TYROSINASE REACTION CHITOSAN ADSORPTION - POTENTIAL FOR REMOVING POLYMERIZATION STORAGE INHIBITORS

Polymerization inhibitors are added to monomer solutions to prevent the inadvertent initiation of free radical polymerization during monomer storage and transportation. Residual levels of these inhibitors can be a source of irreproducibility in polymerization kinetics and can, therefore, disrupt efforts to control polymerization reactions for process optimization. We examined the feasibility of a non-capital-intensive separations approach for simply and efficiently removing the tert-butylcatechol storage inhibitor. The separations approach employs the enzyme tyrosinase to selectively oxidize the phenolic inhibitor, and the oxidation products are then strongly bound to a chitosan sorbent. For practicality we covalently immobilized the tyrosinase within chitosan gels to yield beads which served as both catalyst and sorbent for the phenolic inhibitor. These tyrosinase-containing chitosan gels were shown to be capable of removing low levels of tert-butylcatechol from both aqueous and organic phases and thus have the potential to be exploited for removing phenolic inhibitors in a range of polymerization operations. The use of tyrosinase-containing chitosan gels for waste minimization is discussed.