Synthesis of a deoxybenzoin derivative and its use as a flame retardant in poly(trimethylene terephthalate)

ABSTRACT A Friedel–Crafts acylation reaction was used to synthesize a deoxybenzoin derivative named bis[2,6‐dimethyl‐4‐(2‐phenyl acetyl)phenyl]phenyl phosphonate (BDPP), which could be used as a flame‐retardant additive in poly(trimethylene terephthalate) (PTT) resin. The limited oxygen index and cone calorimetry tests indicated that the introduction of 5 wt % BDPP significantly improved the flame‐retardant properties of PTT through a synergistic char‐formation mechanism in the condensed phase and a flame‐inhibition mechanism in the gas phase. The PTT–BDPP blend also demonstrated an evident reduction in the melt viscosity but a superior melt stability in comparison to the neat PTT. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018, 135, 45904.