超声聚合.pdf

Available online at Ultrasonics Sonochemistry 15 (2008) 314–319 /locate/ultsonch High purity nanolatex prepared by ultrasonically irradiated emulsion polymerization Yuanyuan Zheng, Ya Cao *, Guangqin Pan State Key Laboratory of Polymer Materials Engineering, Polymer Research Institute of Sichuan University, Chengdu 610065, China Received 10 January 2007; received in revised form 26 March 2007; accepted 27 April 2007 Available online 13 May 2007 Abstract Ultrasonically initiated emulsion copolymerization of styrene and a cationic polymerizable surfactant (methacryloxyethyl dodecydim- ethyl ammonium bromide, C12N+) was successfully employed to prepare high purity copolymer nanolatex. C12N+ can play the roles of an emulsifier, an initiator, and a comonomer at the same time. It has an excellent initiation efficiency and reactivity. The rate of copo- lymerization 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, 1H NMR and surface tension tests proved almost all surfmers had copoly- merized with styrene when the C12N+ concentration was more than 0.030 g/mL, indicating high purity nanolatex without residual emul- sifiers was obtained. 2007 Elsevier B.V. All rights reserved. Keywords: Nanolatex; Polymerizable surfactant; Ultrasonic irradiation; Emulsion polymerization; Polystyrene 1. Introduction property, good solvent resistance, high glos