纳米SiO_2/聚氨酯-含氟丙烯酸酯杂化乳液的合成与表征

Synthesis and characterization of nano-SiO_2/polyurethane-fluorinated polyacrylate hybrid emulsion

采用种子乳液聚合法,以聚氨酯(PU)乳液为种子(在聚合过程中为壳相),甲基丙烯酸甲酯(MMA)、丙烯酸丁酯(BA)、甲基丙烯酸十二氟庚酯(DFMA)和γ-甲基丙烯酰氧丙基三甲氧基硅烷(KH-570)改性的纳米SiO2组成的混合物为核相,合成了具有核壳结构的纳米SiO2/聚氨酯-含氟丙烯酸酯(SiO2/FPUA)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性能的影响。通过傅里叶红外光谱(FT-IR)、接触角(CA)、透射电子显微镜(TEM)、热重(TG)、差示扫描量热仪(DSC)和力学性能测试(MPT)等表征乳液的结构形态、乳胶膜的表面性能和综合性能。结果表明:乳胶粒子呈现'反相核壳'结构,以聚丙烯酸酯(PA)相为核,PU相为壳;由于纳米SiO2和DFMA的协同作用,涂膜的疏水性和综合性能得到了较大的提高。

A core-shell type nano-SiO2/polyurethane-fluorinated acrylate （SiO2/FPUA） hybrid emulsion was synthesized by seeded emulsion polymerization using polyurethane （PU） as seed, which served as shell phase in the hybrid emulsion mentioned above, with the core phase consisting of nano-SiO~ modified by γ- （methacryloxy） propyltrimethoxy silane （KH-570）, methyl methacrylate （MMA）, butyl acrylate （BA） and dodecafluoroheptyl methacrylate （DFMA）. The influence of the amount of nano-SiO2 and fluorine-containing monomer （DFMA） on emulsion polymerization process and surface hydrophobic properties of the latex films were discussed. The nano-SiO2/fluorinated polyacrylate emulsion and the latex film were characterized by Fourier transform infrared spectrum （FT-IR）, transmission electron microscopy （TEM）, contact angle （CA）, thermogravimetry （TG）, differential scanning calorimetry （DSC） and mechanical properties test （MPT） analysis. The results indicated that the latex particles showed a ＂reverse core-shell＂ structure, with PA as core and PU as shell, and the hydrophobieity and comprehensive properties of the latex film were greatly improved owing to the synergistic effect of DFMAand nano-Si02.