Development of bio‐based magnesium phosphate flame retardant for simultaneously improved flame retardancy, smoke suppression and mechanical properties of HDPE

Abstract In this article, MHPA, a novel bio‐based flame retardant, was prepared by a reaction of magnesium hydroxide (MH) and phytic acid (PA). Then, MHPA was added into high‐density polyethylene (HDPE) to prepare flame‐retardant HDPE composite. This work aims to add MHPA into HDPE to flame‐retardant HDPE composites by melt blending to significantly reduce the smoke and toxic gases produced during combustion. The limiting oxygen index (LOI) and cone calorimeter test (CCT) results show that the flame retardancy and smoke suppression of HDPE can be improved by the mixture of MHPA and MH. The LOI of HDPE/MHPA/MH was 26.3%, and its peak heat release rate (pHRR), total heat release (THR) and total smoke production (TSP) values decreased by 38.6%, 27.3%, and 65.2%, respectively, compared with pure HDPE. In addition, HDPE/MHPA/MH composites have significant tensile strength, elongation breaking strength, and tear strength because of the interface compatibility of bio‐based MHPA. Therefore, this study verified that the flame retardancy, smoke suppression, and mechanical properties of HDPE composites could be effectively improved when MHPA and MH are added to HDPE simultaneously.