Construction of a hydrophobicity, phosphorus‐ and nitrogen‐containing layered double hydroxides‐based synergistic effect flame retardant for poly (lactic acid)

Abstract In this work, a synergistic effect strategy was explored for fabricating hydrophobicity, phosphorus‐ and nitrogen‐containing layered double hydroxides nanosheets (LDHs) based flame retardant (LDHs‐K@DM). This fabricating process was achieved by amination of the surface of LDHs and, subsequently, interfacial self‐assembly with high P content of diethylenetriaminpenta (methylene‐phosphonic acid) (DTPMP) and high N content of melamine (MEL). The chemical construction and thermal stabilization properties of LDHs‐K@DM were confirmed via different characterization approaches. The results revealed that LDHs‐K@DM was successfully prepared and the surface of LDHs‐K@DM was transformed into hydrophobicity with high water contact angle. Moreover, LDHs‐K@DM had better thermal stability. After that, LDHs‐K@DM was molten compounded with biobased polylactic acid (PLA). It was suggested that LDHs‐K@DM were uniformly dispersed in the PLA matrix and could accelerate the decomposition of PLA to form char residues. Most importantly, the addition of 20 wt% LDHs‐K@DM into PLA can endow the composite to achieve a desirable UL‐94 V‐0 rating and the limiting oxygen index value of 30.9%. Finally, the synergistic effect flame retardant mechanism of LDHs‐K@DM was comprehensively analyzed. This synergistic decorating strategy for preparing LDHs‐K@DM flame retardant is promising for industrial production.