Suspension thiol-ene photopolymerization: Effect of stabilizing agents on particle size and stability

The impact of several surfactant species employed in the suspension photopolymerization of water-borne thiol-ene polymer microspheres is reported. The focus of analysis was on how different surfactant species and the surfactant concentrations affected particle size and particle size distributions. Surfactants used included sodium dodecyl sulfate (SDS), sodium dodecylbenzene sulfonate (SDBS), dodecyltrimethylammonium bromide (DTAB), tetradecyltrimethylammonium bromide (TTAB), and hexadecyltrimethylammonium bromide (HTAB), Tween 20, Tween 40, Tween 60, Tween 80, Lutensol XL 70, Lutensol XP 70, Pluronic PE 6400, and Pluronic F108 Pastille. Using stabilizing agents or surfactants is necessary to prevent extensive aggregation and agglomeration of crosslinked thiol-ene polymer. All surfactants used in this study for particle stabilization and development produced spherical thiol-ene polymer particles. The chemical structure and concentration of the surfactants influenced the final particle size and size distribution of particles obtained. In general, it was found that smaller particles are obtained with higher concentrations of stabilizing agent, especially for ionic surfactants.