Eco-Finishing of Cotton with Chitosan and Giant Goldenrod (Solidago gigantea Aiton) Aqueous Extract for Development of Antioxidant and UV Protective Textiles

Abstract

Giant goldenrod (S. gigantea Aiton) is considered an invasive weed in Europe, Asia, Australia, and New Zealand. In this research, the untreated and chitosan-treated cotton fabrics were functionalized with goldenrod inflorescences aqueous extract, at room temperature and 95°C. Zeta potential of fabrics was determined as a function of pH and the results showed an increased isoelectric point from 2.50 to 5.25 and amphoteric character of the chitosan-treated sample. The antioxidant activity (AA) of extract and functionalized fabrics was determined using DPPH analysis, while color and ultraviolet protection factor (UPF) were determined spectroscopically before and after wash and lightfastness testing. The chitosan pretreatment and dyeing of cotton at higher temperature increased AA (from 41.19 ± 0.28 to 56.08 ± 0.25), UPF (from 33.05 to 51.59) and color strength (K/S) (from 1.74 to 2.21), providing dyed cotton with excellent UV protection and a free radical inhibition activity. The samples had good wash fastness in terms of color (ΔEab* < 1), but not in terms of UV protection (UPF value decreased after washing to 23.47). The overall lightfastness was good to excellent (the UPF values of chitosan and dyed samples did not change much after lightfastness test (UPF = 51.75).

Keywords

• goldenrod
• invasive plant
• eco-functionalisation
• cotton
• antioxidant activity
• uv protection