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http://hdl.handle.net/10773/35936
Title: | Cationization of eucalyptus kraft lignoboost lignin: preparation, properties, and potential applications |
Author: | Pinto, Patrícia I.F. Magina, Sandra Budjav, Enkhjargal Pinto, Paula C.R. Liebner, Falk Evtuguin, Dmitry |
Issue Date: | 16-Mar-2022 |
Publisher: | American Chemical Society |
Abstract: | Current changes toward a more biobased economy have recently created tremendous renewed interest in using lignin as a valuable source for chemicals and materials. Here, we present a facile cationization approach aiming to impart kraft lignin water-solubility, with similar good features as lignosulfonates. Eucalyptus globulus kraft lignin obtained from a paper mill black liquor by applying the LignoBoost process was used as the substrate. Its reaction with 3-chloro-2-hydroxypropyl-trimethylammonium chloride (CHPTAC) in an aqueous alkaline medium was studied to assess the impact of different reaction conditions (temperature, time, educt concentration, molar CHPTAC-to-lignin ratio) on the degree of cationization. It has been shown that at pH 13, 10 wt % lignin content, 70 °C, and 3 h reaction time, a CHPTAC-to-lignin minimum molar ratio of 1.3 is required to obtain fully water-soluble products. Elemental analysis (4.2% N), size-exclusion chromatography (M w 2180 Da), and quantitative 13C NMR spectroscopy of the product obtained at this limit reactant concentration suggest introduction of 1.2 quaternary ammonium groups per C9 unit and substitution of 75% of the initially available phenolic OH groups. The possible contribution of benzylic hydroxyls to the introduction of quaternary ammonium moieties through a quinone methide mechanism has been proposed. Since both molecular characteristics and degree of substitution, and hence solubility or count of surface charge, of colloidal particles can be adjusted within a wide range, cationic kraft lignins are promising materials for a wide range of applications, as exemplarily demonstrated for flocculation of anionic dyes. |
Peer review: | yes |
URI: | http://hdl.handle.net/10773/35936 |
DOI: | 10.1021/acs.iecr.1c04899 |
ISSN: | 0888-5885 |
Appears in Collections: | CICECO - Artigos |
Files in This Item:
File | Description | Size | Format | |
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acs.iecr.1c04899.pdf | 2.47 MB | Adobe PDF | View/Open |
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