Surface modification of polyamide 6.6 fibers by enzymatic hydrolysis

- Alcalase 2.4 L was used for the surface hydrolysis of polyamide 6.6 fabrics.
- PA modification was confirmed by spectroscopic, analytical and dyeability analyses.
- The surface of PA fabric was modified superficially maintaining its bulk properties.

Synthetic fibers are used extensively in textile industry, however, their high hydrophobicity is a drawback that needs to be considered. The decrease of hydrophobicity can be achieved via a “green” root using enzymes as biocatalysts. In this study, the enzymatic surface modification of polyamide (PA) 6.6 fabric was studied with the use of the commercial protease Alcalase 2.4 L at optimal conditions. The modified fabrics were studied via dyeing parameters K/S and ΔΕ values. For treatment at 40-60 °C and pH 8 ΔE was found to be approximately 14 and K/S was 1.24-fold increased. Additionally, the enzymatic surface modification of PA textile was justified using different spectroscopy techniques, such as FTIR-ATR and XPS. FTIR-ATR indicated alterations of CO and NH band intensities, while via XPS, there proved to be differences in relative intensities of carbon component peaks. Finally, thermogravimetric and mechanical tests were also conducted to prove the non-degradation of the properties of the bulk material. In conclusion, the investigated enzymatic process increased the hydrophilicity with 2.7-fold increased water absorbency and 1.24-fold enhanced color strength of PA textiles, while maintaining the thermal and mechanical properties of the bulk synthetic material.

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