含氟丙烯酸酯乳液高疏水性与低氟含量的平衡探索

Balance of Low Content of Fluorine and High Hydrophobicity of Fluorinated Acrylate Latex Film

为了研究含氟丙烯酸酯乳液涂膜的疏水性与氟含量的平衡关系,以甲基丙烯酸十二氟庚酯(DFHM)为含氟单体,双丙酮丙烯酰胺(DAAM)和己二酸二酰肼(ADH)为交联单体,采用半连续核壳乳液聚合的方法合成了一系列自交联含氟丙烯酸酯共聚物乳液。研究表明:含氟单体含量为12%(即氟含量为6.84%,均以聚合单体的总质量计,下同)时,含氟基团在涂膜表面可以达到饱和,乳液固含量可达38.2%;再添加4%交联单体,涂膜的水接触角为116.6°。当含氟单体含量降为4%(氟含量2.28%)时,通过提高成膜温度或添加成膜助剂,也可使涂膜表面的水接触角达到104.2°,具有较好的疏水性能。

A series of self-crosslinking fluorinated acrylate copolymer latex were prepared via the semi - continuous core - shell emulsion polymerization method from the dodecafluoroheptyl methacrylate（DFHM） as fluorine-containing monomer, diacetone acrylam- ide （DAAM） as crosslinking monomer and adipic dihydrazide （ADH） as crosslinking agent. The hydrophobieity of the prepared latex film affected by the fluorine content was investigated. The effect of DFHM and DAAM on the surface properties of the latex film were investigated, and the structure and the stability of the film were characterized by infrared spectrometer, dif- ferential scanning calorimeter and the contact angle measuring instrument, etc. It was revealed that the surface hydrophobicity and the water resistance of the latex film were enhanced by the introduction of the fluorine-containing monomer and the crosslinking monomer. When the fluo- rine content was 6. 84% based on the total weight of polymerizable monomers wherein the con- tent of the fluorine-containing monomer was 12%, the solid content of the prepared emulsion could be up to 38.2%, and mixed with the crosslinking monomer 4% to form a latex film showing water contact angle 116. 6°. When the content of the fluorine-containing monomerdropped to 4% （i.e., the fluorine content of the system was only 2. 28%）, the water contact angle could also reach to 104.2° by means of higher film-forming temperature and film-form- ing additives, which presented a good hydrophobic performance.