Antimicrobial chitosan finish of cotton and silk fabrics by UV-curing with 2-hydroxy-2-methylphenylpropane-1-one

The purpose of this work was to develop a textile finish based on radical UV-curing of chitosan on cotton and silk to confer antimicrobial properties. Fabrics were impregnated with a solution of 2% w chitosan in aqueous acetic acid (2% v/v) added of 2-hydroxy-2-methylphenylpropane-1-one (2% w/w with respect to chitosan) as photoinitiator and cured at room temperature by exposure to UV lamp for 60 s on both the sides. The antimicrobial activity of finished fabrics was tested according to ASTM standard test performed with Escherichia coli. Obtained results showed a strong antimicrobial activity conferred by the treatment, homogeneous on fabric surface, without affecting the hand properties of fabrics due to the low chitosan weight on (about 2%). The treatment durability to domestic laundering was tested after 5 cycles using either anionic or nonionic detergents. The antimicrobial activity resulted completely maintained after washing with a nonionic surfactant, while with anionic detergents the treatment durability was better for samples prepared with a deeper penetration of chitosan inside the fibers. The fabrics were characterized by dyeing tests, SEM and FTIR-ATR analyzes.