Biodegradable thermoset poly(lactic acid) resin containing phosphorus: Flame retardancy, mechanical properties and its soil degradation behavior

With the growing environmental awareness, poly(lactic acid) (PLA) is regarded as one of the most promising varieties of bio-based polyesters owing to its environment-friendly and biodegradable advantages. However, poor thermal stability and flammability disadvantages limit the applications of PLA. Herein, a series of biodegradable intrinsic flame-retardant thermoset PLA resins (DMMP-M4sPLA) were designed. DMMP-M4sPLA resins exhibit excellent flame retardancy, achieving UL 94 V-0 rating and limiting oxygen index (LOI) of 28.1 %-31.7 %. Meanwhile, the cured DMMP-M4sPLA resins show a high glass transition temperature and tensile strength. In addition, the resins demonstrate full degradation with no harmful degradation products. This work provides an advanced design strategy to create bio-based and biodegraded resins with superior flame retardant and mechanical performance, holding great potentials in the fields of aviation interior, automotive, etc.