| 摘要 |
The invention provides a process for the preparation of polymer particles having a mode particle size of at least 50 mum which process comprises (a) obtaining a first particulate polymer seed material having a mode particle diameter of no more than 50 mum; (b) using said first seed material, performing a suspension polymerization involving the steps: (i) forming an aqueous dispersion comprising a polymer seed material, an organic compound (e.g. a polymerization initiator) which has a molecular weight of less than 5000 Daltons and a water solubility of less than 10-2 g/L at 25° C., a stabilizer and optionally an organic solvent (e.g. acetone or a portion of the monomer mentioned below); (ii) allowing said organic compound to diffuse into the seed material to produce an activated seed material; and (iii) contacting said activated seed material with a monomer (e.g. styrene) and with a polymerization initiator and effecting suspension polymerization thereof and (c) optionally impregnating and/or heat treating and/or surface modifying the particulate product of step (b). |
