STUDIES ON APPLICATIONS OF NATURAL POLYPHENOL-PHENOL-FORMALDEHYDE COPOLYMER BASED CATION-EXCHANGE RESINS

Naturally occurring polyphenol(condensed tannin)-phenol-formaldehyde c opolymer matrix based cation exchange resins have been successfully us ed as a solid catalyst (in H+ ion form) in the inversion of sucrose an d hydrolysis of methyl acetate. Apart from the normal advantages of th e solid catalysts over the acid catalysts in the solution phase, the v alues of the activation energy, entropy, and enthalpy of activation of the reactions involved reveal that the resins prepared acted as a cat alyst with characteristics comparable to those of the commercially ava ilable resins based on a styrene-DVB matrix. The resins have also been successfully used for softening of hard water and enrichment of metal ion concentration from very dilute solutions. (C) 1995 John Wiley and Sons, Inc.