采用原位乳液聚合法,在可聚合阴离子乳化剂/非离子乳化剂复配体系下,以γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)改性的纳米SiO2、甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、丙烯酸(AA)等为核相组成,以MMA、BA及甲基丙烯酸十二氟庚酯(DFMA)为壳相单体,合成纳米SiO2/含氟聚丙烯酸酯复合乳液。考察了纳米SiO2和DFMA用量对乳液聚合过程及乳胶膜表面疏水性能的影响。通过透射电子显微镜(TEM)、差示扫描量热仪(DSC)、热重(TG)、接触角(CA)及X射线光电子能谱(XPS)等方法表征乳液的结构及形态、乳胶膜的表面性能和耐热性能。结果表明,纳米SiO2/含氟聚丙烯酸酯共聚物复合粒子呈现出明显的核壳结构,乳胶膜中氟元素呈梯度分布;纳米SiO2粒子的引入不仅提高了乳胶膜的疏水性,也在一定程度上改善了聚合物膜的耐热性能。
The core-shell nano-SiO2/fluorinated polyacrylate emulsion containing fluorine in the shell was synthesized via in-situ emulsion polymerization in the presence of reactive anionic emulsifier and nonionic emulsifier,with the core phase consisting of nano-SiO2 modified by γ-(methacryloxy)propyltrimethoxy silane(KH-570),methyl methacrylate(MMA),butyl acrylate(BA)and acrylic acid(AA),and the shell phase monomer consisting of methyl methacrylate(MMA),butyl acrylate(BA)and dodecafluoroheptyl methacrylate(DFMA).The influence of the amount of nano-SiO2 and fluorine-containing monomer(DFMA)on the emulsion polymerization process and surface hydrophobic properties of the latex films was discussed.The nano-SiO2/fluorinated polyacrylate emulsion and its films were characterized by transmission electron microscopy(TEM),differential scanning calorimetry(DSC),thermogravimetry(TG),contact angle(CA)and X-ray photoelectron spectroscopy(XPS)analysis.The results showed that the resultant particles had core-shell structure and a gradient distribution of fluorine in the latex films was formed.The core-shell nano-SiO2/fluorinated polyacrylate latex film showed higher hydrophobicity and thermal stability comparing with fluorinated polyacrylate latex film due to the addition of nano-SiO2.