On the determination of charge and nitrogen content in cellulose fibres modified to contain quaternary amine functionality.

Autor: Sjölund J; Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden; FibRe Center for Lignocellulose-based Thermoplastics, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. Electronic address: johsjol@kth.se., Westman G; Department of Chemistry and Chemical Engineering, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden; FibRe Center for Lignocellulose-based Thermoplastics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden. Electronic address: westman@chalmers.se., Wågberg L; Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden; FibRe Center for Lignocellulose-based Thermoplastics, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. Electronic address: wagberg@kth.se., Larsson PA; Department of Fiber and Polymer Technology, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden; FibRe Center for Lignocellulose-based Thermoplastics, KTH Royal Institute of Technology, SE-100 44 Stockholm, Sweden. Electronic address: perl5@kth.se.
Jazyk: angličtina
Zdroj: Carbohydrate polymers [Carbohydr Polym] 2025 Jan 01; Vol. 347, pp. 122734. Date of Electronic Publication: 2024 Sep 10.
DOI: 10.1016/j.carbpol.2024.122734
Abstrakt: Research interest in quaternization of cellulose fibres has increased considerably over the past decades. However, there is little or no consensus regarding how to characterize the material in terms of degree of substitution (DS), and the literature suggests a range of different methods focusing on charge determination as well as nitrogen content quantification. This work aims to fill the knowledge gap regarding how the different methods perform in relation to each other, and for what cellulosic systems each method has advantages, disadvantages and even potential pitfalls. FT-IR and NMR measurements are used to establish successful modification and determine the relative number of substituent groups. Another six methods are compared for the determination of the DS of cellulosic fibres and nanofibrils. The methods include Kjeldahl measurements, nitrogen determination by chemiluminescence, determination of molecular nitrogen by the Dumas method, colloidal titration, conductometric titration and polyelectrolyte adsorption. It can be concluded that most techniques investigated are reliable within certain ranges of DS and/or when using appropriate post-treatment of the quaternized material and suitable sample preparation techniques. The results from the present work hence provide recommendations to make an educated choice of method, and experimental protocol, based on the technique at hand.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2024 The Authors. Published by Elsevier Ltd.. All rights reserved.)
Databáze: MEDLINE
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