封闭型聚氨酯-环氧树脂复合乳液的合成及其防腐性能研究  

Synthesis of Blocked Polyurethane- Epoxy Composite Emulsion with Good Anticorrosive Performance

作　　者：龚立祝 张旭东[1] 王月[1] 张林芳[1] 朱可可[1] 

机构地区：[1]湖南大学化学化工学院,长沙410082

出　　处：《涂料工业》2015年第5期12-17,共6页Paint & Coatings Industry

摘　　要：采用二乙醇胺对双酚A型环氧树脂进行开环,再以甲乙酮肟为封闭剂,对聚氨酯预聚体的端-NCO基进行部分封闭,再结合开环后的环氧树脂,合成了一种稳定性良好、防腐性能优异的封闭型聚氨酯-环氧树脂复合乳液.研究了环氧树脂开环剂、聚氨酯预聚体的封闭程度以及环氧树脂用量对乳液和涂膜性能的影响,通过电化学方法和浸泡腐蚀实验研究了涂膜的防腐性能.结果表明：开环后的环氧树脂能显著提高乳液的稳定性,而耐腐蚀性变化不大;聚氨酯预聚体封闭程度为40％～43％时聚合物的交联度合适,乳液性能优异;随着环氧树脂用量增加,乳液粒径先减小后增大,涂膜防腐性能逐渐提高,且远优于非封闭型聚氨酯-环氧树脂成膜体系;环氧树脂用量可达24％左右.Combined with the ring-opening reaction of diethanolamine and bisphenol A epoxy resin, a blocked polyurethane-epoxy composite emulsion with good stability and anticorro- sive property has been prepared using MEKO as blocked agent. The effects of the ring-opening agent, the blocked ratio of polyurethane prepolymer and the dosage of epoxy resin on property of the emulsion and cured film thereof are studied. Furthermore, anticorrosive property of the film is investigated by electrochemical methods and immersion tests. Experimental results show that the ring-opening reaction of epoxy resins by diethanolamine improves the stability of the emul- sions obviously, but anticorrosive behavior of the films isn＇t affected. The emulsion has excellent performance when the blocked radio of polyurethane prepolymer is 40%- 43%. With the increase of epoxy resin content, the particle size of emulsion decreases firstly and then increases, moreo- ver, the film shows better anticorrosive performance than the unblocked PU-epoxy based film. The dosage of epoxy resin can reach up to 24wt.%.

关 键 词：聚氨酯-环氧树脂 复合乳液 封闭 防腐性能 

分 类 号：TQ635.2[化学工程—精细化工]