Flame retardant poly(lactic acid) biocomposites reinforced by recycled wool fibers – Thermal and mechanical properties

摘要

The inherently poor flame retardancy and comparatively low tensile strength of poly(lactic acid) (PLA) have limitedits wide adoption as alternative ‘green’ engineering plastic in many fields. This manuscript reports the synthesis of anew phosphorus flame retardant – phenylphosphonic 3(2-aminobenzothiazole) (P-TAB) and its combination with recycledshort wool fibers (WF) for improving the flame retardancy and the mechanical properties of PLA. Fourier transform infrared(FTIR), 1H, and 13C nuclear magnetic resonance (NMR) spectra proved that P-TAB was effectively synthesized. Considerablereductions in heat release rate, total heat released, CO and CO2 produced were attained with 3 wt% P-TAB and various WFloadings. The fire performance index (FPI), and fire growth index (FGI) improved by 38.2 and 48.1% respectively. Thecomposite achieved a V-0 rating at 20 wt% WF loading and an LOI value of 28.5%. TG-IR results showed substantial reductionsin evolved gaseous products. The tensile strength and Young’s modulus improved significantly with the increasingcontent of WF in the composite.