Influence of Swelling Media on the Crystallinity and Accessibility of Lyocell Fibers: An FTIR and ¹³C NMR Analysis

ABSTRACT

Cellulose swelling using different protic, aprotic and alkaline solvents, which are capable of penetrating crystalline parts of cellulose is one of the important methods to enhance the accessibility and, as a result, the reactivity of cellulose in modification reactions. Here we discuss changes in the structure of cellulose II in never-dried Lyocell fibers upon swelling with different solvents and aqueous solutions using FTIR as well as solid-state ¹³C NMR spectroscopies and DSC thermal analysis. Changes in the water retention behavior and accessibility of fibers were correlated with solvent-related changes in the fiber structure and were in accordance with the results obtained by FTIR and ¹³C NMR spectroscopies.

Graphical Abstract

摘要

利用不同的质子、非质子和碱性溶剂对纤维素进行溶胀，这些溶剂能够穿透纤维素的结晶部分，是提高纤维素的可接近性和改性反应活性的重要方法之一. 本文利用FTIR、固态13cnmr和DSC热分析等方法，讨论了未干燥的Lyocell纤维在不同溶剂和水溶液溶胀时纤维素II结构的变化. 纤维的保水性和可及性的变化与溶剂相关的纤维结构变化有关，并与FTIR和13cnmr光谱结果一致.

关键词:

• ¹³CCP/MAS-NMR
• 结晶度
• DSC
• FTIR
• 肿胀
• KEYWORDS
• ¹³c cp/mas-nmr
• crystallinity
• dsc
• ftir
• lyocell
• swelling

Acknowledgments

Hereby the authors express their gratitude to Professor Dr. Thomas Rosenau, Dr. Hubert Hettegger and Dr. Markus Bacher from the University of Natural Resources and Life Sciences, Vienna (BOKU), Austria, Department of Chemistry, Institute for Chemistry of Renewable Resources, for supporting F.F. in performing the experimental and analytical work within the framework of her Ph.D. thesis. Lenzing AG (Austria) is acknowledged for providing Lyocell fibers to F.F.

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