In this paper hemicellulose was separated by using 1-ethyl-3-methylimidazolium acetate (EmimAc, an ionic liquid) -water mixtures from a paper grade market bleached hardwood kraft pulp to produce dissolving pulp. Pure EmimAc dissolves pulp fibers completely in 30 min at ambient temperatures. By adding water (as an antisolvent to EmimAc system) the cellulose dissolution decreases and by optimizing the conditions, hemicellulose is largely removed while cellulose remains as the solid residue (dissolving pulp). At optimal conditions: molar ratio of water to EmimAc of 2, 60 °C, an alpha-cellulose content of 92.2%, with a high yield (78 wt%) was obtained. The viscosity of the solvent mixture decreases by increasing water to EmimAc molar ratio, which improves the mobility of ions, thus, facilitating their penetration into pores and lumens of the fibers during the dissolution process. Cellulose purity increases and purified cellulose yield decreases with the increases in temperature and water content (up to 2 wt%) in the mixture. This study implies that the optimal EmimAc/water mixture is an effective system to separate hemicellulose from hemicellulose/cellulose matrix.

在本文中，通过使用纸级市场漂白的硬木牛皮纸浆中的乙酸1-乙基-3-甲基咪唑鎓盐（离子液体）-水混合物分离半纤维素，以生产溶解纸浆。在环境温度下，纯EmimAc可在30分钟内完全溶解纸浆纤维。通过添加水（作为EmimAc系统的抗溶剂），纤维素溶解度降低，并且通过优化条件，半纤维素被大量去除，而纤维素则作为固体残留物（溶解浆）保留下来。在最佳条件下：水与EmimAc的摩尔比为2，60°C，α-纤维素含量为92.2％，具有高产率（78 wt％）。溶剂混合物的粘度通过增加水与EmimAc的摩尔比而降低，从而改善了离子的迁移率，因此，在溶解过程中促进它们渗透到纤维的孔和腔中。随着温度和混合物中水含量（最高2 wt％）的增加，纤维素的纯度增加，纯化的纤维素产量降低。这项研究表明，最佳的EmimAc /水混合物是将半纤维素与半纤维素/纤维素基质分离的有效系统。