chitin

Chitin is a natural biopolymer—a polysaccharide structurally similar to cellulose—derived primarily from the exoskeletons of arthropods (crustaceans, insects) and fungal cell walls. It is a renewable, biodegradable material that combines moderate mechanical strength with light weight, making it attractive for applications requiring sustainability and biocompatibility. Engineers select chitin and its derivatives (particularly chitosan) over synthetic polymers in biomedical, environmental remediation, and food processing contexts where degradability, non-toxicity, and antimicrobial properties are critical; it also serves as a precursor for advanced composites and functional films.