Flame retardant and thermal behavior of polylactide/expandable graphite composites

In this article expandable graphite was used to produce fire retardant biobased polylactide. For this purpose, PLA blends with addition of 1, 5 or 10 wt. % of expandable graphite intercalated with sulphuric acid (GR) were obtained using co-rotating twin screw extruder. Thermal stability and flammability of prepared samples were examined by thermogravimetric analysis (TGA), cone calorimeter measurements and UL 94 test. Flammability UL-94 test shows the highest V-0 ranking from 5 % graphite loading, whereas 10 % is required for sensible decrease of rate of combustion in cone calorimeter forced combustion test.