Synthesis of a novel polyphosphate and its application with APP in flame retardant PLA
writer：Liu T, Jing J, Zhang Y*, Fang ZP
keywords：polyphosphate, flame retardant, Polylactic acid
source：期刊
specific source：RSC Advances, 2018.2, 8: 4483-4493
Issue time：2018年
In this study, a novel phosphorus-containing flame retardant (PFRS) was synthesized through an A2+B3 type reaction of bisphenolic acid-based monomer (DPM, A2) and phosphorus oxychloride (POCl3, B3). The PLA/PFRS composites achieved LOI value of 24.3 and V2 level of UL-94 at the PFRS loading of 15wt%. When PFRS combined with ammonium polyphosphate (APP) to constitute intumescent flame retardant (IFR) systems, more significant enhancements in flame retardancy were achieved. The LOI value of PLA composite with the addition of 3.8wt% PFRS and 11.2wt% APP reached 29.7 and the PHRR decreased 46% compared with the pure PLA, and it could pass the UL-94 V0 rate as well. Furthermore, the data of cone tests, thermo gravimetric analysis and Raman spectra confirmed that a condensed phase mechanism was mainly responsible for the efficient flame retardancy of PLA/PFRS/APP systems.