Synergistic mechano-chemical pretreatment of bagasse: enhancing levulinic acid production and high-performance packaging materials generation

The recalcitrant structure of lignocellulosic biomass, a sustainable feedstock for biorefineries, necessitates effective pretreatment strategies to fractionate it into functional components. This study presented an integrated pretreatment strategy combining mechanical and ionic liquid 1-butyl-3-methylimidazole chloroaluminate ([BMIM][AlCl₄])-lactic acid (LA) treatments to valorize bagasse. High-intensity mechanical treatments, such as ball milling (BM), significantly reduced cellulose crystallinity, improving the substrate’s accessibility for subsequent [BMIM][AlCl₄]-LA pretreatment. The combined pretreatment greatly enhanced lignin removal, and preserved cellulose with higher levulinic acid yields compared to untreated biomass. Regenerated lignin nanoparticles, particularly from BM pretreatment, demonstrated excellent interfacial compatibility in polyvinyl alcohol (PVA) films, enhancing UV-blocking, hydrophobicity, and mechanical strength retention, while minimizing color distortion, highlights lignin’s potential as a multifunctional additive in biodegradable packaging. Particle size-dependent analyses revealed a strong correlation between reduced lignin size and improved film performance, attributed to better dispersion and exposure of functional groups. Overall, this study demonstrates the potential of an integrated mechanical-chemical pretreatment strategy for optimizing lignocellulose valorization.