纳米二氧化硅改性水性聚氨酯

Waterborne Polyurethane Modified by Nano-SiO_2

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2 h;扩链反应的反应温度40℃,反应时间1 h;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 75 ℃ and reaction time was 2 hours, the reaction temperature for chain extending was 40℃ 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.