Rapid homogeneous lauroylation of wheat straw hemicelluloses under mild conditions.
Hemicellulose-based hydrophobic biomaterials with degrees of substitution ranging from 0.46 to 1.54 were synthesized under mild conditions in homogeneous media (N,N-dimethylformamide-lithium chloride) by reacting the native wheat straw hemicellulosic polymers with lauroyl chloride using 4-dimethylaminopyridine as a catalyst. Other catalysts such as N-bromosuccinimide, N-methyl pyrrolidine, N-methyl pyrrolidinone, and pyridine were also investigated. Under optimum reaction conditions (2 equiv of lauroyl chloride and triethylamine per hydroxyl group, 5% 4-dimethylaminopyridine, 40 degrees C, 35 min), a high DS value of 1.54 was obtained. The biomaterials were characterized by FT-IR spectroscopy and (13)C NMR spectroscopy as well as by thermal analysis. The results showed that the lauroylation occurred preferably at the C-3 hydroxyl group of beta-D-Xylp units in the hemicelluloses, and the thermal stability of the hydrophobic polymers increased by esterification.
Peng
Feng
F
State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China.
Ren
Jun-Li
JL
Peng
Bai
B
Xu
Feng
F
Sun
Run-Cang
RC
Sun
Jin-Xia
JX
D001089:Arabinose / Q000031:analogs & derivatives / Q000378:metabolism; D002247:Carbon Isotopes; D018556:Crops, Agricultural / Q000378:metabolism; D020723:Glucuronic Acid / Q000378:metabolism; D007700:Kinetics; D007850:Lauric Acids / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D009005:Monosaccharides / Q000032:analysis / Q000378:metabolism; D011134:Polysaccharides / Q000138:chemical synthesis / Q000737:chemistry / Q000378:metabolism*; D017550:Spectroscopy, Fourier Transform Infrared; D014908:Triticum / Q000378:metabolism*
D002247:Carbon Isotopes; D007850:Lauric Acids; D009005:Monosaccharides; D011134:Polysaccharides; C431714:arabinofuranose; C030358:lauric acid; C007916:hemicellulose; D020723:Glucuronic Acid; D001089:Arabinose