Initiator Artifacts in the Emulsion and Microemulsion Copolymerization of Partially Water-Soluble Monomers

摘要

The emulsion and microemulsion copolymerizations of partially water-soluble monomers ethylacrylate(EA)and methylmethacrylate(MMA)were studied with the water-soluble initiator KPS and the oil soluble initiator AIBN.On changing from an emulsion to microemulsion system the shift in relative contribution of the different phases involved in particle formation is expected to control the kinetic and colloidal parameters and hence the solid content and latex stability.This has been tested using the water-soluble initiator KPS and the oil-soluble initiator AIBN.The microemulsion system initiated with KPS resulted in a much higher particle size and lower particle stability,whereas the emulsion system initiated with KPS at identical reaction conditions resulted in a stable colloidal polymer particles of very low particle size at a higher solid content.On the contrary,AIBN-initiated microemulsion generated a stable nanolatex as compared to the emulsion system.The copolymers,isolated during the nucleatian stage,were analyzed for their composition using ~1H NMR and for their thermal properties using DSC.