Development and Characterization of a Casein‐Based Biodegradable Composite for 3D Printing Disposable Cutlery

Abstract

This research explores the potential of casein, a milk‐derived biopolymer, as a sustainable material for 3D printing disposable cutlery. A biodegradable composite combining casein, carboxymethyl cellulose (CMC), and ghee residue was developed, balancing environmental responsibility with functional performance. Physicochemical, textural, and rheological analyses revealed shear‐thinning behavior, moderate viscosity, and elastic characteristics, critical for 3D printing. The optimized sample, printed at 15 mm/s speed, 1.5 mm layer height, and 0.5% ghee residue, achieved the highest print score, with minimal deviations in diameter (10%) and area (2.58%), indicating excellent printability and shape fidelity. The material exhibited a tensile strength of 4.32 ± 0.37 MPa, Young's modulus of 314 ± 6.20 MPa, and limited elongation at break (0.133 ± 0.015%), suitable for non‐load‐bearing applications. Thermal stability was confirmed up to 338.85°C, with a crystallinity index of 42.73%. A hydrophilic surface (contact angle: 38.4°) enabled high water absorption (617.42% at pH 9) and minimal oil absorption (7.32%). The composite demonstrated rapid biodegradability, disintegrating in water within 7 days and nearly degrading in soil within 30 days. These results highlight the potential of casein‐based composites as sustainable alternatives for 3D printing biodegradable cutlery.