Utilization of natural and waste sources for synthesis of cellulose, chitin, and chitosan for a suitable environment.

The growing need for sustainable materials has sparked interest in natural polymers such as cellulose, chitin, and chitosan. This review explored the synthesis routes and various natural and waste-derived sources of these biopolymers. Chitin and chitosan, obtained primarily from crustaceans, insects, and microorganisms, are economically valuable due to their biodegradability and biocompatibility. Chitosan is produced through demineralization, deproteinization, and deacetylation using either chemical methods or microbial fermentation. Cellulose is extracted from agro-waste (, banana peels, rice husks) and textile residues using chemical or mechanical techniques, with processing occurring on nano to macro scales through pre-hydrolysis, bleaching, and pulping. Emphasizing synthesis conditions, environmental implications, and industrial relevance, this review aims to comprehensively understand these polymers' structural characteristics and processing pathways, offering guidance for future research and sustainable waste valorization.