R. Sun, J. Tomkinson, Jianchao Liu
Oct 1, 1999
Citations
0
Influential Citations
16
Citations
Journal
Polymer Journal
Abstract
Oleoylated hemicelluloses with degrees of substitution between 0.24 and 1.67 were prepared by a rapid esterification of wheat straw hemicelluloses with oleoyl chloride using 4-dimethylaminopyridine as a catalyst and triethylamine as a neutralizer in homogeneous N,N-dimethylformamide and lithium chloride system. The effects of oleoyl chloride concentration, reaction duration, and triethylamine concentration have been studied. Under an optimum condition (sample 12, molar ratio 1 : 3), over 90% of the free hydroxyl groups in native hemicelluloses were oleoylated in 35 min at 75°C. The new materials were characterized by FT-IR. GPC, and thermal analysis. The molecular weight measurements (39700–110900) showed only a minimal degradation of hemicellulosic chains during the rapid reactions at 75°C for 15–40 min.