高固含量有机硅改性丙烯酸酯微胶乳的合成及性能

用自制的由阴离子乳化剂十二烷基硫酸钠(SDS)、非离子乳化剂辛基酚聚氧乙烯醚(OP-10)、反应型乳化剂WH-100以及非离子表面润湿剂所组成的混合乳化剂体系,通过半连续单体滴加法合成了平均粒径为59·8nm、粒径分布窄、总固物质量分数达40%的有机硅改性丙烯酸酯微胶乳,并对微胶乳及胶膜的性能进行了研究。结果表明,与间歇预乳化法制备的乳液相比,有机硅改性丙烯酸酯微胶乳的钙离子稳定性较差,其胶膜的吸水率较小,凝胶含量相当;随着乙烯基三乙氧基硅烷(A151)用量的增加,对转化率的影响不明显,微胶乳的钙离子稳定性、胶膜的吸水率下降,乳胶粒子的粒径变大,A151的质量分数宜为4%;随着功能单体甲基丙烯酸-2-羟乙酯(HEMA)用量的增加,微胶乳的钙离子稳定性先提高后降低,而胶膜的吸水率先降低后增大,HEMA的质量分数不宜超过3%。

Synthesis and properties of organic silicone modified acrylate nanolatexes with high solid content

Organic silicone modified acrylate nanolatexes with 59.8 nm of average particle size, narrow size distribution and mass fraction of solid 40% were prepared by semi-continuous monomer addition method with emulsifier mixtures of anionic emulsifier sodium dodeoyl sulfate(SDS), nonionic emulsifier polyoxyethylene octylphenol ether (OP-10), reactive anionic emulsifier WH-100 and nonionic wetting agent. The properties of the nanolatexes and their films were studied. The results showed that the Ca~ 2 stability of the nanolatexes and water absorption of their films prepared by semi-continuous monomer addition method were less than that of latexes prepared by batch pre-emulsification method, but gel contents were approximately equal.The conversions changed slightly, Ca~ 2 stability and water absorption decreased and particle size increased with increasing organic silicone vinyltriethoxysilane (A 151) amount. Optimized mass fraction of organic silicone in recipe was 4%. The Ca~ 2 stability first increased then decreased and water absorption decreased then increased with the increasing functional monomer 2-hydroxyethyl methacrylate(HEMA) amount. The optimized mass fraction of HEMA in recipe was less than 3%.