Sustainable cellulose-reinforced polybutylene succinate biocomposites: Fabrication, thermal stability, mechanical properties, and biodegradability evaluation

Abstract

The increasing environmental burden of petroleum-based plastics necessitates the development of biodegradable, renewable alternatives that balance functional performance with ecological compatibility. Poly(butylene succinate) (PBS) is a promising biodegradable polymer; however, its high cost and moderate stiffness limit its broader application. Although extensive research exists on natural fiber-reinforced biocomposites, the potential of false banana (Ensete ventricosum) fiber, an abundant, cellulose-rich agricultural residue, remains unexploited. This study develops sustainable PBS biocomposites reinforced with cellulose derived from false banana fiber and evaluates their microstructural, mechanical, thermal, and biodegradation behavior. The cellulose sheet was extracted from false banana fiber through alkali and bleaching treatments to enhance purity, surface reactivity, and interfacial compatibility with the polymer matrix. The extracted cellulose sheets were hot-pressed with PBS films at fiber loadings between 27 and 60 wt%. The biocomposite (27%-C/PBS) exhibited a significant improvement in tensile strength (20.94 MPa) and modulus (1578.9 MPa) compared with neat PBS (18.9 MPa and 116 MPa, respectively), attributed to effective stress transfer and strong matrix-fiber bonding confirmed by Scanning Electron Microscope (SEM). Thermogravimetric analysis revealed improved thermal stability with a degradation onset near 304°C of the false banana derived cellulose reinforced/PBS biocomposite. Biodegradation behavior of 46%-C/PBS composite under controlled composting (ISO 14855-2) achieved 67% mineralization within 50 days, showing complete microbial assimilation, enhanced biodegradability, and environmental compatibility after its service life. The mechanical deterioration correlated with CO₂ evolution, confirming coupled structural and biochemical decomposition. This study demonstrates the effective valorization of false banana–derived cellulose sheets as efficient reinforcement for PBS, enabling a unique balance between mechanical enhancement and controlled biodegradability within a single biodegradable composite material. These biocomposites are suitable for biodegradable packaging materials, lightweight disposable products, consumer goods, agricultural mulch films, and other short-life consumer applications where mechanical integrity during use and rapid end-of-life biodegradation. The findings provide a sustainable pathway for valorizing agricultural residues, advancing circular bioeconomy principles, sustainable materials engineering, and mitigating the environmental footprint of synthetic polymers. • Purified false-banana cellulose improved interfacial compatibility with PBS. • Fiber purity and adhesion influenced multi-stage thermal degradation. • False-banana-cellulose/PBS biocomposite achieved 67% mineralization in 50 days (ISO 14855–2). • CO₂ evolution of the correlated with mechanical loss, confirming true biodegradation. • Cellulose accelerated PBS degradation through enhanced moisture uptake and microbial access. • Composite offers strong performance and rapid end-of-life compostability.