含疏水侧链聚氨酯表面活性剂的制备及其乳液聚合应用研究

Preparation of polyurethane surfactants with hydrophobic side chains and their application in emulsion polymerization

以异佛尔酮二异氰酸酯、二羟甲基丙酸和单硬脂酸甘油酯为主要原料,通过改变原料配比制备一系列含疏水侧链聚氨酯表面活性剂。采用FT-IR和~1H NMR对产物的结构进行了表征。以单体质量5%的聚氨酯表面活性剂制备了固含量(质量分数)为35%的聚甲基丙烯酸甲酯-co-聚丙烯酸丁酯乳液,研究了预聚物n(-NCO)/n(-OH)对表面活性和乳液聚合应用的影响。结果表明,当预聚物n(-NCO)/n(-OH)=1.07时,含疏水侧链聚氨酯表面活性剂水溶液具有最低表面张力值33.24 mN/m。该聚氨酯表面活性剂用于制备聚丙烯酸酯乳液可得到核壳结构乳胶粒子,当预聚物n(-NCO)/n(-OH)=1.11时,制备得到的乳胶粒子最小,直径约为75 nm。

A series of polyurethane surfactants with hydrophobic side chains （WPU） were synthesized by changing the ratio of the reactants and using isophorone diisocyanate, dimethylolpropionic acid and glyceryl monostearate as main starting materials. Structure of the product was characterized by FF - IR and 1H NMR. Poly- （methyl methacrylate -co- butyl acrylate） emulsion with 35% （mass fraction） solid content was prepared with the polyurethane surfactants （5 % vs. mass of overall monomers）. The effects on surface activity and emulsion polymerization application of the ratio n （ -NCO）/n（-OH） of the pre -polymerized material were studied. Results show that the lowest surface tension of polyurethane solution achieves 33.24 mN/m when the ratio n （ -NCO）/n （-OH） is 1.07. The structure of polyacrylate emulsion particulates prepared using polyurethane surfactants is shell- core type. When the ratio n（ -NCO）/n （-OH） is 1.11, the smallest particulates can be obtained, and their diameter is about 75 nm.