Tailoring of 4-vinylpyridine-based resins for hydrolytic degradation and solubilisation

Gel-type and macroporous 4-vinylpyridine-derived polymer resins have been p repared by suspension polymerisation employing ethylene glycol diacrylate, ethylene glycol dimethacrylate or divinylbenzene as the crosslinker. Each r esin has also been converted into its pyridinium ion form via methylation u sing methyl iodide, in effect producing the corresponding anion exchange re sins. The hydrolytic stability under both acidic and alkaline conditions of both the neutral and the cationic forms of all the resins has been assesse d. Crosslinks derived from the diacrylate monomer are the most hydrolytical ly labile whereas the dimethacrylate derived crosslinks cleave only under b asic conditions and when the resin is in its quaternised form. Remarkably a gel-type resin lightly crosslinked using divinylbenzene also degrades unde r similar conditions, and since the crosslink itself is likely to be stable it seems that mainchain scission is involved in this instance. (C) 1999 El sevier Science Ltd. All rights reserved.