title: Radical generation process studies of the cationic surfactants in ultrasonically irradiated emulsion polymerization.
abstract: Without any chemical initiators added, ultrasonically irradiated emulsion copolymerization of styrene and a cationic polymerizable surfactant (methacryloxyethyl dodecydimethyl ammonium bromide, C(12)N(+)) was successfully employed to prepare copolymer nanolatexes. Compared with the conventional ionic surfactants, C(12)N(+) has much higher initiation efficiency and C(12)N(+) system exhibits shorter induction period, much higher styrene conversions and polymerization rate R(p) in short reaction time. A radical trapping experiment and gas chromatograph-mass spectrograph analysis proved that under ultrasonic irradiation, C(12)N(+) undergoes bond scission between the two alkyl and ionic group, where both C-N bonds are weak along the chain, thereby producing much more original radicals to initiate the emulsion polymerization.
authors.affiliation: State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China. Electronic address: caoya44@hotmail.com.
authors.forename: Ya
authors.initials: Y
authors.lastname: Cao
authors.affiliation: State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
authors.forename: Yuanyuan
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China.
authors.forename: Guangqin
authors.initials: G
authors.lastname: Pan
mesh_terms: D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D004655:Emulsions; D005609:Free Radicals / Q000737:chemistry* / Q000528:radiation effects*; D008401:Gas Chromatography-Mass Spectrometry; D007202:Indicators and Reagents; D013058:Mass Spectrometry; D010316:Particle Size; D011108:Polymers / Q000138:chemical synthesis; D013501:Surface-Active Agents / Q000737:chemistry* / Q000528:radiation effects*; D014465:Ultrasonics