Green synthesis of lanthanum oxide catalyst for the polymerization of lactide monomer: A sustainable approach for biodegradable plastic production

Abstract Polylactic acid (PLA) is a good alternative to shift from petroleum‐based to biodegradable synthetics. However, its implementation faces barriers due to inefficient synthesis involving hazardous organometallic complexes and toxic solvents, making green plastic production environmentally unfriendly. By addressing this discrepancy, we propose the utilization of lanthanum oxide as a robust, heterogeneous catalyst for the solvent‐free, green synthesis of PLA. The catalytic framework was synthesized and characterized using XRD for phase crystallinity SEM for surface topography, and BET isotherms for surface area and porosity of particles. Characterization confirmed the presence of a catalyst with a high active‐site density and crystalline boundaries. In the ring‐opening polymerization (ROP) of lactide, the showed exceptional catalytic activity. By optimizing the temperature, time, and catalyst‐to‐monomer ratios, we synthesized PLA with a high degree of polymerization. The polymer exhibited a high molecular weight and narrow molecular weight distribution, surpassing those of traditional transition metal catalysts. Kinetic studies showed that polymerization occurs through coordination‐insertion mechanism, consistent with lanthanide catalysts electronic configuration where enables a nucleophilic attack on lactide. Activation energy measurements confirmed surface reduces energy barriers, accelerating reactions while maintaining structural integrity. functions as an efficient and sustainable catalyst that eliminates harmful reagents, making La‐based heterostructures viable for industrial PLA production. Future research should examine the recyclability and stability of catalysts in continuous‐flow reactors for large‐scale biopolymer manufacturing.