Synthesis of cationic poly [N-isopropylacrylamide] microgel latexes using a thiol-containing monomer, vinylbenzylisothiouronium chloride

Monodisperse thermosensitive latex particles have been prepared by radical- initiated precipitation polymerization of N-isopropylacrylamide (NIPAM), N, N-methylenebisacrylamide (MBA), and using 2,2'-Azobis(2-amidinopropane) chl oride (V50) as an initiator and vinylbenzylisothiouronium chloride (VBIC) a s a thiol-containing monomer. The final latexes were characterized with res pect to monomer conversion, polymer composition, particle size and size dis tribution. Particular attention was paid to the effect of VBIC concentratio n on the synthesis and colloidal properties of the resulting latexes.