关键词: 功能性纺织品, 抗菌性能, 阻燃性能, 棉织物, 羧甲基壳聚糖, 氧化海藻酸钠, 功能整理, 整理剂

Abstract:

Objective Cotton fabrics, despite their comfort and versatility, inherently suffer from rapid bacterial proliferation, leading to unpleasant odor, discoloration, and potential health risks, especially in close-to-skin applications. Simultaneously, their inherent high flammability poses significant safety concerns, limiting wider adoption in protective clothing and furnishings. To address these widespread issues, this research aimed to achieve a dual-functional antimicrobial and flame-retardant finishing using natural bio-polymers. The approach leverages the synergistic effect of carboxymethyl chitosan (CMC) and oxidized sodium alginate (OSA) through esterification and Schiff base reactions to graft these biopolymers onto the cotton matrix.

Method Carboxymethyl chitosan (CMC) was used to finish cotton fabrics via a pad-dry-cure process to impart antimicrobial properties. Oxidized sodium alginate (OSA) was subsequently grafted onto the CMC-finished fabrics through Schiff base reaction to confer flame retardancy. The influence of hydrochloric acid concentration and temperature during the antimicrobial finishing process, and the OSA concentration and temperature during the flame-retardant finishing process were evaluated. The orthogonal experimental design was employed to optimize finishing parameters by assessing the primary factors governing the antibacterial and flame-retardant performance of the finished cotton textiles. This systematic approach effectively identified optimal treatment conditions, minimizing experimental runs. The treated cotton fabrics were characterized using various analytical techniques. SEM was utilized for surface morphology and deposition confirmation. A fabric flame retardancy tester evaluated the flame-retardant effect, while thermogravimetric analysis (TGA) analyzed the thermal decomposition behavior and char formation. Mechanical properties (bending rigidity, bursting strength) and air permeability were assessed for comfort and durability.

Results Optimal antimicrobial treatment was achieved with a hydrochloric acid concentration of 0.3 mol/L at 70 ℃. Flame-retardant performance was maximized using 1% OSA at 80 ℃. Under these optimized conditions, the treated cotton fabrics demonstrated an antibacterial efficacy exceeding 99% against Escherichia coli. The horizontal burning rate of the treated fabrics was significantly decreased compared to the untreated control, with minimal impact on bursting strength and bending rigidity. Thermogravimetric analysis revealed an elevation in the initial decomposition temperature of the treated fabrics from 260 ℃ to 277 ℃, and an increase in char residue from 6.5% to 14.3%. The orthogonal experiment revealed that the horizontal burning rate of CMC-OSA treated cotton fabrics was reduced by nearly 50%, which enhanced the thermal stability of the fabrics to some extent while preserving good softness. However, the breathability of the treated fabrics was somewhat diminished.

Conclusion This study successfully demonstrated a synergistic approach to impart both antimicrobial and flame-retardant functionalities to cotton textiles utilizing the biopolymers CMC and OSA. Esterification and Schiff base reactions facilitated the effective grafting of the biopolymers, resulting in a durable, dual-functional textile. The optimized processes offer a sustainable and efficient strategy for producing multi-functional textiles. While a modest reduction in air permeability and bursting strength were observed in the finished textiles, these properties remained within acceptable performance thresholds. Future research should focus on elucidating the synergistic mechanism of CMC/OSA, further optimizing the process to improve both antimicrobial and flame-retardant performance while addressing the reduction in fabric mechanical properties and air permeability. Durability assessments tailored to specific application scenarios are also warranted to develop environmentally friendly, functionally finished cotton textiles with practical value.

Key words: functional textiles, antibacterial property, flame retardancy, cotton fabric, carboxymethyl chitosan, oxidized sodium alginate, functional finising, finishing agent