Preparation and intumescently flame-retardant properties of spirocyclic pentaerythritol bisphosphorate disphosphoryl melamine organomodified montmorillonite/polylactide nanocomposite

Intumescently flame retardant polylactide (SPBDM-OMMT/PLA) nanocomposites were prepared by melt-extruding polylactide(PLA)with spirocyclic pentaerythritol bisphosphorate disphosphoryl melamine (SPBDM) and organo-modified montmorillonite (OMMT). The internal structure of the composites was probed established by XRD and TEM. The SPBDM-OMMT/PLA nanocomposites were also evaluated by thermal gravimetric analysis(TGA), limiting oxygen index(LOI) measurements and UL-94 tests. The results reveal that the uniformly dispersed OMMT clay exfoliates or intercalates in PLA matrix. The thermal stability and char yield of these nanocomposites are greatly enhanced at high temperature, and the maximum degradation temperature increases compared with those of pure PLA. The LOI value of 32% and V-0 level are achieved when 10.0% of SPBDM and 1.0% of OMMT (mass fraction) are added.