Abstract 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.
