THERMAL SENSITIVE HYDROGELS PREPARED FROM HEMICELLULOSES ULTRASONICALLY EXTRACTED FROM CORNCOB
The water-insoluble (hemicellulose A) and watersoluble (hemicellulose B) hemicelluloses were isolated from corncobs by a two-step ultrasoundassisted alkali extraction process. In step 1, the corncob meshes were treated by ultrasound under different alkali concentration conditions for 10 min and the residues in the first process were extracted by diluted alkali solution at ambient temperature for 3 hours in step 2. The yield, monosaccharide composition and molecular weight of both the hemicelluloses obtained from the two steps and those extracted by conventional method were characterized by the gravity method, IC and GPC, respectively. The results showed that the yields of hemicelluloses obtained by ultrasound-assisted extraction were slightly higher than that obtained from the conventional extraction. Moreover, most of the former ones had a higher content of arabinose than the later ones, especially for the hemicellulose B, which could be deduced that the hemicelluloses from ultrasoundassisted extraction contained highly branched structure and thus these fractions showed better solubility. The thermal sensitive hydrogels were prepared by the hemicellulose B, including those obtained from ultrasound-assisted extraction with 2％ and 5％ KOH solution as well as those from the conventional extraction method via esterification reaction with maleic anhydride (MA) and crosslinkage under irradiation of UV light with the presence of Nisopropylacrylamide (NIPAAm) in DMF. The lower critical solution temperature (LCST) and thermal responsive property of the gels were investigated by DSC and probing the swelling/de-swelling behaviors of them under different temperatures as well.
hemicellulose extraction ultrasound hydrogel
Ju Fang Xuesong Zhou Cuicui Xue
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, 510640, China
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
402-407
2011-06-08（万方平台首次上网日期，不代表论文的发表时间）