聚氨酯-氟化聚丙烯酸酯复合乳液的合成

Synthesis of Polyurethane-Poly(Fluorinated Acrylate)Hybrid Latex

首先制备了聚氨酯(PU)种子乳液,再以甲基丙烯酸十二氟庚酯和丙烯酸酯为单体,通过单体滴加法和单体预乳化法两种不同的乳液聚合方法制备了聚氨酯-氟化聚丙烯酸酯(FPUA)复合乳液。采用傅里叶变换红外光谱对FPUA复合乳胶膜的表面结构进行表征,利用激光粒径仪对FPUA复合乳液的粒子形态进行分析,探讨了引发剂种类对FPUA复合乳胶膜耐水性的影响、氟含量对FPUA复合乳胶膜与水接触角的影响和在不同制备工艺条件下含氟单体对FPUA复合乳液粒径及其分布的影响。实验结果表明,含氟单体成功接入了大分子链中;与单体滴加法相比,单体预乳化法制备的FPUA复合乳液的聚合稳定性更好,粒径更小、分布更均匀;与水溶性引发剂相比,采用油溶性引发剂制得的FPUA复合乳胶膜的吸水率更低;含氟单体的引入增大了FPUA复合乳胶膜与水的接触角。对两种聚合工艺的成核机理也进行了初步探讨。

Polyurethane-poly （ fluorinated acrylate） （FPUA） hybrid latices were synthesized from preprepared polyurethane seed latex, dodecafluoroheptyl methacrylate（DFMA） and acrylate monomers by monomer pre-emulsification and monomer dropping methods separately. The particle size and its distribution of the latices were characterized by means of laser light scattering instrument, and surface structures of their films were characterized by means of F-FIR. Effects of initiator types on water absorptions of the films and effects of mass fractions of fluorine on contact angle were discussed. By different preparation methods, influences of dodecafluoroheptyl methacrylate content on particle size and its distribution of FPUA hybrid latices were also discussed. Fluorinated monomer is incorporated into polymer chain successfully, and latex particles prepared by monomer pre-emulsification method are smaller and narrower in particle size distribution than that prepared by monomer dropping method. Compared with water soluble initiator, FPUA film of hybrid latex initiated by oil soluble initiator is low in water absorption. The incorporation of DFMA increased contact angle of FPUA film. Mechanisms of core-forming of two methods were also discussed.