State Key Laboratory of Pulp and Paper Engineering, South China University of Technology, Guangzhou, China.
Carbohydr Res. 2008 Nov 24;343(17):2956-62. doi: 10.1016/j.carres.2008.08.023. Epub 2008 Aug 30.
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.
在温和条件下，通过在均相介质（N，N-二甲基甲酰胺-氯化锂）中用 4-二甲氨基吡啶作为催化剂使天然小麦秸秆半纤维素聚合物与月桂酰氯反应，合成了取代度为 0.46 至 1.54 的基于半纤维素的疏水生物材料。还研究了其他催化剂，如 N-溴代丁二酰亚胺、N-甲基吡咯烷、N-甲基吡咯烷酮和吡啶。在最佳反应条件下（每羟基 2 当量的月桂酰氯和三乙胺，5% 4-二甲氨基吡啶，40°C，35 分钟），获得了高取代度 1.54。通过傅里叶变换红外光谱和（13）C NMR 光谱以及热分析对生物材料进行了表征。结果表明，月桂酰化主要发生在半纤维素的β-D-Xylp 单元的 C-3 羟基上，酯化使疏水聚合物的热稳定性增加。
