Willow Lignin Recovered from Hot‐Water Extraction for the Production of Hydrogels and Thermoplastic Blends

Abstract

A blend of commercial willow cultivars (Salix spp.) was subjected to hydrothermal pretreatment: hot‐water extraction in a pilot plant 65‐ft3 digester. Lignin recovered from the autohydrolyzate (willow lignin, WL) was used to produce hydrogels and thermoplastic blends. Lignin‐kaolin‐acrylamide (WL 10.7 % w/w) and lignin‐poly(ethylene)glycol diglycidyl ether (WL 66.7 % w/w) hydrogels exhibited favorable adsorption and absorption properties, respectively. Dye adsorption kinetics, swelling capacities, fragrance emanation, and compression moduli were measured for the hydrogels, along with SEM characterization. Additionally, WL was esterified by acetylation (C2, WAc) and acylation with lauroyl chloride (C12, WFAE and WFAEH). The crude and esterified lignin samples were blended (1–12 % w/w) with polylactic acid (PLA) via lab‐scale melt extrusion to produce thermoplastic blends. The physicochemical properties of the blends were evaluated. They exhibited an increase in degradation temperature and UV absorbance with potential to hinder photodegradation of PLA and may be leveraged in packaging applications.

Effects of alkali treatment on properties of willow bark fiber as potential fillers for polymer composites

“…The absorption band at 3418 cm −1 for the hydrogen bonded O-H group, due to the cellulose structure, 21 became broader in the spectra of WP. The peak at 1740 cm −1 represented the ester linkage of -COOH groups of ferulic and p-coumaric acids of lignin or hemicellulose, 23 which disappeared after degumming. Meanwhile, the peaks at 1063 and 1247 cm −1 , were attributed to the C–O stretching vibrations in phenols, alcohols, ethers, or esters of lignin, 19 which became much shallower in spectra of WP than in that of WB.…”

Recommendations for replacing PET on packaging, fiber, and film materials with biobased counterparts

“…243 Other approaches instead developed PLA/lignin mixtures. [244][245][246][247][248] Despite the interesting results achieved, the recycling of mixtures is always a practical challenge.…”

Lignin-Based Hydrogels for the Delivery of Bioactive Chaga Mushroom Extract

“…This biorefinery lignin is isolated from biomass using relatively mild autohydrolytic conditions and expected to contain a relatively preserved native lignin structure and properties, in contrast to kraft lignin, the dominant industrial lignin today, which is considerably modified during harsh kraft pulping conditions [ 19 ]. However, biorefinery lignin is lower in purity compared to kraft lignin, which has a relatively higher lignin content [ 20 ]. The synthesis of lignin-based HGs is a relatively new research area, with the oldest reports being made only in the last few decades [ 21 ].…”