Filament keratin textiles from poultry wastes: Dyeability with α-bromoacrylamide reactive dyes for large-scale applications

The objective of this paper is to understand the dyeability of regenerated keratin textiles from chicken feathers with reactive dyes for industrial applications. Low-value poultry waste has been transformed into high quality keratin filaments and reactive dyes containing α-bromoacrylamide reactive group have been used as precursors to characterize the sorption behavior, colorfastness, and property retention of keratin textiles after dyeing. With efficient recovery of secondary structures and high disulfide crosslinkages, regenerated keratin fibers developed from waste feathers have already demonstrated excellent strength and wet stability at an affordable cost, making them highly promising for industrial applications. To characterize the sorption behavior, reactive dyes are chosen for this study to achieve high wet fastness with minimal fiber damage. The dye adsorption and fixation mechanism of reactive dyes on regenerated keratin fibers agreed well with the Langmuir isotherm model. The maximum adsorption and fixation capacity on keratin fibers were found to be 0.25–0.29 mol/kg and 0.14–0.17 mol/kg. The calculated standard affinity, enthalpy, and entropy from fixation isotherm were found to be in the range of 3.01–5.02 kJ/mol, −34.18 to −35.62 kJ/mol, and −83.76 to −86.07 J/mol·K respectively. These thermodynamic parameters obtained for regenerated keratin fiber fall in between the values for wool and silk, in descending order. Non-linear regression model with multiple terms from Crank’s diffusion equation was found to fit the kinetic data better compared to single term. Regenerated keratin fibers dyed with reactive dyes demonstrated excellent color fastness along with satisfactory strength retention after dyeing, making them suitable for both indoor and outdoor textile applications.