Synthesis and Characterization of Hydrophobically Modified Xylans

Abstract

Xylan is a major type of hemicellulose that has attracted a lot of research and development activities. It is often derivatized in order to improve its properties. In the literature, hydrophobic modification of polymers is often used to produce surfactant-like materials and associative thickeners. In this work, we have derivatized xylan with alkyl ketene dimer (AKD) and two types of alkenyl succinic anhydrides (ASAs). The xylan-AKD derivatives have been made at 90 °C, using dimethyl sulfoxide as solvent and 4-dimethylaminopyridine as promoter. Samples with degrees of substitution (DS) up to 0.006 have been produced. The xylan-ASA derivatives have been synthesized at 120 °C in dimethyl sulfoxide with DS up to 0.105–0.135. The structures of these products have been confirmed with NMR and FT-IR. These xylan derivatives increase the structural diversity of xylan and provide additional options for people seeking to use hydrophobically modified polysaccharides in their applications.

Production and Anti-Inflammatory Performance of PVA Hydrogels Loaded with Curcumin Encapsulated in Octenyl Succinic Anhydride Modified Schizophyllan as Wound Dressings

“…It was observed that the grafting of the octenyl succinate chains onto the SPG may have caused the lower degradation temperatures, which is illustrated by the fact that the introduction of the OS group negatively affected the thermal stability of SPG. The decrease in the thermal stability was caused by the weakened hydrogen bonds between the hydrophobic alkenyl group and SPG, resulting in a lower required energy input for bond breakage, which is similar to Cheng’s report [ 40 ]. The decrease in the thermal stability was caused by the weakened hydrogen bonds between the hydrophobic alkenyl group and SPG, resulting in a lower required energy input for bond breakage [ 41 ].…”

Side chains affect the melt processing and stretchability of arabinoxylan biomass-based thermoplastic films

“…An alkylketene dimer and an alkenyl succinic anhydride were used to hydrophobize xylan in a recent study, but thermoplasticity was not achieved (Cheng et al, 2021). Previous studies have demonstrated that ring opening polymerization of ε-caprolactone on hemicellulose can make it melt processable (Farhat et al, 2018;Svärd et al, 2018) We previously demonstrated that AX with a high araf/xylp (0.8 and 1.1) after one-step and two-step functionalization with BuGE can potentially be processed using the polymer processing technique (Börjesson et al, 2019a(Börjesson et al, , 2019bDeralia et al, 2021aDeralia et al, , 2021b.…”

Improving Barrier Properties of Xylan-Coated Food Packaging Papers with Alkyl Ketene Dimer

“…However, free hydroxyl groups are available for chemical functionalization of xylan (i.e., esterification, etherification, crosslinking, etc.) with hydrophobic functional groups, especially when it is used for packaging and coating applications [18].…”

“…The chemical reaction of AKD with xylan hemicelluloses occurs at free hydroxyl groups from 2 and/or 3 positions of xylan monomer unit. As result, the hydrophobic moieties of β-ketoester and fatty acid chains are introduced, and the amphiphilicity as well as the surface activity of hemicellulose are enhanced (Figure 1) [18,45]. in the field of new types of hydrophobic xylans.…”

“…The chemical reaction of AKD with xylan hemicelluloses occurs at free hydroxyl groups from 2 and/or 3 positions of xylan monomer unit. As result, the hydrophobic moieties of β-ketoester and fatty acid chains are introduced, and the amphiphilicity as well as the surface activity of hemicellulose are enhanced (Figure 1) [18,45]. Even if it is known that in the papermaking process the AKD size has efficiency at high temperatures, it has been proved that AKD is relatively unreactive towards both water and hydroxyl-containing compounds, including cellulosic fibres, starch products, or other polysaccharides [46].…”