PLA/LDPE Blends for Synergies in Performance and Biodegradability: A Critical Perspective on the Potential for Practical Interim Commodity Biodegradable Materials

This review paper provides a critical analysis of the biodegradability and biodegradation processes of polylactic acid (PLA), low‐density polyethylene (LDPE), and their blends, focusing on current advancements and challenges in the field. We begin by examining the intrinsic properties of PLA and LDPE that influence their degradation, followed by an exploration of the various biodegradation methods employed for these polymers. Special attention is given to the oxo‐degradation of LDPE, a pretreatment process that facilitates its subsequent biodegradation. We then delve into the increasing research surrounding PLA/LDPE blends, assessing their potential as biodegradable materials. The paper synthesizes recent scientific findings, compares contradictory results across studies, and critically distinguishes true biodegradation from abiotic degradation, disintegration, and fragmentation when evaluating the evidence base. A central conclusion of this review is that, outside industrial composting conditions, the real‐world biodegradability of PLA/LDPE blends remains uncertain, particularly for the LDPE fraction, and that reported “biodegradation” in many studies is largely attributable to the PLA, thermoplastic starch (TPS), or mineral‐filler components of ternary systems rather than to the polyethylene itself. The review closes with future research directions, including standardized end‐of‐life testing and lifecycle assessment, that could enhance the biodegradability and sustainability credentials of PLA, LDPE, and their blends. This comprehensive review serves as a valuable resource for researchers and industry professionals seeking to develop more sustainable plastic alternatives.