纳米SiO2／丙烯酸酯核壳复合乳液稳定性研究

采用种子乳液聚合技术制备了纳米SiO2/丙烯酸酯核壳复合乳液,研究了氧化硅形态、氧化硅加料方式、乳化剂掺量对核壳复合乳液稳定性的影响.结果表明,氧化硅形态采用胶体二氧化硅,并且预先单体与乳化剂混合对核壳复合乳液的稳定性有利.乳化剂的最佳掺量为单体量的1.8%～3.0%左右,掺量过高,乳胶粒子粒径太小,乳胶粒子表面能过高,且单位乳胶粒表面电荷密度和电位绝对值降低,乳液的稳定性反而有一定程度的下降.

Study of Stability of Nano-SiO2/Polyacrylate Core-Shell Structured Compounded Emulsion

A core-shell structured nano-SiO_2/polyacrylate compounded emulsion was prepared by means of seed emulsion polymerization.Effects of silica dioxide particle morphology,feeding way of silica dioxide and addition of emulsifier on stability of the compounded emulsion were studied.Testing results indicated that,nano-SiO_2 in the form of coloid and premixed with emulsifiers before dripping monomers,was favourable to the stability of core-shell structured compounded emulsion.Optimum addition of emulsifier in emulsion polymerization accounted for about 1.8%-3.0% of total monomer content.Over addition of emulsifier would lead to latex particle size drop,too much increase of surface energy,decrease of surface charge density and Zeta-potential absolute value of latex particle resulting on the contrary in certain decline of stability of the compounded emulsion.