Balancing Flame Retardancy and Toughness in Polylactic Acid: Strategies, Insights, and Future Possibilities

ABSTRACT Polylactic acid (PLA) is a leading bioplastic due to its biodegradability, renewability, and minimal environmental impact. However, its inherent brittleness and poor flame retardancy limit its application in demanding industries requiring both mechanical strength and fire safety. This review explores advancements in strategies for enhancing the flame retardancy and toughness of PLA while maintaining its sustainability. Synergistic approaches, such as combining phosphorus‐nitrogen flame retardant (FR) systems with compatibilizers and toughening agents, have shown potential to achieve balanced performance. The incorporation of impact modifiers and optimized additive formulations has further improved flexibility and durability without compromising eco‐friendly attributes. Despite these advances, challenges persist, including the need for better compatibility of additives, scalability in processing, and ensuring the environmental safety of FRs and toughening agents. This review underscores the importance of tailoring multifunctional systems to overcome these challenges, highlighting the promise of fully biodegradable, nontoxic solutions that align with PLA's ecological goals. Future research should focus on integrating FR and toughening strategies to meet diverse performance requirements. By leveraging multidisciplinary collaboration, PLA can evolve into a versatile material, addressing current limitations and contributing to a more sustainable future in packaging, automotive, and other high‐demand applications.