Based on the property that carboxymethylcellulose (CMC ) can be de-graded to anhydroglucose residues by cellulase, the rate constant (K) of enzymatic degra-dation of CMC synthesized in the benzene-ethanol medium has b...Based on the property that carboxymethylcellulose (CMC ) can be de-graded to anhydroglucose residues by cellulase, the rate constant (K) of enzymatic degra-dation of CMC synthesized in the benzene-ethanol medium has been determined. Further-morel experimental equation K = 2.71× 10^(-2)(DS)^(-1.2) reflecting the relationship betweenK and the degree of substitution (DS) is correlated and used to describe chemical mi-crostructure uniformity of the distribution of substituents along chains effectively. Chainstructure parameters of enzymatic degradation products of CMC-the number of chainbreaks and the percentage of glucose released have been also measured. Average length ofsubstituted and unsubstituted chain segments are calculated simultaneously. Through thestudy of static and dynamic procedures of enzymatic degradation, the method to charac-terize the distribution of substituents of CMC along the chain has been improved.展开更多
This study is focused on the viscosity behavior of the aqueous solution of the CMC prepared in a two phase medium C 6H 6 C 2H 5OH H 2O.The effects of properties such as the degree o...This study is focused on the viscosity behavior of the aqueous solution of the CMC prepared in a two phase medium C 6H 6 C 2H 5OH H 2O.The effects of properties such as the degree of substitution,molecular weight,distribution of substituent along the molecular chain or at positions C 2,C 3 and C 6 on viscosity are investigated respectively.The difference of the CMC synthesized in medium benzene ethanol and ethanol is studied.The addition of benzene is beneficial to improve the viscosity and stability of CMC solutions.The CMC with homogeneous distribution of substituent along the chain and the high substitution at position C 6 possess a good compatibility with organic acids and excellent resistance to alkali,salts and acid.展开更多
文摘Based on the property that carboxymethylcellulose (CMC ) can be de-graded to anhydroglucose residues by cellulase, the rate constant (K) of enzymatic degra-dation of CMC synthesized in the benzene-ethanol medium has been determined. Further-morel experimental equation K = 2.71× 10^(-2)(DS)^(-1.2) reflecting the relationship betweenK and the degree of substitution (DS) is correlated and used to describe chemical mi-crostructure uniformity of the distribution of substituents along chains effectively. Chainstructure parameters of enzymatic degradation products of CMC-the number of chainbreaks and the percentage of glucose released have been also measured. Average length ofsubstituted and unsubstituted chain segments are calculated simultaneously. Through thestudy of static and dynamic procedures of enzymatic degradation, the method to charac-terize the distribution of substituents of CMC along the chain has been improved.
文摘This study is focused on the viscosity behavior of the aqueous solution of the CMC prepared in a two phase medium C 6H 6 C 2H 5OH H 2O.The effects of properties such as the degree of substitution,molecular weight,distribution of substituent along the molecular chain or at positions C 2,C 3 and C 6 on viscosity are investigated respectively.The difference of the CMC synthesized in medium benzene ethanol and ethanol is studied.The addition of benzene is beneficial to improve the viscosity and stability of CMC solutions.The CMC with homogeneous distribution of substituent along the chain and the high substitution at position C 6 possess a good compatibility with organic acids and excellent resistance to alkali,salts and acid.
