Polylactic acid is steadily gaining market share as a compostable, bio-based alternative to petroleum-based thermoplastics. However, its use in high-performance applications remains limited due to its brittleness, low heat-distortion temperature, and rapid hydrolytic and thermal oxidative breakdown. Over the past 25 years, researchers have developed various methods to address these challenges, including modifying molecular chain architecture, controlling supramolecular compatibility and crystallinity, and reinforcing macro- and nano-scale structures. This review examines these strategies across different length scales. It critically evaluates how multimodal approaches, such as chain extension, dynamic networking, compatibilization, plasticization, nanofiller integration, and fiber-reinforced blends, can deliver synergistic improvements in durability while supporting principles of the circular economy. By comparing results on mechanical, thermal, recyclability, and aging, the review also identifies research gaps, particularly in long-term aging under real-world conditions and in end-of-life sorting infrastructure. At the end of this review, a roadmap is proposed for translating laboratory breakthroughs into scalable industrial applications.
Nomadolo et al. (2026) studied this question.