title: Rapid esterification of wheat straw hemicelluloses induced by microwave irradiation.
abstract: Esterification of wheat straw hemicelluloses with acetyl chloride, propionyl chloride, n-octanoyl chloride, lauroyl chloride, palmitoyl chloride, stearoyl chloride, and oleoyl chloride, respectively, using N-bromosuccinimide (NBS) as a catalyst was achieved in DMF/LICl medium by microwave irradiation. The effects of various acyl chlorides and the molar ratios of xylose units in hemicelluloses/acyl chloride on the degree of substitution (DS) were investigated and DS reached up to 1.34 by a few minutes. (13)C NMR studies showed that the esterification occurred preferentially at the C-3 and C-2 positions. On the other hand, microwave irradiation brought a partial degradation of the polymer, and therefore resulted in a slight decrease in thermal stability of the hemicellulosic derivatives in comparison with conventional heating technique.
authors.affiliation: College of Material Science and Technology, Beijing Forestry University, Beijing, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Xu
authors.affiliation: College of Material Science and Technology, Beijing Forestry University, Beijing, China.
authors.forename: Jian-Xing
authors.initials: JX
authors.lastname: Jiang
authors.affiliation: College of Material Science and Technology, Beijing Forestry University, Beijing, China; State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China. Electronic address: bcs00a@bangor.ac.uk.
authors.forename: Run-Cang
authors.initials: RC
authors.lastname: Sun
authors.affiliation: College of Forestry, The North-Western University of Agricultural and Forestry Sciences and Technology, Yangling, China.
authors.forename: Dai
authors.initials: D
authors.lastname: She
authors.affiliation: College of Forestry, The North-Western University of Agricultural and Forestry Sciences and Technology, Yangling, China.
authors.forename: Bai
authors.initials: B
authors.lastname: Peng
authors.affiliation: College of Forestry, The North-Western University of Agricultural and Forestry Sciences and Technology, Yangling, China.
authors.forename: Jin-Xia
authors.initials: JX
authors.lastname: Sun
authors.affiliation: Birmingham Carbohydrate and Protein Technology Group, School of Chemistry, University of Birmingham, Birmingham B15 2TT, UK.
authors.forename: John F
authors.initials: JF
authors.lastname: Kennedy
keywords: (13)C NMR; Esterification; Hemicelluloses; Microwave; Thermal stability