【摘要】 为提高传统含氟丙烯酸酯乳胶膜表面性能的稳定性,以γ-(甲基丙烯酰氧基)丙基三甲氧基硅烷(MPS)作为可交联单体,采用细乳液聚合法合成了MPS改性的含氟丙烯酸酯共聚物,利用DLS、TEM、IR对聚合物进行表征,研究了MPS对合成乳液的稳定性、涂膜性能和膜表面接触角稳定性的影响。结果表明,细乳液聚合法适合用于对水敏感单体的聚合,合成的纯丙烯酸酯乳胶为球形结构,平均粒径为92 nm,而氟丙乳胶和含3%MPS的含硅氟丙乳胶形成了典型的核壳结构,平均粒径分别增大至107 nm和103 nm,含硅氟丙聚合物中存在Si-O-Si的交联结构。涂膜性能测试表明,MPS的引入增加了共聚物膜的硬度、耐溶剂性和耐水性。接触角测试表明,随MPS用量的增加,乳胶膜对水的初始接触角和动态接触角随时间的降低值均呈先增大后减小的趋势,共聚体系中加入适量MPS,通过含氟链段与MPS链段的协同作用,可显著提高涂膜表面性能的稳定性。更多还原

【Abstract】 Fluoroalkyl moieties in fluorinated acrylate copolymers have extremely low surface tension,which can endow copolymer films good surface properties.Although fluorinated moieties have the tendency to locate at the surface to minimize the surface energy during film formation process,the moieties may re-migrate into the inner layer of the film when the surface is in contact with the polar liquid for a long time.This remigration feature can deteriorate the stability of surface performance of films during application.In order to enhance the surface stability of fluorinated acrylate copolymer,the self-crosslinkable copolymer latex was prepared via miniemulsion polymerization by using γ-methacryloxypropyl trimethoxylsilane( MPS) as a self-crosslinkable monomer.The particle size,morphology and chain structure of the yielding copolymers were characterized by DLS,TEM and IR techniques,and the influence of MPS on the stability of the emulsion,film properties,especially surface property stability of the copolymer were studied.The results showed that the miniemulsion polymerization was suitable for the polymerization of the monomers sensitizing to water.Although the pure acrylate latex formed had spherical structure with an average particle size of 92 nm,the fluorinated and silicon containing fluorinated acrylate copolymer latex had core-shell structure with diameter about 107 nm and 103 nm,respectively.The Si-O-Si structure,indication of crosslinking,was found in the films of silicon containing fluorinated acrylate copolymer.The film performance test indicated that the incorporation of MPS into the copolymer structure could enhance the surface hardness,solvent resistance and water resistance of fluorinated acrylate polymer.The water absorption rate of common acrylate latex film is found to be 16. 0%,however,the absorption rate of the copolymer films reduced to 4. 7%when 5% of MPS was used.The contact angle measurement showed that the initial contact angle( θ) of copolymer films and the value of the △θ( difference of contact angle of initial and for a period) increases first and then decreases with the increase of MPS contents.From the results,it could be concluded that the surface property of fluorinated acrylate polymer can be stabilized by adding appropriate amount of MPS.更多还原