PHMS为反应性助稳定剂的苯乙烯细乳液聚合

Styrene Miniemulsion Using Hydrogen-Containing Polysiloxane as Reactive Costabilizer

以含氢聚硅氧烷(PHMS)为反应性助稳定剂,研究苯乙烯(St)细乳液聚合。表征了细乳液聚合产物的结构,探讨了PHMS与St接枝共聚反应机理,考察了不同体系聚合产物接枝量、接枝产物中PHMS的含量以及不同乳液聚合反应稳定性和乳胶耐盐稳定性。通过红外和核磁分析结果表明,除St均聚反应外,PHMS通过游离基加成反应与St生成了接枝共聚物。细乳液体系中,PHMS用量由5%质量分率增加到20%,聚合产物接枝量和接枝产物中PHMS质量百分比先增大后降低。当PHMS质量分率为10%时,聚合产物接枝量和接枝产物中PHMS质量百分比出现峰值,分别为73.35%和8.46%。与普通乳液聚合反应相比,细乳液聚合过程中凝胶量减少,细乳液聚合产物接枝量和接枝产物中PHMS质量分率的增加,乳胶耐盐稳定性增强。

The hydrogen-containing polysiloxane （PHMS） was used as reactive costabilizer in styrene （St） miniemulsion polymerization. The structure of St mirtiemulsion, the graft-copolymerization mechanism between PHMS and St, the content of graft polymer and the content of PHMS in graft polymer were investigated by FTIR and 1H-NMR. The polymerization stability in different systems and salt tolerance of PSt latexes were discussed. Results showed that the graft-copolymer between PHMS and St was obtained in miniemulsion polymerization. With improved PHMS concentration from 5 % to 20 %, the grafted degree and the mass percent of PHMS in graft polymer occured the peak value. The peak value of grafted degree and mass percent of PHMS in graft polymer were 73.35% and 8.46 % when PHMS concentration in miniemulsion was 10%. Following the improvement of the graft degree and the content of PHMS in graft polymer, the gel produced in miniemulsion was decreased and the salt tolerance of PSt latexes were improved.