Effect of a phosphorus-containing oligomer on flame-retardant, rheological and mechanical properties of poly (lactic acid)

A new flame retardant poly (1, 2-propanediol 2-carboxyethyl phenyl phosphinate) (PCPP) was synthesized with 2-carboxyethyl phenylphosphinic acid (CEPPA) and 1, 2-propanediol (PD). The structure of PCPP has been studied by FTIR and 13C NMR spectra. A series of poly (lactic acid) (PLA) blends were prepared by direct melt compounding with PCPP as flame retardant and plasticizer. And it was proved to be an effective flame retardant for the PLA as evidenced by increasing limiting oxygen index (LOI) value, which increasing from 19.7 for pristine PLA to 28.2 for the PLA with 10 wt% PCPP. Additionally, the introduction of PCPP also amended the rheological and mechanical properties of the PLA. When the content of PCPP in the composites was up to 15 wt%, the flame retardant and the mechanical properties were improved simultaneously.