ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Preparation and SEM Characterization of Sterically Stabilized Polystyrene Particles

I. Capek, L. Chitu, S. Janíčková, I. Kostič, Š. Luby, E. Majková, and A. Šatka

Polymer Institute, Slovak Academy of Sciences, SK-842 36 Bratislava

E-mail: upolign@savba.sk

Received: 17 September 2003

Abstract: Batch emulsion polymerization of styrene was used to prepare the polystyrene particles. The emulsion polymerization was initiated either by the water-soluble initiator ammonium peroxodisulfate (APS) or the oil-soluble initiator 2,2
-azobisisobutyronitrile (AIBN). The nonionic emulsifier Tween 20 was used to stabilize the polymer particles. The polymerization rate vs. conversion dependence was characterized by three rate intervals. The APS-initiated polymerization was faster than the AIBN-initiated one. The polymer particles prepared by the APS-initiated emulsion polymerization were less monodisperse than those prepared by the AIBN-initiated polymerization. The (ordered monolayer) hexagonal arrangement of polymer particles prepared by the AIBN-initiated polymerization appears at the high emulsifier concentration or the large mass ratio emulsifier/monomer. The ordered SEM particle structures are initiated by the interpenetration of the thick interfacial layers of neighbouring polymer particles. The presence of charged groups in the emulsifier layer or the loosely organized emulsifier layer disfavours the ordered particle structures.

Full paper in Portable Document Format: 591a41.pdf

Chemical Papers 59 (1) 41–47 (2005)