新型双组分室温自交联共聚物乳液体系的研究

Study on Novel Two-Component Copolymer Latices Self-Crosslinked under Ambient Temperature

用马来酸酐和乙二胺合成了含有双键的伯胺化合物(UPA),并用其与丙烯酸系单体进行乳液共聚合制备了双组分室温固化涂料的第一组分。研究了乳化剂种类和UPA用量对聚合稳定性的影响,结果表明,若采用p-壬基酚聚氧化乙烯醚硫酸钠为乳化剂,且UPA用量低于单体总量2.5%(wt)时,可以制得稳定的UPA/丙烯酸酯共聚物乳液。通过对乳液聚合物的红外光谱分析表明,UPA与丙烯酸酯发生了共聚反应。将乙二醇二缩水甘油醚乳化形成水乳液,作为水乳型涂料的第二组分。将两种乳液复合后在室温下干燥成膜,通过对聚合物涂膜的DSC及力学性能的测试表明,双组分体系在成膜过程中发生了交联反应,而未加环氧化合物的单组分聚合物乳液成膜时则不发生交联。研究了不同UPA含量对涂膜拉伸强度的影响,结果表明,在适量UPA用量时可获得最高的涂膜拉伸强度。

An unsaturated primary amine (UPA) was synthesized by using maleic anhydride and ethylene diamine. The UPA-acrylate copolymer latex was prepared and was used as the first component of a novel ambient curable two-component coating. The effects of UPA dosage and kinds of emulsifiers on polymerization stability were investigated. It shows that if sodium p-nonylphenol polyethylene oxide sulfate is used as emulsifier and the UPA dosage is less than 2.5%(wt) of the total amount of monomers, the stable copolymer emulsion of UPA and acrylic monomers can be obtained. The FT-IR analysis for emulsion polymer indicates that UPA can successfully copolymerize with acrylic monomers under given conditions. In addition, ethylene glycol diglycidyl ether aqueous emulsion was used as the second component of the two-component coating. These two components were blended with a certain ratio to obtain a composite emulsion, which was dried to form film under ambient temperature. The film properties were determined by DSC and mechanical tester. The results show that from the composite emulsion the crosslinking film is formed, and no crosslinking occurs if the film is formed by the UPA-acrylate copolymer latex only. With appropriate UFA dosage, the optimal tensile property of the crosslinking film can be achieved.