Influence of boron bearing fillers on flame retardancy properties of huntite hydromagnesite filled ductile PLA biocomposites

Abstract

In this work, the flame retardancy influences of colemanite and boron oxide are investigated n huntite-hydromagnesite (HH) containing plasticized poly (lactic acid) (PLA) biocomposites. The composites are characterized using limiting oxygen index (LOI), horizontal (UL 94 HB) and vertical (UL-94 V) burning tests, mass loss calorimeter (MLC), and thermogravimetric analysis (TGA). The addition of colemanite causes enhanced fire retardancy performance with higher UL-94 V rating and LOI value and lower peak heat release rate (pHRR) value. V0 rating and the highest LOI value are observed with the addition 1 wt% colemanite. The samples get V1 rating for the loading amount of 3 and 5 wt% colemanite. When the concentration of colemanite reaches to 5 wt%, pHRR and average heat release rate (avHRR) values are lower than those of the reference sample. Addition of boron oxide causes improvement in LOI value. The highest LOI value (33.2) is observed in 5 and 10 wt% boron oxide containing samples.