Using A Reactive Surfactant In Ultrasonically Irradiated Emulsion Polymerization To Prepare High Purity Copolymer Nanolatex

In recent years, the preparation of polymeric nanomaterials have attracted much research interest. However, it is difficult to prepare polymer nanoparticles with narrow particle size distribution by conventional emulsion polymerization and the residual initiator and emulsifier have bad effects on latex products. In this paper, ultrasonic irradiation technology and a kind of polymerizable surfactant were used in emulsion polymerization to prepare functional copolymer nanoparticles with high purity and high performance. The surfactant C₁₂N⁺ served as not only a emolsifier but also a initiator in the reactions.A kind of methacrylate cationic reactive surfactant methacryloxyethyl dodecydimethyl ammonium bromide (C₁₂N⁺), which has excellent surface activity and reactivity, was synthesized and used as not only the emulsifier but also the initiator and the comonomer in ultrasonically irradiated emulsion polymerization. A radical trapping experiment and GC-MS analysis confirmed that the free radicals involved in the irradiation process originated from the decomposition of C₁₂N⁺. The initiation mechanism was that under ultrasonic irradiation, C₁₂N⁺ undergoed bond scission between the alkyl and ionic group, where the bonds were weak along the chain, then radicals were originated to initiate the polymerization. Because the ionic group locates in the middle of the molecule, C₁₂N⁺ has two reactive points, the initiation efficiency and reactivity of it is more higher than conventional ionic surfactants. The reaction efficiency of ultrasonically irradiated emulsion polymerization had been improved, and the conversion of styrene...