磷酸酯化苯丙共聚物乳液的合成及防锈性能

以甲基丙烯酸(MAA)为亲水单体、甲基丙烯酸羟丙酯(HPMA)为交联单体、苯乙烯(St)和甲基丙烯酸甲酯(MMA)为硬单体、丙烯酸丁酯(BA)为软单体、2-羟乙基甲基丙烯酸酯磷酸酯(PM-2)为功能单体、十二硫醇为链段调节剂,采用半连续种子乳液聚合法,制备了具有核壳结构的磷酸酯化苯丙防锈乳液(PM-2-SP)。讨论了PM-2用量对PM-2-SP乳液稳定性、胶膜耐水性及漆膜防锈性能的影响。利用DLS、TEM及AFM对PM-2-SP乳液乳胶粒的大小及形貌进行了表征,采用盐水喷雾试验机对漆膜的防腐性进行了测试。结果表明:当PM-2用量为4%(以总单体质量为基准,下同)时,PM-2-SP乳液粒径为135.7 nm,PDI为0.150,且具有核壳结构,稳定性能较好;胶膜表面光滑、致密,且有优异的耐水性能;PM-2-SP漆膜相比纯苯丙漆膜,腐蚀电位上升率为47.16%,可达到–0.391 V,腐蚀电流下降率为94.76%,可达到1.95×10–7 A/cm2。耐盐雾实验证明:核壳结构的苯丙乳液相比均聚的苯丙乳液与金属螯合密度更大,能够展现出优异的防锈性能,耐盐雾时间达到144 h。

Synthesis and anti-rust properties of phosphate esterified styrene-acrylic copolymer emulsion

The phosphorylated styrene-acrylic rust preventive emulsion (PM-2-SP) with core-shell structure was synthesized by semi-continuous seeded emulsion polymerization using methacrylic acid (MAA), hydroxypropyl methacrylate (HPMA) as a crosslinking monomer, styrene (St) and methyl methacrylate (MMA) as hard monomer, butyl acrylate (BA) as Soft monomer, 2-hydroxyethyl methacrylate phosphate (PM-2) as a functional monomer and dodecanethiol as a segment regulator. The effects of the amount of PM-2 on the stability of PM-2-SP emulsion, the water resistance of the PM-2-SP film and the anti-rust properties of the film were studied. Also, the size and morphology of the PM-2-SP emulsion particles were characterized by DLS and TEM. The surface of the film was observed by atomic force microscopy (AFM). The corrosion resistance of the paint film was tested using a salt spray tester. Consequently, the results show that the emulsification of the system and anti-rust performance of the paint film were optimal when the content of PM-2 is 4wt%. The particle size of PM-2-SP emulsion with core-shell structure was 135.7nm and the PDI was as low as 0.150. The film had the smooth and compact surface as well as excellent resistance to water. In addition,The corrosion potential and corrosion current of the film was -0.391V and 1.95E-7(A?cm2), respectively. What''s more, compared with pure styrene-acrylic, the rising rate of corrosion potential and reduction rate of corrosion current of the film was 74.16% and 94.76%, respectively. The salt spray resistance time of the film had extended to 144h.