Cellulosic Textile Materials Functionalization with Formic Acid and Improvement of their Properties

Abstract

Formic acid, commonly used in bioprocesses of cellulosic polymeric materials, has been considered for the treatment of cellulose-based textile. Therefore, different concentrations of formic acid (10, 20, 30, 40, and 50 g L-1) were used to treat cotton (CO) and viscose (CV) fabrics to improve their properties. Weight variation, tensile strength, stiffness, drape coefficient, crease recovery angle, and vertical wicking of the treated substrates were assessed. Fourier transform infrared spectroscopy attenuated total reflection (FTIR-ATR) analysis confirmed the acid hydrolysis process of the cellulosic substrates treated with formic acid solutions. Formic acid solutions with concentrations equal to 30 g L-1 and 40 g L-1 are the most adequate to treat the CV and CO fabrics, respectively. In addition, the fabrics treated under optimal conditions were dyed with the reactive dye Levafix Blue CA. The dyeing properties were assessed through colour absorption coefficient and scattering coefficient (K/S) values. A clear improvement in the fastness and dyeing performance of the treated substrates was observed. Finally, the antibacterial properties of the treated substrates were evaluated, for the bacteria Escherichia coli and Staphylococcus aureus. It was found that only cotton substrates treated with a 40 g L-1 formic acid solution could be classified as weak decontaminants against S. aureus bacteria.