In situ polymerization of surface-active agents on latex particles

Reactive surfactants in heterophase polymerization

“…Similar results had been reported by Hatala [47] and Muroi [48]. Greene and Saunders [49] also studied the electrolyte stability of these two series of latexes finding that the stability of the latexes with non-polymerized NaAAS was lower than that of the latex with polymerized NaAAS.…”

Semi-continuous emulsion copolymerization of butyl methacrylate with polymerizable anionic surfactants

“…(4). As shown in Table 1, the surface composition of SABS-8 on these latex particles increased sharply from 22.6 to 69.3% as the SABS-8 content in the polymerization system was only increased from 0.6 to 1.5 wt% (samples [1][2][3]. This means that a slight increase in the feed composition of SABS-8 from 9.8, 15.4 to 21.4 wt% (based on BMA and SABS-8) led to a sharp increase of its surface coverage on the latex particles from 22.6, 50.5 to 69.3%, respectively.…”

“…This may be due to the better reactivity for SABS-n as compared to NaSS. The electron density of vinyl group -CHyCH 2 of NaSS may have been reduced by the strong electron-withdrawing group of sulfonate ion -SO 3 2 at the para-position of benzene ring. For each chain termination by transfer to monomer within a latex particle, a new growing free radical will thus be generated within that latex particle.…”

“…The increasing hydrophobic nature of these oligomeric radicals would favor their entries into BMA-swollen micelles for further copolymerization of BMA with SABS-n. In addition, it is also possible for oligomeric radicals to form stable new particles due to ionic stabilization (electrostatic repulsion) exerted by the sulfonate ions -SO 3 2 from the copolymerized SABS-n. After 30 min of prepolymerization, BMA monomer in the system was exhausted after the formation of primary polymer particles. This was the polymerization state where monomer-starved growing polymer particles prevailed.…”

“…As a result, desorption of surfactant from the polymer particles or migration in the polymer films is impeded. Such improvements of latex and/or polymer properties have been reported for mechanical stability [2], electrolyte stability of the latex [3], a decrease of surfactant migration [4] and control of surface charge density [5].…”