Toward next-generation exotic-leather alternatives: a comparative analysis of genuine crocodile leather and its bio-based and synthetic imitations

Abstract Crocodile leather production raises ethical and environmental concerns and, unlike bovine leather, lacks quantitative performance targets for optimizing fully bio-based crocodile leather alternatives. This case study provides a preliminary characterization of representative exemplars of bio-based and synthetic crocodile leather imitations, and genuine crocodile leather, to establish a like-for-like baseline for the development of exotic-like, and fully bio-based materials. Morphological and chemical analyses showed that both synthetic and bio-based crocodile imitations are coated laminates with synthetic fabrics as reinforcing backers. Tensile tests revealed strength between 3 and 10 MPa for the synthetic laminate and about 30 MPa for both the bio-based laminate and genuine crocodile leather. Tear tests showed that genuine crocodile leather withstands forces more than seven times those of the synthetic alternative. Water-sensitivity analyses indicated that the synthetic laminate behaved as a water vapor barrier, while bio-based crocodile leather imitation showed greater water affinity, placing it in a tunable regime where bio-derived coatings can be engineered to balance water uptake and breathability. Finally, genuine crocodile leather combines a hydrophobic surface with high water and moisture uptake and the highest vapor transmission, making its mechanical performance most sensitive to humidity. Overall, this study establishes an indicative comparative benchmark for mechanical and moisture performance that can guide the optimization of fully bio-based crocodile leather alternatives.