采用聚酯二元醇(聚乙二醇,聚四氢呋喃二醇)、二苯基甲烷二异氰酸酯(MDI)、2,2-二羟甲基丙酸(DMPA)、三羟甲基丙烷(TMP)、三乙胺(TEA)、水为基本原料,用原位聚合法合成了纳米二氧化硅改性水性聚氨酯乳液,讨论了改性纳米二氧化硅加入量、改性剂磷酸盐酯的加入量、NCO/OH量比等因素对乳液性能的影响.研究表明,较佳的合成工艺条件为:制备预聚物时NCO/OH比值为3.5∶1；以DMPA为扩链剂,采用原位聚合的方法,其用量为预聚物质量分数的7.0％；预聚物合成反应温度为75℃,反应时间2h；扩链反应的反应温度40℃,反应时间1h；中和度为80％～100％.在此工艺条件下,合成的纳米二氧化硅改性水性聚氨酯具有良好的稳定性能.%Nano-SiO2 modification of waterborne polyurethane emulsions were synthesized by in-situ polymerization with polyester glycol (PEG,PTMG,982R, JSH-10-P) with 4,4'-diphenylmethane diisocyanate,Dimethylol propionic acid (DMPA),TEA and water as raw materials. The influences of modified Nano-SiO2 dosage, modifier phosphate ester dosage, and NCO/OH molar ratio on the emulsion properties were discussed. The results showed that the optimal conditions of the reactions were as follows: NCO/OH was 3.5:1 for preparing prepolymer, the adding amount of dimethylol-propionic acid as hydrophilic extender was 7.0% of the prepolymer mass, the reaction temperature for preparing prepolymer was about at 751 and reaction time was 2 hours, the reaction temperature for chain extending was 401 and reaction time was 1 hours, the degree of the neutralization was between 80% and 100%. The obtained Nano-SiO2 modification of waterborne polyurethane had good stability under above narrated process conditions.
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