Combustion and Thermal Properties of Polylactidewith an Effective Phosphate-Containing Flame-Retardant Oligomer

摘要

A phosphate-polyether copolymer poly (polyethylene glycol spirocyclic pentaerythritol bisphosphate) (PPGPB) has been synthesized and its structure was characterized by Fourier transformed infrared spectrometry (FTIR) and nuclear magnetic resonance (~1HNMR). A series of polylactide (PLA)based flame retardant composites containing PPGPB were prepared by melt blending. The combustion properties of PLA/PPGPB composites were evaluated through UL-94 tests and microscale combustion calorimetry (MCC) experiments. It is shown that PPGPB significantly improved the flame retardancy of PLA and only 5wt% additive allowed the composites to achieve UL-94 V-0. The possible flame retardance mechanism of PPGPB in PLA was substantiated by scanning electron microscopy (SEM) and in situ FTIR. In addition, thermogravimeric analysis (TGA) showed the weight loss rate was decreased by introduction of PPGPB, and it is found from the differential scanning calorimetry (DSC) results that PPGPB can facilitate the crystallization of PLA.