Biodegradable films developed from waste bovine hide as a sustainable alternative to synthetic plastic bags

Biodegradable plastic is a major area of research focused on replacing synthetic plastic, particularly plastic bags, to promote sustainability and environmental safety. This study developed two biodegradable films: one from 100% collagen (C-film) and another with added plasticizers (CPG-film). The collagen protein, the films' raw material, was extracted from bovine hide waste at room temperature. The study comprehensively investigated the physical, structural, and functional properties of both films and a synthetic plastic film, including thickness, tensile strength, water absorbency, hydrophilicity, burning properties, differential scanning calorimetry, thermogravimetric analysis, biodegradability, and color. The thickness and tensile strength of C-film and CPG-film were 65.5 ± 3.7 μm and 86 ± 4.5 μm, and 19.30 MPa and 12.44 MPa, respectively. Both films were hydrophilic, shrank when exposed to fire, and were biodegradable. The hydrophilic nature of these films may pose challenges in wet conditions, although they were not readily water-soluble in initial exposure. The pore sizes of the films were 1.27 μm for the C-film and 75.1 nm for the CPG-film, making them limitedly permeable to air and water, whereas synthetic plastic bags are typically impermeable. In contrast to synthetic plastic bags that persist in the environment for hundreds of years, these biodegradable films degrade in nature within one month. This study contributes to efforts to reduce such hazards by introducing newly developed collagen-based films as a potential sustainable alternative whose use and disposal in the environment are safe and pollution-free, and providing a comprehensive comparative evaluation against synthetic plastics to assess their potential, advantages, and limitations as biodegradable alternatives.