New aspects in cationization of lignocellulose materials. III. Influence of delignification on reactivity and extractability of TMAHP–hemicelluloses

Abstract

SynopsisBeech sawdust samples with different lignin content were alkylated with 3chloro-2-hydroxypropyltrimethylammoniumchloride (CHMAC). The yields and the degree of substitution of trimethylammonium-2-hydroxypropyl (TMAHP) samples were similar. Differences were found in extractability of hemicelluloses from this materials both with water and dilute alkali. To obtain the maximum yield of TMAHP-hemicelluloses (ca. 90% of the amount originally present), it is sufficient to remove about 50% of lignin. The lignin component does not influence the reactivity of hemicelluloses. The isolated hemicelluloses differ only in the distribution of functional groups and extractability.

Quaternized agricultural by-products as anion exchange resins

“…Since lignin created a network across the cell wall surface, Antal et al (1984b) found the quaternization reaction with cellulose to be hindered. Moreover, Ebringerova et al (1986) also indicated that the delignification of lignocellulosic byproducts would increase reaction efficiency with CHMAC. These findings were corroborated by Orlando et al (2002b) who could not correlate anion exchange capacity with a-cellulose content in the quaternization of six agricultural by-products with epichlorohydrin and dimethylamine.…”

An anion exchange resin from soybean hulls

“…Since lignin created a network across the cell wall surface, the reaction between N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride and cellulose was hindered. Ebringerova et al 6 indicated that lignin also influences the distribution of functional groups after reaction with N-(3-chloro-2-hydroxypropyl) trimethylammonium chloride, but does not influence the reactivity of hemicellulose, unlike cellulose.…”

Cationic Xylan Derivatives with High Degree of Functionalization

“…[4] Regarding chemically modified products, the cationic 2-hydroxypropyltrimethylammonium (HPMA) xylan is well studied. [5][6][7] The synthesis was carried out in alkaline medium with 3-chloro-2-hydroxypropyltrimethylammonium chloride. Dependent on the molar ratio of xylan to reagent and of reagent to NaOH, derivatives with different degree of substitution (DS) up to 0.98 were obtained.…”