THE PREPARATION OF DOPO-CONTAINING STARCH AND ITS APPLICATION IN FLAME RETARDANCY OF PLA

摘要

A flame-retardant poly(lactic acid)/APP biocomposites were prepared by the incorporation of bio-based phosphorous-containing starch via the melt blending.The phosphosrous-containing starch was synthesized by the grafting of maleated DOPO (DOPOMA) with starch.And the grafting content of DOPOMA was measured by titration with the value of 36.4％.Compared with the neat starch, the phosphosrous-containing starch exhibited better thermal stability and char formation by TGA.The compatibility and flame retardancy of PLA/APP composites with and without phosphosrous-containing starch were characterized by SEM, limiting oxygen index,UL-94 test, TGA, and TGA-FTIR.The results revealed that PLA/APP composites with phosphorous-containing starch exhibited enhanced compatibility, flame retardancy, thermal stability, and char residue.Especially, when the phosphorous-containing starch content was only 5wt％, the UL-94 vertical burning test showed V0 and the limiting oxygen index was 31.4％.Its thermal degradation temperature was 320 °C, char residue was about 12％.All the results suggest that phosphorous-containing starch was not only well dispersed in the PLA, but also had served as effective bio-based carbon agents for PLA.