Advanced Green Materials: Sustainable Cellulose–Lignin Composite Films Prepared via Ionic Liquid Processing

The article presents the preparation method of a green composite material composed of cellulose and lignin using an ionic liquid as a solvent. In the process, cellulose and lignin are dissolved in the ionic liquid and subsequently regenerated into a composite film via coagulation in ethanol/water bath. The research focused on evaluating the mechanical properties of the resulting composite, which exhibited a high tensile strength exceeding 100 MPa, demonstrating its robustness and potential for various applications. Importantly, the simultaneous integration of lignin enabled a favorable balance between high mechanical strength and enhanced biodegradability, addressing a common trade-off in sustainable materials. Additionally, the biodegradation behavior of the composite in soil was investigated, showing that it gradually decomposes, making it environmentally friendly. Toxicity tests on soil bacteria indicated that the composite does not adversely affect microbial activity, supporting its suitability for ecological use. Furthermore, the gas permeability and water vapor transmission of the composite film was assessed, providing insight into its barrier properties. Overall, the study highlights the potential of cellulose-lignin composites produced via ionic liquids as sustainable and biodegradable materials with promising mechanical and environmental properties.