Citric acid used as a crosslinking agent for the grafting of chitosan onto woolen fabric

Abstract

Modification of woolen fabrics was done by the grafting of low-molecular-weight deacetylated chitosan in the presence of citric acid as a crosslinking agent with the pad-dry cure method at different conditions (times and temperatures). The add-on of chitosan and the optimum conditions were determined. The improved properties of modified wool by chitosan were evaluated with the urea bisulfite solubility test, crease recovery angle, yellowness index, and scanning electron microscopy. The dyeing properties of modified wool fabrics were studied with acid and reactive dyes. The biocidal activities of the modified and unmodified wool samples were evaluated and compared against some species of microorganisms, including Escherichia coli (Gram negative), Staphylococcus aureus (Gram positive), Candida albicans, and Aspergillus flavus.

Viscoelastic Properties of Crosslinked Chitosan Films

“…Genipin, an extract from gardenia and jagua fruit, is another option [22,23], and although reported to have herbal benefits and is used for drug delivery [22], it has not yet been approved by the USA Food and Drug Administration. Citric acid is non-toxic and has been used as a crosslinker for chitosan and other polysaccharides for edible films [8,[24][25][26], textiles [27,28], and hydrogels for drug delivery [29][30][31]. The reactions between chitosan and citric acid take place in the films at temperatures between 110 to 190 • C [8,32], ranging from a few minutes to several hours [8,32,33], with citric acid concentrations of 5 to 30% (of dry polymer weight) [34], and either with [8,35] or without [26,29,32] a catalyst.…”

Deriving Structure‐Performance Relations of Chemically Modified Chitosan Binders for Sustainable High‐Voltage LiNi0.5Mn1.5O4 Cathodes

“…Thus, it does not qualify as a crosslinker of environmentally benign binders for sustainable lithium‐ion battery production . Therefore, other molecules, such as polyacrylic acid (PAA) and citric acid (CA), known from different branches of metal recovery and wood industry, have recently been adapted for silicon/graphite composite electrodes for lithium‐ion batteries. These have led to an improved chitosan‐based binder after carefully adjusting the ratios of PAA, chitosan, CA, and the acetic acid necessary for dissolving chitosan in water .…”

“…These have led to an improved chitosan‐based binder after carefully adjusting the ratios of PAA, chitosan, CA, and the acetic acid necessary for dissolving chitosan in water . Although the resulting electrodes displayed higher first cycle coulombic efficiency and better cycling stability over 50 cycles, ascribed to the higher tensile strength introduced by the citric acid crosslinking, the authors mentioned that it would not be possible to remove the acetic acid contamination from the electrode slurry . This certainly has an impact on the final electrode's mechanical and electrochemical properties since the acetic acid possibly binds to the deacetylated glucosamine units of chitosan, but is too short for bridging the chitosan chains.…”

Preparation and controllable release of chitosan/vanillin microcapsules and their application to cotton fabric

“…Physical cross‐linkers demonstrated poor mechanical strength and the resulted microspheres have exhibited inferior release properties due to their weak electrostatic interactions . Recently, the use of citric acid, as a safe cross‐linking agent for the grafting of chitosan onto woollen fabric, was tried …”