Bark Residues Recovery of Juglans Regia. L For the Dyeing of Wool Fabrics : Development of Microwave-assisted Extraction and Dyeing Processes

Abstract

Large quantities of plant waste are rejected daily in our universe. Consequently, several researchers have proposed various ways to enhance them. One of these possible routes is recovery as a natural dye for textile use. This study aims to explore the possibility of recovering the Juglans Regia. L barks residues in natural dyeing. Hence, the extraction of a bio-dye was carried out by microwave, several parameters were studied, namely: the microwave power, the pH, and the duration. The total phenolic compounds, flavonoids, condensed and hydrolyzable tannins contents were estimated each time. Then, the colored extracts were used for dyeing wool fabrics. The Dyeing quality resulted was estimated by calculating the colorimetric coordinates (L*, a*, b*) and the color strength (K/S). Good results were obtained, with brown shades and a color strength (K/S) close to 15 was reached. The dyeing fastnesses were also checked, acceptable fastnesses to washing, rubbing and to light were obtained. Finally, the dyed and undyed wool samples were characterized by spectral Infrared analysis and a proposal of possible dyeing mechanisms was suggested.

Keywords

• juglan regia barks residues
• valorization
• microwave extraction
• natural dye
• dyeing mechanism
• phenolic compounds content