Structure and Properties of Oxidized Chitosan Grafted Cashmere Fiber by Amide Covalent Modification

Abstract

In this study, oxidized chitosan grafted cashmere fibers (OCGCFs) were obtained by crosslinking the oxidized chitosan onto cashmere fibers by amide covalent modification. A novel method was developed for the selective oxidation of the C6 primary hydroxyls into carboxyl groups for chitosan. The effect of oxidization reaction parameters of HNO3/H3PO4–NaNO2 mediated oxidation system on the oxidation degree, structure, and properties of chitosan were investigated. The chemical structure of the oxidized chitosan was characterized by solid-state cross-polarization magic angle spinning carbon-13 Nuclear Magnetic Resonance (CP/MAS 13C-NMR), Fourier transform infrared spectroscopy (FT-IR), and its morphology was investigated by scanning electron microscopy (SEM). Subsequently, the effect of the oxidized chitosan grafting on OCGCF was examined, and the physical properties, moisture regain, and antibacterial activity of OCGCFs were also evaluated. The results showed that oxidation of chitosan mostly occurred at the C6 primary hydroxyl groups. Moreover, an oxidized chitosan with 43.5–56.8% carboxyl content was realized by ranging the oxidation time from 30 to 180 min. The resulting OCGCF had a C–N amido bond, formed as a result of the reaction between the primary amines in the cashmere fibers and the carboxyl groups in the oxidized chitosan through the amide reaction. The OCGCF exhibited good moisture regain and remarkable bacteriostasis against both Staphylococcus aureus and Escherichia coli bacteria with its durability.

Anti-pilling and anti-static bifunctional finishing of cashmere knitted fabric based on combinatorial foaming microcoating of anionic hydrophilic polyurethane

“…According to the chemical structural (Scheme 1 and Scheme 2), TC polyurethane has superior moisture recovery performance 24 because it has a higher proportion of polyethylene glycol (PEG) chains in its molecular structure than BC polyurethane and shows better static resistance.…”

Hydrogels in Cutaneous Wound Healing: Insights into Characterization, Properties, Formulation and Therapeutic Potential

“…Moreover, it exhibits intrinsic antibacterial activity [ 9 , 11 , 16 , 46 , 52 , 53 , 137 ], which depends on its molecular weight, degree of deacetylation, concentration, and type of bacteria [ 184 ]. Several mechanisms have been proposed to elucidate this activity, with the most widely accepted one being that chitosan chains contain amino groups that can be protonated, giving them a positive charge.…”

“…Electrostatic interactions occur between the protonated amino groups (–NH 3 + ) of chitosan and the negative charges of the microbial cell membrane, leading to alteration of cell permeability, resulting in cell membrane lysis and, consequently, cell death [ 46 , 50 , 51 , 129 ]. Chitosan demonstrated a bacterial inhibition rate of 95.6% for Escherichia coli and 99.2% for Staphylococcus aureus [ 184 ].…”

Effect of silane coupling agent‐TiO2 on the sustained release performance of quaternary ammonium salt of chitosan shell fragrance microcapsules

“…[10][11][12][13][14][15][16] In the selection of microcapsule shell materials, due to their safety, bacteriostasis, biodegradability and biocompatibility, chitosan has attracted much attention and has been used in the process of encapsulation. [17][18][19][20][21] The polysaccharide structure will gradually oxidize, leading to a gradual decrease in the compactness of the shell material, and the core materials will diffuse out. This confirms that it has certain sustained-release properties.…”