COMPARISON OF PREPARATION, CHARACTERIZATIONS OF CARBAMOYLETHYL HEMICELLULOSES IN DIFFERENT MEDIA
Chemical modification is the most important mean to design novel biopolymer and biomaterials from the abundant and biocompatible hemicelluloses. In this paper, the objective of this study was to compare the characterization of carbamoylethyl hemicelluloses prepared in different solvents. The comparative methods to synthesize carbamoylethyl hemicelluloses were developed by the etherification of hemicelluloses with acrylamide in aqueous alkaline solution, ethanol, isopropanol, butanol, ethanol/acetone, and N, N-dimethylformamide systems under NaOH as catalyst. It was found that carbamoylethyl hemicelluloses with a relatively higher degree of substituent (DS) could be obtained in butanol medium. The physico-chemical properties of the carbamoylethyl hemicelluloses such as chemical structure and thermal stability were investigated by using GPC and 13C NMR spectroscopy as well as TG/DTA. The results showed that carbamoylethyl groups actually were grafted onto the main chain of hemicelluloses. Moreover, it was also found that the saponification of carbamoylethyl groups to carboxyl groups occurred in alkaline medium. By GPC analysis, it was found that the molecular weights (Mw) of modified hemicelluloses were lower than that of unmodified hemicelluloses, which could be implied that a degradation of the polymers occurred during the etherification. The behavior of carbamoylethyl hemicelluloses was monitored by means of TG/DTA. It was found that thermal stability of hemicelluloses after chemical modification decreased.
carbamoylethyl hemicelluloses preparation different solvents characterization
Jun L. Ren Xin W. Peng Feng Peng Run C. Sun
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou Institute of Biomass Chemistry and Technology, Beijing Forestry University, Beijing 100083, China State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou
国际会议
16th International Symposium on Wood,Fiber and Pulping Chemistry(第十六届木材、纤维及制浆化学国际会议)
天津
英文
397-401
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）