Kinetics of styrene minisuspension polymerization using a mixture PVA-SDS as stabilizer

The kinetics of minisuspension polymerization of styrene at 70 °C using 2-2′-azobisisobutyronitrile (AIBN) as initiator, polyvinyl alcohol (PVA) and mixture PVA-sodium dodecyl sulfate (SDS) as stabilizers, were studied. The monomer was pre-dispersed by using a high-speed homogenizer apparatus that allowed use mild agitation conditions during the polymerization. It was observed that addition of SDS to a polymerization initially stabilized with PVA highly enhances the colloidal stability of the system. Interfacial tension, viscosity and stability ratio measurements suggest that the PVA and SDS molecules form associations that lead to an electroesteric stabilization mechanism.