【摘要】 以甲苯二异氰酸酯(TDI)、自制聚酯二元醇为主要原料合成了水性聚氨酯分散体(WPUD),研究了投料方式、反应温度和反应时间、中和方式、乳化温度等工艺参数对NCO含量及WPUD性能的影响。结果表明,采用两步投料法,第一步温度控制在65~70℃、反应1 h,第二步温度控制在70~75℃、反应3 h;采用前中和工艺、乳化时水温控制在20~30℃,有利于形成平均粒径小、粘度低、稳定性好的WPUD,且涂膜具有良好的耐水性和硬度。更多还原

【Abstract】 A stable waterborne polyurethane dispersion(WPUD)was prepared with toluene diisocyanate and homemade polyester polyols as major materials.The influence of reaction temperature and reaction time on the NCO content in prepolymer was studied,and the effect of factors such as the material casting way,neutralizing method and emulsifying temperature on the properties of WPUD was investigated.As the results indicated,polyols and all the small molecule polyol chain extenders were casted in two steps with reaction at 65～70 ℃ for 1 h initially and 70～75 ℃ for 3 h subsequently.The WPUD with small average particle size,low viscosity,good stability was formed when using neutralization first and emulsifying process at 20~30 ℃ water temperature.The dry film had fine water resistance and hardness.更多还原