Martin-Bertelsen Birte, Andersson Erika, Köhnke Tobias, Hedlund Artur, Stigsson Lars, Olsson Ulf
Division of Physical Chemistry, Lund University, 221 00 Lund, Sweden.
Division Materials and Production, RISE Research Institutes of Sweden, 431 53 Mölndal, Sweden.
Polymers (Basel). 2020 Feb 5;12(2):342. doi: 10.3390/polym12020342.
Cotton production is reaching a global limit, leading to a growing demand for bio-based textile fibers produced by other means. Textile fibers based on regenerated cellulose from wood holds great potential, but in order to produce fibers, the components need to be dissolved in suitable solvents. Furthermore, the dissolution process of cellulose is not yet fully understood. In this study, we investigated the dissolution state of microcrystalline cellulose in aqueous NaOH by using primarily scattering methods. Contrary to previous findings, this study indicated that cellulose concentrations of up to 2 wt % are completely molecularly dissolved in 8 wt % NaOH. Scattering data furthermore revealed the presence of semi-flexible cylinders with stiff segments. In order to improve the dissolution capability of NaOH, the effects of different additives have been of interest. In this study, scattering data indicated that the addition of ZnO decreased the formation of aggregates, while the addition of PEG did not improve the dissolution properties significantly, although preliminary NMR data did suggest a weak attraction between PEG and cellulose. Overall, this study sheds further light on the dissolution of cellulose in NaOH and highlights the use of scattering methods to assess solvent quality.
棉花产量正接近全球极限，这导致对通过其他方式生产的生物基纺织纤维的需求不断增长。基于木材再生纤维素的纺织纤维具有巨大潜力，但为了生产纤维，其成分需要溶解在合适的溶剂中。此外，纤维素的溶解过程尚未完全明晰。在本研究中，我们主要通过散射方法研究了微晶纤维素在氢氧化钠水溶液中的溶解状态。与之前的研究结果相反，本研究表明，在8 wt%的氢氧化钠中，浓度高达2 wt%的纤维素完全以分子形式溶解。散射数据还揭示了存在带有刚性链段的半柔性圆柱体。为了提高氢氧化钠的溶解能力，不同添加剂的效果备受关注。在本研究中，散射数据表明，添加氧化锌减少了聚集体的形成，而添加聚乙二醇并没有显著改善溶解性能，尽管初步的核磁共振数据确实表明聚乙二醇与纤维素之间存在微弱的吸引力。总体而言，本研究进一步阐明了纤维素在氢氧化钠中的溶解情况，并突出了使用散射方法来评估溶剂质量。
