Treatment of a poly(allyl alcohol) with ethyl chloroformate in an anhydrous organic solvent mixture has produced an insoluble polymer containing a high proportion of carbonate functions. An appreciable number of these functions exist in cyclic form, possibly as eight-membered rings, which have proved to be susceptible to nucleophilic attack in aqueous media. By means of these groups, water-soluble enzymes have been bound under mild conditions to the polymer, acting as an insoluble support, to produce active solid-phase enzymes.