Rapid esterification of wheat straw hemicelluloses induced by microwave irradiation

Feng Xu; Jian-Xing Jiang; Run-Cang Sun; Dai She; Bai Peng; Jin-Xia Sun; John F Kennedy

doi:10.1016/j.carbpol.2008.01.002

Rapid esterification of wheat straw hemicelluloses induced by microwave irradiation

Carbohydr Polym. 2008 Sep 5;73(4):612-20. doi: 10.1016/j.carbpol.2008.01.002. Epub 2008 Jan 11.

Authors

Feng Xu¹, Jian-Xing Jiang¹, Run-Cang Sun², Dai She³, Bai Peng³, Jin-Xia Sun³, John F Kennedy⁴

Affiliations

¹ College of Material Science and Technology, Beijing Forestry University, Beijing, China.
² 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.
³ College of Forestry, The North-Western University of Agricultural and Forestry Sciences and Technology, Yangling, China.
⁴ Birmingham Carbohydrate and Protein Technology Group, School of Chemistry, University of Birmingham, Birmingham B15 2TT, UK.

PMID: 26048228
DOI: 10.1016/j.carbpol.2008.01.002

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.

Keywords: (13)C NMR; Esterification; Hemicelluloses; Microwave; Thermal stability.