KINETIC STUDY OF RAPID STEP CMC ENZYMATIC HYDROLYSIS

摘要

A kinetic study of enzymatic hydrolysis in the first rapid step is performed for carboxymethylcelluloses (CMC) with different structural characteristics,obtained in media consisting of organic solvents or mixtures of organic solvents of various compositions.The enzymatic activities were determined by a viscosimetric method,being correlated with the total degree of substitution (DS) and distribution of carboxymethyl groups on the secondary carbon atoms (DS_(2+3)),as well as with the method used for derivatives' synthesis.It is observed that CMC biodegradability in the rapid step is higher for polymers synthesized in media consisting of pure solvents,or in acetone-containing systems.Also,substrates having lower DS_(2+3) values are more susceptible to enzymatic attack.Statistic analysis of the experimental data showed that it is in this period of degradation that bonds adjacent to substituted anhydroglucose units can be also hydrolyzed by the enzymes.