蒙脱土改性核壳乳液的制备及其成膜防水性能

Preparation of Montmorillonite Modified Core/Shell Emulsions and Its Film Waterproof

以甲基丙烯酸甲酯、丙烯酸正丁酯、甲基丙烯酸为聚合单体,有机蒙脱土(OMMT)为改性剂,采用原位插层聚合制备了一系列软核硬壳型核壳乳液,并研究了OMMT的添加方式及添加量对乳液粒径、凝聚率、固含量、稳定性以及乳液膜的防水性能的影响。结果表明,OMMT的添加量和添加方式对乳液粒径、凝聚率、固含量、稳定性等基本性能影响不大;当有机蒙脱土被添加在核壳乳液的核层时,乳液膜的防水性能最佳,原因是核层的玻璃化温度较低,层状OMMT在其中分散更好,增大了水分子扩散的路径;随着OMMT含量的增加,乳胶膜防水性能呈现先增长后下降的趋势,这说明少量OMMT可以分散于膜中提高防水性,而过量的OMMT易团聚反而降低了乳胶膜的防水性能。

A series of soft-core/hard-shell emulsions were synthesized by in-situ intercalative polymerization,using methyl methacrylate,butylcyanoacrylate,and methyl acrylic as monomers and the organic montmorillonite（OMMT）as a modifier. The effects of the adding mode and mass fraction of OMMT on the particle size ofemulsion,agglomerate rate,solid content,stability and waterproof of emulsion films were studied. The resultsshow that the adding mode and mass fraction of OMMT have little impact on the particle size of emulsion,agglomerate rate,solid content and stability. The waterproof of emulsion film is best when the OMMT is added inthe core layer,because the glass transition temperature of core layer is lower,and the OMMT have gooddispersion in soft core and increase the average diffusion distance of water in film. As the mass fraction oforganic montmorillonite increasing,the waterproof of emulsion film increases at first and then decreases. Thisresult shows that the small mass fraction of OMMT can be well-dispersed in emulsion and improves thewaterproof property of film;however,the large mass fraction of OMMT is inclined to agglomerate in emulsion andreduces the waterproof property.