High purity nanolatex prepared by ultrasonically irradiated emulsion polymerization

Ultrasonically initiated emulsion copolymerization of styrene and a cationic polymerizable surfactant (methacryloxyethyl dodecydimethyl ammonium bromide, C12N+) was successfully employed to prepare high purity copolymer nanolatex. C12N+ can play the roles of ail emulsifier, an initiator, and a comonomer at the same time. It has an excellent initiation efficiency and reactivity. The rate of copolymerization was high and styrene conversion achieved 95% in an hour. Nanoscale latex particles with average diameter 40 nm were obtained easily under ultrasonic irradiation. Results of FTIR, H-1 NMR and surface tension tests proved almost all surfmers had copolymerized with styrene when the C12N+ concentration was more than 0.030 g/mL, indicating high purity nanolatex without residual emulsifiers was obtained. (C) 2007 Elsevier B.V. All rights reserved.