阳离子无皂含氟丙烯酸酯的合成与表面性能

Preparation and Surface Property of Cationic Emulsifier-Free Fluorinated Polyacrylates

在合成甲基丙烯酸全氟辛酰氧基乙酯（FA）基础上，用半连续法制备了无皂阳离子含氟丙烯酸酯乳液。当乳液的粒径在100～200nm、ζ电位大于40mV时，乳液较稳定。阳离子亲水单体甲基丙烯酰氧乙基三甲基氯化铵（DMC）在含氟丙烯酸酯中质量分数为0．10～0．18、固含量小于20％时乳液的稳定性好，且随DMC含量的增加稳定性提高；含氟丙烯酸酯乳胶膜的附着力与耐磨性好，乳胶膜的透湿率随DMC的增加而增加。随热处理温度的提高，膜表面自由能下降；经160℃热处理后膜发生了交联，表面自由能为18mN／m，与聚四氟乙烯（PTFE）的表面能相近，DMC含量对膜表面自由能影响不大。XPS分析也表明膜表面氟含量随热处理温度的提高而增加。

Perfluoro octylacyloxyethyl methacrylate was synthesized and used in copolymerization with acrylates. The cationic emulsifier-free emulsions was produced by semicontinuing feed. The cationic emulsion was stable when the particle size was in the range of 100-200 nm in diameter, and the Zeta potential of the emulsion was more than 40 mV. Meanwhile, the emulsion was also steady when the solid content was less than 20% and the content of hydrophilic monomer, methacrylacyloxyethyl trimethyl ammonium chloride （DMC）, in copolymer was in 10% ～18 %, and the stability of the emulsion was increased with the addition of DMC. The fluorinated polyacrylates film was of good adhesion and abrasion-resistant, and the water vapor transfer rate of the film was increased with the DMC content increasing. The heat process of the fluorinated polyacrylates film was effective to improve the surface property of the film. The surface free energy of the fluorinated polyacrylates film was declined with increase of the post heated temperature. The surface free energy of the film post heated at 160 ℃, above curing temperature, was 18 mN/m. This result is similar to that of the surface free energy of PTFE. Furthermore, the water and oil-repellent of the film was not influenced by the variation of the hydrophilic monomer content. XPS analysis elucidated that the fluorine content of the film surface increased with enhancement of post heated temperature.