Biohydrolysis of nylon 6,6 fiber with different proteolytic enzymes

In recent years, the textile industry must go towards sustainable technologies and developing environmentally safer methods for textiles processing. One way is the processing with enzymatic system, rather than conventional chemical methods. The aim of this work was to investigate the changes induced on nylon 6,6 fiber by enzymatic system using different proteolytic enzymes. Technical measurements were studied including Fourier-transform infrared spectroscopy, scanning electron microscopy, thermal, dyeability, and fastness properties. For this purpose, nylon 6,6 fabrics were first treated separately with different concentrations of four protease enzymes. The dyeing process was then carried out on the treated fabrics with two reactive and acid dyes. The intensity of major peaks in FTIR spectra of the protease treated samples is in favor of chemical changes of the polypeptide functional groups in fabric. Thermal studies also show significant decrease in thermal degradation temperature of the treated polymer. Reactive and acid dyes showed higher dyebath exhaustion on the enzyme treated samples compared to raw material. The results of color measurements showed that the more concentration of enzyme used, the darker the color of dyed sample is. Interesting results were obtained in the studied topic.