Sustainable technique of dyeing bio-degradable polyester using henna extract

Purpose The purpose of this study is to highlight the threats related to the utilization of synthetic fibers. Volatile organic compounds, particulates and acid gases are released during the production of polyester and other synthetic textiles. Polyester is problematic solid waste material as it takes centuries to break down and hence causes microplastic pollution. Biodegradable synthetic solutions for the replacement of polyester are a sustainable business marketing these days. The naNia fiber is the breakthrough product and it is claimed a biodegradable, compostable and toxin-free polymer. Design/methodology/approach In this research, fabric constructed of naNia fiber was dyed with the extract of naturally occurring Lawsonia inermis (henna) plant leaves. The henna dye was extracted in water and ethanol using different methods, and the better extract was selected by the evaluation of ultraviolet-visible spectroscopy and phytochemical analysis. Henna with ethanol extract showed more desirable results hence it was selected to dye naNia fabric. To improve dyeability, premordanting, simultaneous mordanting and postmordanting were done using chitosan, fresh lemon extract and tannic acid, respectively. The dyed fabric samples were subjected to color strength analysis and multiple colorfastness tests. Findings The colorfastness test has shown good to excellent results. Scanning electron microscope analysis had also shown the attachment of dye molecules to the filaments. This study revealed that henna dye is appropriate to color naNia fiber even without the aid of a mordant. Originality/value For the first time, toxicant-free, biodegradable polyester (naNia) is successfully dyed with sustainable and naturally available dyes and mordants.