含氟丙烯酸酯共聚物结晶与涂膜表面润湿性能研究

以全氟辛基乙基甲基丙烯酸酯(FMA)分别和不同侧碳链长度(烷烃链长n=4,8,12,16,18)的丙烯酸酯为原料,合成一系列含氟丙烯酸酯共聚物。用红外光谱仪(FT-IR)和多功能光电子能谱仪(XPS)对共聚物化学结构与涂膜表面化学成分进行表征,结合表面接触角测试仪测定相应涂膜表面接触角并分析了其表面自由能;同时也用示差扫描量热法(DSC),X射线衍射(XRD)和偏光显微镜(POM)对含氟丙烯酸酯共聚物的结晶行为进行分析比较。结果表明,当非氟单体的烷烃链长n=4、8、12时,聚合物在常温下各向同性,不具有结晶性;当n=16、18时在常温下即可结晶,得到近晶A相的层状纹影织构。特别是当n=16时,烷烃侧链排列更紧密,聚合物的结晶具有更好协同作用,表现出优异的结晶规整性和低表面能,从而提高了聚合物涂膜的疏水疏油稳定性。

Study on Crystallization and Surface Properties of Fluorinated Acrylate Copolymers

A series of fluorinated acrylate copolymers were synthesized by using monomers of perfluoroalkylethyl methylacrylate and acrylate with various length of side chain(n=4,8,12,16 and 18,respectively) as raw materials.The chemical structure and surface chemical composition of the prepared copolymer coatings were characterized by infrared spectroscopy(FT-IR) and X-ray photoelectron spectroscopy(XPS).Combining with the contact angle test,the corresponding contact angles of the coatings were measured,and their surface energy were analyzed.The crystallization of fluorinated acrylate copolymers were studied by differential scanning calorimetry(DSC),X-ray diffractometer(XRD) and polarizing microscopy(POM) for further analyzing the influence of different lengths of side chains on the water-and oil-repellent surface.The results show that the copolymers remain isotropic and have no crystallizability under room temperature when the acrylate’s side chain length n=4,8 and 12;whereas when n=16 and 18,the crystallization can occur and the schlieren texture of layered smectic A phase can be obtained.Especially,when n=16,the alkyl side chains are more closely arranged and have a better synergy effect on the crystallization of fluorine-containing polymers,which indicates that the copolymer has excellent crystalline regularity and low surface energy,thus improving the stability of its water-and oil-repellence.