Preparation of a halogen-free flame retardant and its effect on the poly(L-lactic acid) as the flame retardant material

A novel flame retardant (POCODA) was synthesized using the POC and ODA. The POCODA/APP as a synergistic flame retardant (FR) was incorporated into the poly(L-lactic acid) (PLA) to investigate effects of this synergistic FR on the thermal stability , combustion behavior and flame retardancy on the PLA. The limited oxygen index (LOI) value of the PLA-based composites gradually increased with an enhancement in the amount of the POCODA/APP. Except the PLA/5%APP, the V-0 level achieved for other composites. Both the POCODA and POCODA/APP exhibited the self-extinguishing effect on the PLA in the UL-94 test. The pHRR , THR, TSP and other combustion performance parameters of the composites reduced, compared to neat PLA, and the PLA/2%POCODA/10%APP composite exhibited the dense and continuous carbon residue after the CONE measurement and showed most excellent flame retardance. With combination of the results of the SEM , TG-IR and PY-GC/MS measurement, the flame retardant mechanism of the PLA/2%POCODA/10%APP composite was also proposed and discussed in detail.