Particle size distributions of P(VAc-co-MMA) beads produced through nonconventional suspension copolymerizations

Polymer beads have been used in vascular embolization procedures over the past few years. However, the main challenge during the polymer production stage is the manufacture of embolic agents with suitable particle diameters and narrow particle size distributions, in order to avoid the production of off-spec material and make the desired application safer. For this reason, the present work investigates the effects of different operation strategies on the particle size distributions of poly(vinyl acetate-co-methyl methacrylate) (P(VAc-co-MMA)) particles produced through nonconventional suspension copolymerizations. The analyzed strategies included: semi-suspension copolymerizations; semi-batch operations; addition of polymer to the initial dispersion; and addition of inhibitors to aqueous phase and their combinations, in accordance with a statistical experimental design. It is shown that it is possible to obtain particles with suitable average diameters and narrower particle size distributions through hybrid nonconventional operations of suspension copolymerizations that combine different aspects of the more traditional operation techniques. [Display omitted] •Hybrid operations of suspension copolymerizations allows the control of PSD.•All nonconventional operation strategies affect molecular weight distributions.•The use of inhibitor allowed the production of particles with suitable properties.•The combination of inhibitor and organic load provided the optimal process condition.