丙烯酸酯/聚氨酯三层核壳复合乳液的合成与表征

Synthesis and characterization of acrylate/waterborne polyurethane three-layers shell-core hybrid latexes

以自制的聚酯多元醇（PPMBA）、甲苯二异氰酸酯（TDI）、1,6-六亚甲基二异氰酸酯（HDI）、二羟甲基丙酸（DMPA）合成聚氨酯预聚体,再用丙烯酸酯类单体代替有机溶剂对预聚体降黏,封端预聚体后中和分散乳化得包含丙烯酸酯类单体的聚氨酯乳液.向乳液中加入引发剂引发自由基聚合得到复合乳液,最后再加入乙烯基类单体及引发剂合成三层核壳结构的聚丙烯酸酯/聚氨酯复合乳液.研究表明,二异氰酸酯的-NCO与聚酯多元醇中的-OH的物质的量之比（R值）为1.6~4之间时,随R值增加,乳液稳定性增强;DMPA含量在4%~7%的范围内,随DMPA含量的降低,乳胶膜的耐水性提高.通过红外光谱对所合成聚酯多元醇及复合乳液结构进行表征.

Polyurethane prepolymer was synthesized with polyester polyol made by myself,toluene-2,4-diisocyanate,hexmethylene-1,6-diisocyanate,2,2-bis（hydroxymethyl）propionic acid,and then acrylate monomer replaced organic solvent to reduce viscosity of polyurethane prepolymer.After blocking,neutralizing,dispersing and emulsifying,polyurethane emulsion including acrylate monomer was obtained.Next,after adding initiator and initiating radical polymerization,composite emulsion was obtained.Finally,three-layers shell-core structure polyacrylate/polyurethane composite emulsion was obtained after adding vinyl monomers,initiator and initiating.Experiments indicated that,while the initial molar ratio of the-NCO and-OH（R value）range from 4to 1.6,the steady of emulsion was improved with the increasing of R value.In addition,the less contents of DMPA（DMPA with mass fraction in the range of4%~7%）let to the greater water resistance of latex film.The structures of polyester polyol and composite emulsion were characterized by infrared spectroscopy（IR）.