Study on the fabrication of flexible polymer matrix composite using lignin isolated from coir pith waste and cellulose nanocrystals extracted from cotton waste for industrial applications

Abstract

Population growth drives resource production and consumption, with food and apparel industries generating large quantities of biomass waste. Such waste can be repurposed for various applications, including bioenergy and nanomaterials. Cotton-based textile waste offers valuable cellulosic material for upcycling, while coir pith is an underutilized resource with high lignin content. Repurposing coir pith waste offers potential benefits in soilless agriculture and bio-oil production. This study focuses on upcycling waste cotton fibers and waste coir pith into a high-strength polymer composite film., cellulose nanocrystals (CNCs), a nanomaterial derived from waste cotton fibers, are the most abundant biopolymer on Earth. CNCs have gained significant attention recently due to their exceptional mechanical properties, high aspect ratio, and biodegradability. They have been used as reinforcing agents in various polymer matrices to enhance their mechanical properties. Lignin is another biopolymer that is found in plant cell walls. It is the second most abundant biopolymer after cellulose and is known for its excellent mechanical properties, such as high stiffness and strength. Excess lignin in coir pith tends to be a recalcitrant in its biodegradation. However, recent research has shown that it can be used as a reinforcing agent in polymer composites to improve their mechanical properties. Combining CNCs and lignin in polymer matrices has been shown to produce high performance materials with enhanced mechanical, thermal, and barrier properties. The resulting materials can have potential applications in various fields, such as automotive, aerospace, construction, and packaging newline