摘要： 以二甲基乙醇胺(DMEA)同时作为亲水剂和封端剂,开展了封端型聚氨酯阴极电泳乳液的制备。通过傅里叶变换红外光谱(FT-IR)、激光粒径分析、热重分析(TGA)等方法,对聚氨酯(PU)乳液的分子结构、乳液粒径和聚合物解封温度等进行了表征与测试。通过对合成条件的考察发现,选择w(MDEA)=3%、w(DMEA)=5%、封端温度50℃、w(TMP)=2%时,乳液的综合性能较好。乳液的平均粒径为77.50 nm,60 d仍未分层。研究表明DMEA呈现了亲水和封端双功能作用,实现了对亲水基含量可控与调节。所制备的电泳膜的耐水性得到了极大的提升,烘烤后膜的耐水时间达到了158 h。

关键词: 阴极电泳, 聚氨酯, 二甲基乙醇胺, 甲基二乙醇胺, 封端剂

Abstract: The blocked polyurethane cathodic electrophoretic emulsion was prepared by using N, N-Dimethylethanolamine(DMEA) as hydrophilic and blocking agent. The molecular structure, particle size and unblocking temperature of Polyurethane( PU) emulsion were characterized and analyzed by FTIR, laser particle size analyzer, TGA, etc. The synthetic conditions were investigated, and the results showed that when the reaction was performed under the mass fraction of MDEA 3% and DMEA 5%, 2% of TMP at 50 ℃ of blocking temperature, the PU emulsion has good comprehensive properties. The average particle size was 77. 50 nm, and the emulsion showed as separation after 60 days storage. The results indicated that DMEA can provide dual functions of blocking and hydrophile, realizing control and adjustment of the hydrophilic group content. The waterproof of paint film increases from 4 h to 158 h after baking, and water resistant roperty has been greatly improved.

Key words: cathodic electrophoresis, polyurethane, DMEA, MDEA, blocking agent