以丙烯酸为功能性单体的苯丙乳液聚合及其性能研究

Study on Styrene-Acrylic Emulsion Polymerization and Its Performance with Acrylic Acid as Functional Monomer

以苯乙烯与丙烯酸丁酯为共聚单体，丙烯酸为功能性单体，通过半连续种子乳液聚合制备稳定的苯丙乳液。研究表明：当NaHCO，质量配比在0．19％～0．3％时，乳液稳定性好；当丙烯酸质量配比小于2．0时，乳液粒径分布窄，平均粒径为0．18μm，乳液流动性较好，高于2．5时，乳液粒径变大且分布变宽，乳液呈膏状、流动性差；当丙烯酸质量配比增大时，乳液黏度呈逐渐上升趋势；随着氨水质量配比的增加，乳液黏度逐渐增大，但达到一定量后保持不变；随剪切速率增大，乳液呈明显的剪切变稀趋势，说明乳液为假塑性流体。

Stable styrene-acrylic emulsion is prepared through semi-continuous seeded emulsion polymerization with styrene and butyl acrylate as comonomer. The research shows that the emulsion has a good stability when the mass ratio of Na HCO3 is between 0. 19% and 0. 3%; when the mass ratio of acrylic acid is less than 2. 0,the size distribution of emulsion is narrow,the average particle size is 0. 18 μm and the emulsion has a good liquidity; when it is higher than 2. 5,its particle size increases,the size distribution widens and the emulsion has cream shape and poor liquidity; when the mass ratio of acrylic acid increases,emulsion viscosity shows a rising trend; with the increase of ammonia water mass ratio,emulsion viscosity increases gradually and remains unchanged after reaching a certain value; with the increase of shearing rate,the emulsion shows an obvious shear thinning trend,showing that the emulsion is a pseudoplastic fluid.