Grafting of keratin onto O2-plasma-irradiated polypropylene fabrics for induced dyeability and durable hygroscopic properties

Abstract

Polypropylene (PP) is an inert polymer that is very difficult to dye and finish. In the current work, PP fabrics were activated by an oxygen plasma beam, followed by treatment with a renewable natural biopolymer, namely keratin, in the presence of glutardialdehyde as a crosslinker using the pad-dry-cure method. The treated PP fabric exhibited adequate hydrophilic characteristics which make it dyeable with cationic dyestuffs with excellent fastness properties. The effects of curing time and temperature on the fibers’ weight, strength, elongation, wettability, and yellowness were monitored. Fourier transform infrared (FTIR) and nuclear magnetic resonance (1H NMR) spectroscopy were used to verify the formation of polar functional groups within the chemical structure of the treated PP fabrics. The proposed method has a positive effect on some of the comfort attributes of the treated PP fabrics, such as the enhanced resistance to ultraviolet rays as well as the accumulation of electrostatic charge without deterioration in the fabrics’ inherent properties. The microscopic investigation using scanning electron microscopy demonstrated a coating of PP fabric with a layer of keratin. The induced effect was durable in terms of their wettability and dyeability, against washing for up to 20 washing cycles, indicating the formation of a fortified bond between the O2-plasma-irradiated PP fabric and keratin.