Abstract

This study has investigated the dissolution of cotton fibres in the ionic liquid 1-ethyl-3-methylimidazolium acetate ([C2mim][OAc]) for three fibre arrangements. Dissolution was carried out with excess [C2mim][OAc] at various temperatures and times followed by coagulation with water. Optical microscopy (OM) of the resulting processed and dried cotton fibres indicated that this procedure produced a coagulated fraction surrounding the original fibres. X-ray diffraction (XRD) showed that the crystal structure of this coagulated fraction was predominantly cellulose II, as opposed to the original fibres—mostly cellulose I. The OM and XRD results showed that growth of the coagulated fraction obeyed time–temperature superposition (TTS) and displayed an Arrhenius behaviour allowing a dissolution activation energy to be determined. Although the growth of the coagulated fraction with time were different for these distinct three arrangements, all could be individually shifted to form master curves using TTS, leading to very similar activation energies, 96 ± 3 kJ/mol (23 ± 1 kcal/mol).

Graphic abstract

中文翻译：

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用时间-温度叠加研究三种不同纤维排列对乙酸1-乙基-3-甲基咪唑鎓盐溶解棉的影响

摘要

这项研究已经研究了棉纤维在离子液体1-乙基-3-甲基咪唑鎓乙酸盐（[C2mim] [OAc]）中对于三种纤维排列的溶解情况。在不同的温度和时间下用过量的[C2mim] [OAc]进行溶解，然后用水凝结。所得的经加工和干燥的棉纤维的光学显微镜（OM）表明该程序产生了围绕原始纤维的凝结部分。X射线衍射（XRD）显示，该凝结部分的晶体结构主要是纤维素II，与原始纤维（主要是纤维素I）相反。OM和XRD结果表明，凝结部分的生长服从时间-温度叠加（ TTS）并显示Arrhenius行为，从而可以确定溶出活化能。

图形摘要