氟硅改性聚氨酯-羟基丙烯酸酯复合乳液的制备与性能研究

Synthesis and Properties of Waterborne Polyurethane-Acrylate Composite Emulsions Modified by F-Si

利用无皂乳液聚合法制备了含端羟基聚醚改性硅油(THPDMS)的氟硅双改性聚氨酯-丙烯酸酯复合乳液(WPUA),系统研究了甲基丙烯酸十二氟庚酯(DFHMA)、甲基丙烯酸羟乙酯(HEMA)含量对乳液及胶膜性能的影响。结果表明,随着DFHMA和HEMA含量的增加,复合乳液的粒径及分散系数增大;WPUA中引入氟单体DFHMA能明显地降低涂层的表面能,降低幅度达40%左右;当F含量增至5.08%时,表面能降低趋势渐缓,水、油的接触角最高达118.0°和78.2°,涂层表现出明显的双疏性;随着HEMA和交联剂N3300含量增加,胶膜交联密度增大,吸水率逐渐降低,最低可达5.54%,同时胶膜的拉伸强度明显增强,当w(HEMA)由0增加至4.66%时,拉伸强度由15.7 MPa提升至36.0 MPa,获得高强度的WPUA胶膜;此外,HEMA和DFHMA引入WPUA中,增加了涂层的热稳定性,其初始分解温度提高10℃左右。

F-Si modified waterborne polyurethane-acrylate （WPUA） composite emulsions containing THPDMS were successfully synthesized via a soap-free emulsion polymerization method. The influence of DFHMA content and hydroxyethyl methacrylate （HEMA） content on the properties of the emulsions and film thereof were systematically discussed. The results showed that with the increase of DFHMA and HEMA, the particle size and the dispersion coefficient of the emulsion increased. The addition of fluoride monomer DFHMA could obviously reduce the surface energy of the film nearly by 40%, and the water and oL-bromonaphthalene contact angle were 118.0° and 78.2°, respectively when the F content was 5.08%, wherein the film showed evidently amphiphobic properties. With the increase of the HEMA and crosslinker （N3300） , the crosslinking density increased while the water absorption decreased even down to 5.54%. In addition, the tensile strength increased from 15.7 MPa to 36. 0 MPa as the HEMA amount increased from 0 to 4. 66 wt.%. The thermal stability was enhanced owing to the incorporation of HEMA and DFHMA into WPUA, and the initial decomposition ternperature increased form 0 ℃ to 10℃.