Akademik Veri Yönetim Sistemi
POLYMER INTERNATIONAL, cilt.56, sa.3, ss.364-370, 2007 (SCI-Expanded)
The inverse microemulsion copolymerization of acrylamide and butyl acrylate initiated by ammonium peroxodisulphate, a water-soluble initiator, and stabilized by anionic emulsifiers sodium bis-2ethylhexylsulfosuccinate and sodium dodecylsulphate (SDS) has been studied. An increase of SDS concentration was observed to increase both the rate of polymerization and the particle size. The average number of radicals per particle ((n) over bar) is much below 0.5, which indicates desorption of monomeric radicals from polymer particles. The exit (desorption) rate constants k(des)' (cm(2) s(-1)) and k(des) (s(-1)) were evaluated as a function of SDS concentration (or the particle size) according to the Ugelstad/O'Toole (I), Nomura (II) and Gilbert (III) models. The value of k(des) (s(-1)) decreases with increasing particle size (or SDS concentration) for all three (I, II and III) models. A complex trend appears for k(des) (cm(2) s(-1)): the Ugelstad/O'Toole model estimates a decrease, the Nomura model finds no variation and the Gilbert model estimates even a slight increase in k(des)'. with increasing SDS concentration. (c) 2006 Society of Chemical Industry