苯丙乳液聚合中粒径及稳定性的影响因素研究

Study on influence factors of particle size and stability in styrene-acrylate emulsion polymerization

以辛基酚聚氧乙烯醚(OP-10)和十二烷基硫酸钠(SDS)为乳化剂、过硫酸铵(APS)为引发剂和碳酸氢钠为缓冲剂,采用种子乳液聚合法合成了苯丙乳液,并探讨了各因素对乳液粒径和聚合稳定性的影响。研究结果表明:聚合温度升高虽会提高单体转化率,但也会降低乳液的聚合稳定性;当m(SDS)∶m(OP-10)=2∶1、w(打底乳化剂)=30%(相对于总乳化剂质量而言)、w(引发剂)=0.6%和w(缓冲剂)=0.3%(均相对于总单体质量而言)时,乳液的聚合稳定性相对较好;总乳化剂含量和打底单体含量是粒径的主要影响因素,乳液粒径随前者含量增加而下降,随后者含量增加而增大。

With polyoxyethylene octyl phenol ether （OP-10） and sodium dodecyl sulfate （SDS） as emulsifiers, ammonium persulfate （APS） as initiator, sodium bicarbonate as buffer agent, the styrene- acrylate emulsion was synthesized by seed emulsion polymerization, and the influences of various factors on particle size and polymerization stability of emulsion were discussed. The research results showed that the monomer conversion rate was increased but polymerization stability of emulsion was reduced with increasing polymerization temperature. The polymerization stability of emulsion was relatively better when mass ratio of m （SDS） ： m （OP- 10） was 2： 1, mass fraction of pre-added emulsifier was 30% in total emulsifier, mass fractions of initiator and buffer agent were 0.6% and 0.3% respectively in total monomers. The contents of total emulsifier and pre-added monomer were main factors that affect the particle size, the particle size of emulsion was decreased with increasing content of the former but was increased with increasing content of the latter.