丙烯酰胺反相细乳液聚合

采用反相细乳液法,以白油为连续相,失水山梨醇单油酸酯/聚氧乙烯失水山梨醇单油酸酯为乳化剂,一种聚合物型乳化剂(聚异丁烯琥珀酸酯与山梨醇油酸酯的混合物)作为助稳定剂,通过正交实验确立了基本乳液体系,考察了微乳化工艺中转速变化、乳化剂体系组成、浓度及单体含量对聚合产物稳定性的影响,并研究了不同单体浓度和聚合时间等聚合工艺对微球粒径及分布的影响。结果表明,复合乳化剂含量为3.0%,转速为10 000 r/min下乳化20 min,在单体浓度55%,亲水疏水平衡值(HLB值)为5.5,采用氧化还原引发体系,聚合时间为6 h时,可以得到固含量35%以上、粒径数百纳米的长期稳定的亚微米级聚丙烯酰胺微球乳液。

Inverse Miniemulsion Polymerization of Acrylamide

Using inverse miniemulsion polymerization, a basic emulsion system with white oil as continuous phase, single sorbitan oleate/polyoxyethylene sorbitan oleate as emulsifier, a polymeric emulsifier (a mixture of polyisobutylene succinic acid ester and sorbitan oleate) as the co-stabilizer was established through the orthogonal experiment. The effects of rotational speed in miniemulsification process, composition, concentration and monomer content of emulsifier system on the stability of the product were investigated. The effects of different polymerization process such as monomer concentration and polymerization time on the particle size and distribution of microspheres were also studied. The results showed that long-term stable sub-micron emulsion grade polyacrylamide microspheres with the particle size of hundreds of nanometer and solid content over 35% were obtained under the conditions of composite emulsifier content 3.0%, emulsion for 20 min at the rotational speed of 10 000 r/min, the monomer concentration 55%, HLB value 5.5 and polymerization time 6 h using redox initiator system.