PMMA encapsulation of alumina particles through aqueous suspension polymerisation processes

Two routes based on aqueous suspension polymerisation of methylmethacrylate (MMA) were investigated for the preparation of poly(methylmethacrylate) (P MMA) beads containing alumina particles. The compatibility of alumina surfa ce with MMA was achieved through the condensation of 3-(trimethoxysilyl)pro pylmethacrylate (gamma-MPS). The "dynamic" process consisted in the dispers ion of the modified alumina/MMA mixture as liquid droplets in an aqueous po lyvinylalcohol solution by vigorous stirring, which is maintained during po lymerisation. The "static" process utilised a water-agarose gel as a suspen ding phase. The present paper deals with the experimental parameters optimi sation, the hybrid alumina/PMMA beads characterisation and the discussion a bout advantages and drawbacks of both methods.