Faculty of Chemistry and Pharmacy, University of Innsbruck , 6020 Innsbruck, Austria.
Biomacromolecules. 2013 Jun 10;14(6):1741-50. doi: 10.1021/bm400106h. Epub 2013 May 7.
Pulp of high cellulose content, also known as dissolving pulp, is needed for many purposes, including the production of cellulosic fibers and films. Paper-grade pulp, which is rich in hemicellulose, could be a cheap source but must be refined. Hitherto, hemicellulose extraction procedures suffered from a loss of cellulose and the non-recoverability of unaltered hemicelluloses. Herein, an environmentally benign fractionation concept is presented, using mixtures of a cosolvent (water, ethanol, or acetone) and the cellulose dissolving ionic liquid 1-ethyl-3-methylimidazolium acetate (EMIM OAc). This cosolvent addition was monitored using Kamlet-Taft parameters, and appropriate stirring conditions (3 h at 60 °C) were maintained. This allowed the fractionation of a paper-grade kraft pulp into a separated cellulose and a regenerated hemicellulose fraction. Both of these exhibited high levels of purity, without any yield losses or depolymerization. Thus, this process represents an ecologically and economically efficient alternative in producing dissolving pulp of highest purity.
高纤维素含量的纸浆，也称为溶解浆，用于多种用途，包括纤维素纤维和薄膜的生产。富含半纤维素的纸浆级纸浆可以作为廉价的来源，但必须进行精制。迄今为止，半纤维素的提取过程存在纤维素损失和未改变的半纤维素不可回收的问题。在此，提出了一种使用共溶剂（水、乙醇或丙酮）和纤维素溶解离子液体 1-乙基-3-甲基咪唑醋酸盐（EMIM OAc）的混合物的环境友好的分级概念。通过 Kamlet-Taft 参数监测共溶剂的添加，并保持适当的搅拌条件（60°C 下搅拌 3 小时）。这允许将纸浆级牛皮纸浆分级为分离的纤维素和再生的半纤维素级分。这两个级分都表现出高纯度，没有任何产率损失或解聚。因此，该工艺在生产最高纯度的溶解浆方面代表了一种生态和经济有效的替代方法。
