the aqueous polyurethane emulsion was perpared by the reaction between polyurethane resin and glycolic acid in water.The experimental results showed that the solid content of waterbased polyurethane is lower,and the emulsion is unstable,and the particle size is bigger.Waterborne polyurethane films have poor water resistance.2.The anionic aqueous polyurethane emulsion was synthesized using castor oil,polypropylene oxide glycol,dimethylolpropionic acid,diphenyl methane diisocyanate and triethylamine as raw materials by acetone technology.The storage stability and solvent resistance of the aqueous polyurethane emulsion were studied.The experimental results showed that the content of dimethylolpropionic acid in waterborne polyurethane coating had a greater influence on water resistance,the content of castor oil in waterborne polyurethane had influence on water resistance,acid resistance and alkali resistance.At the curing temperature of 70 ?,the waterborne polyurethane film which the ratio of polypropylene oxide glycol,castor oil and dihydroxy methyl propionate is 0.35:0.65:0.4,has a better water resistance,acid resistance and alkaline resistance.3.The cationic waterborne polyurethane emulsion according to the present paper was produced from castor oil,polypropylene oxide glycol,N-methyl diethanolamine,diphenyl methane diisocyanate and ethanol acid by the acetone process.The storage stability and solvent resistance of aqueous polyurethane emulsion were studied.The experimental results showed that the content of N-methyl diethanolamine in waterborne polyurethane coating had a greater influence on water resistance,the content of castor oil in waterborne polyurethane had influence on water resistance,acid resistance and alkali resistance.At the curing temperature is 80 ?,the water resistance,acid resistance and alkaline resistance of waterborne polyurethane,which the ratio ofpolypropylene oxide glycol,castor oil and N-methyl diethanolamine is 0.4:0.6:0.7,are better.