A nimble strategy for enabling bioderived flame retardants with strikingly enhanced interfacial compatibility in poly (lactic acid) composites.

The utilization of bioderived flame retardants in biodegradable poly (lactic acid) (PLA) has profound practical implications for extending the widespread application of PLA composites and protecting the environment. Nevertheless, there are still certain challenges that require prompt attention, especially the ineffectiveness of bio-based flame retardants and their deterioration of the mechanical properties of PLA. This work introduced triglycidyl isocyanurate (TGIC), which has multiple epoxy functions, into the self-assembly process of phytic acid (PA) and chitosan (CS). The epoxy-modified bioderived flame retardant PA@CS-TGIC (PCT) was well dispersed in the PLA matrix and had a strong interfacial adhesion, while also TGIC had a synergistic char-forming effect. By compounding epoxy-modified ammonium polyphosphate (MAPP), 3%PCT/MAPP-PLA composites may reach a LOI value of 28.8 % and UL-94 V-0 rating. Simultaneously, the melting droplets had been considerably reduced. Tensile strength of the 3%PCT/MAPP-PLA composites was 67.0 MPa, 10.8 % higher than that of pure PLA. This work paves a new avenue for the development of PLA composites with robust mechanical and flame retardant properties.

In-situ reactive compatiblization modified poly(l-lactic acid) and poly (butylene adipate-co-terephthalate) blends with improved toughening and thermal characteristics.

Triglycidyl isocyanurate (TGIC) with multifunctional epoxy is used for reactive compatibilization of Poly (l-lactic acid) (PLLA)/Poly (butylene adipate-co-terephthalate) (PBAT) blends. Interfacial tension, FTIR and SEM results show that TGIC has greater affinity and stronger reactivity with PBAT. The mixing sequence of PLLA/PBAT/TGIC blends has a significant impact on the compatibility. The TGIC and PBAT are reactive blended first, followed by the PLLA, which is most advantageous to produce a substantial amounts of branched copolymers PLLA-g-PBAT at the interface for the (PBAT/4%T) /PLLA blend. The considerable improvement of interfacial compatibility and the thickening of interfacial layer promote the stress transfer from the matrix to the dispersed PBAT phase. In comparison to PLLA/PBAT blend, the breaking elongation of (PBAT/4%T)/PLLA blend is raised by 25.6 times up to 164.2 % and the tensile strength is enhanced up to 32.1 MPa. The present work offers valuable perspectives on how to encourage the efficient application of reactive compatibilizers with epoxy groups in polyester blends.