THE MANUFACTURE OF CROSSLINKED COPOLYMER BEADS, THE COPOLYMER BEADS THEMSELVES AND THEIR USE AS ADSORBENTS OR, ON INCORPORATION OR ADDITION OF FUNCTIONAL GROUPS, AS ION EXCHANGE RESINS

摘要

Polymer beads are produced by forming an agitated suspension of lightly crosslinked seed particles, at least substantially free of protective colloid, swelling these by addition of monomer under polymerization conditions while balancing suspension conditions, feed rate, agitation and polymerization rate to avoid, discourage or minimise particle agglomeration, continuing polymerisation after monomer feed is completed and separating the resulting beads. The monomers in the seed particles and monomer feed comprise styrenic and/or aliphatic ethylenically unsaturated units and a suitable light degree of crosslinking of the seed particles is 0.1 to 5%. The beads when macroreticular are useful as adsorbents and when containing ion exchange functional groups, are useful, whether gel or macroreticular, as ion exchange resins. Preferred beads exhibit multi-stage swelling in a swelling solvent and have a birefringence pattern under polarised light characteristic of high bead stress.