聚氨酯-丙烯酸酯杂化乳液结构与性能的影响

Effects of the Structure and Properties of Polyurethane-acrylic Hybrid Emulsion

以聚四氢呋喃醚二醇(PTMG)、异氟尔酮二异氰酸酯(IPDI)、亲水单体二羟甲基丙酸(DMPA),乙二胺为主要原料,制备了稳定的水性聚氨酯乳液。然后以苯乙烯(St)、丙烯酸丁酯(BA)为单体,过硫酸钾为引发剂,在不外加乳化剂的条件下,运用物理共混、化学复合和化学共聚三种方法对该水性聚氨酯乳液进行改性研究。用FTIR技术对聚氨酯-丙烯酸酯杂化乳液的结构进行了对比与表征;通过粘度测定、粒度分析、力学性能和耐水性能测试、DSC分析,研究了不同改性方法对乳液及其胶膜性能的影响。结果表明,化学共聚的改性方法对原水性聚氨酯的耐水性的改良效果最好,能够得到稳定且综合性能较优的聚氨酯-丙烯酸酯杂化乳液。

Aqueous polyurethane emulsion was prepared with polyoxytetramethylene glycol（PTMG） ,isophorone diiso- cyanate（IPDI）, dimethylol propionic acid （DMPA） and ethylene diamine（EDA） as primary materials. With potassium persulfate（K2 S2 O8） as initiator, styrene（St） and butyl acrylate（BA） were used as monomer introduced to the waterborne polyurethane dispersions by soapfree emulsion polymerization modified method. By different means, including mechanical blend, chemical blend and chemical copolymerization, three types of polyurethane-acrylic emulsion were prepared respectively signed as PU＋PA, PUA＇, PUA and studied. FTIR was used to demonstrate characteristics of PUA emulsion. Performance of the emulsion and film based on different modified methods was studied by means of rotational viscosimeter, Autosizer ,tensile tester and DSC. The results show that water-resistance property of PU greatly increased by chemical copolymerization modified method, and obtained stable PUA hybrid emulsion with excellent integrated properties.