Green Finishing Of Cotton Spunlace Nonwovens Via Bio-Functional Chitosan/L-Malic Acid Coating With Uv-Assisted Curing

Abstract

This study evaluated a bio-derived chitosan/L-Malic Acid (CS/L-MA) coating system for 100% cotton spunlace nonwoven fabric using two mild curing routes: drying at 40 ℃ (A2) and drying followed by UV-assisted curing at 395 nm for 4 min with TPO-L photoinitiator (B3). Untreated fabric (M0) served as the reference. FTIR-ATR spectra revealed treatment-related changes, including bands near 1 640 $cm^{−1}$ in A2 and 1 573 cm−1 in B3, together with peaks at approximately 1 733–1 734 $cm^{−1}$ that may be associated with ester-like linkages or protonated carboxyl groups. SEM observations suggested a more heterogeneous surface deposit for A2 and a comparatively more uniform fibre-surface profile for B3. The UV-assisted sample showed a slight increase in tensile strength relative to M0 and maintained a near-baseline short-range vertical wicking rate (0.80 ± 0.01 $mm·s^{−1}$ versus 0.79 ± 0.01 $mm·s^{−1}$ for M0). In contrast, the mild-dried sample (A2) exhibited a marked reduction in wicking rate (0.25 ± 0.01 $mm·s^{−1}$ ). Furthermore, B3 achieved > 99.9% bacterial reduction against Escherichia coli and Staphylococcus aureus under AATCC TM100-2019 test conditions. In contrast, both treated samples showed reduced crease recovery, and B3 exhibited a greater decrease in whiteness index. Overall, the results suggest that UV-assisted mild curing is a feasible low-temperature route for CS/L-MA functional finishing of cotton spunlace nonwovens.