The Research Of Synthesis And Application Of Organic Silicon Modified Waterborne Polyurethane Coating Agent

In this exxperiment,it selected IPDI,polyethylene glycol 2000,epoxy chloropropane,diethylene triamine,n-butyl amine,epoxy capping agent[1,3-glycidoxypropyl(1,1,3,3-tetramethyl)cyclotetrasiloxane],D4,as the main starting material,First,the issue aims to synthesizing alkylhydroxyl silicone oil;secendly,synthesizing waterborne polyurethane chain extender,obtain a the emulsifying properties of organic silicone modified waterborne polyurethane coating agent.By studying the reactant ratio R,reaction time and temperature impact on the performance of product,the best synthesis process as following:(1)Synthesis of waterborne polyurethane prepolymer: R = 2.4,the initial prepolymer temperature 75℃,initial pre-polymerization time 2h.(2)Waterborne polyurethane chain extender process optimization for: pre polymers with home-made waterborne polyurethane chain extender,R ’ = 1.6,the chain extending temperature 75℃,chain extending time 1.5h,obtain waterborne polyurethane.(3)Alkane hydroxyl silicone oil synthesis process: n(n-butyl amine): n(epoxy capping agent)= 2:1,under the condition of the reaction temperature 70℃ and reaction time is 4h,silicone oil modified end capping agent was prepared.According to a certain proportion to join D4 and catalyst tetramethyl ammonium hydroxide,under the condition of synthesis temperature is 110℃ reaction 2h,obtain alkane hydroxyl silicone oil;(4)Organic silicone modified waterborne polyurethane synthesis process: adding slow waterborne polyurethane molecular to weight of 5000 g/mol of alkane hydroxyl silicone oil(amount of substance ratio of 1:1),under 75 ℃,the modified after 2h,emulsification.Tested by infrared spectrum analysis product bonding effect,and thermo-gravimetric analysis product heat resistance and thermal decomposition.Using the single factor variable method,by changing the homemade coating agent dosage,curing temperature,curing time finishing for cotton fabrics,it is concluded that the best finishing process for coating agent: when finishing cotton fabrics,coating agent dosage of 10g/m2,180 s drying under 80 ℃,140 ℃ baking under the 140 s.Organic silicone modified waterborne polyurethane finishing of coated fabric hydrostatic pressure is 169 mm,softness is 1.89 cm,number of washing up to 20 times.Compared with the commercially available silicone coating agent,homemade organic silicone modified waterborne polyurethane coating agent has better hydrostatic pressure and whiteness,and has excellent washing resistance.And itself has emulsifying performance,belongs to the green environmental protection product.So the coating agent has extensive market prospect.