Isolation and characterisation of cellulose obtained by a two-stage treatment with organosolv and cyanamide activated hydrogen peroxide from wheat straw
Isolation and characterisation of cellulose obtained by a two-stage treatment with organosolv and cyanamide activated hydrogen peroxide from wheat straw
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DOI：
10.1016/j.carbpol.2003.10.004
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发表时间：
2004-03
影响因子：
11.2
通讯作者：
X. Sun;R. Sun;P. Fowler;M. Baird
中科院分区：
文献类型：
--
作者：
X. Sun;R. Sun;P. Fowler;M. Baird
采用酸性有机溶剂处理和氨腈活化过氧化氢漂白的方法，对七种麦草纤维素进行了分离。研究了乙酸和甲酸浓度对纤维素得率、木质素和非纤维素多糖降解的影响。有机酸对木质素和半纤维素的降解效果优于醇类。甲酸/乙酸/水（30/60/10，v/v/v）体系被发现是最有效的脱木质素和从稻草中除去非纤维素多糖，并且对纤维素性质如其特性粘度没有任何不良影响。在这种情况下，使用0.1%HCl作为催化剂在85 °C下处理4小时，去除了94.1%的原始木质素和76.5%的原始半纤维素。氰胺活化过氧化氢漂白降解了大量的残留半纤维素和木质素，产生了具有相对较高纯度的纤维素样品。在最佳条件下，获得了相对不含木质素（0.7%）、特性粘度为393 ml g-1和有利摩尔质量（213，940 g mol-1）的纤维素。未漂白和漂白的纤维素制剂进一步通过FT-IR和CP/MAS 13 C NMR光谱和热稳定性表征。
Seven wheat straw cellulose preparations were isolated by a two-stage acidic organosolv treatment followed by cyanamide activated hydrogen peroxide bleaching. The effects of concentration of acetic and formic acids on the yield of cellulose and degradation of lignin and non-cellulose polysaccharides were investigated. Organic acids were more effective than alcohols on the degradation of lignin and hemicelluloses. Formic acid/acetic acid/water (30/60/10, v/v/v) system was found to be the most effective in delignification and removal of non-cellulose polysaccharides from the straw and did not have any undesirable effects on cellulose properties such as its intrinsic viscosity. In this case, the treatment removed 94.1% of the original lignin and 76.5% of the original hemicelluloses using 0.1% HCl as a catalyst at 85 °C for 4 h. Cyanamide activated hydrogen peroxide bleaching degraded substantial amounts of residual hemicelluloses and lignin, produced the cellulose samples having a relatively high purity. Under a best condition, a cellulose relatively free of lignin (0.7%) and with intrinsic viscosity of 393 ml g−1and favourable molar mass (213,940 g mol−1) was obtained. Both unbleached and bleached cellulose preparations were further characterised by FT-IR and CP/MAS13C NMR spectroscopy, and thermal stability.