Influence of Flame Retardants on LLDPE-Date Pit Fiber Composites: Thermal Degradation and Tensile Properties

Linear low density polyethylene (LLDPE)-date pit composites incorporated with different flame retardants were synthesized by extrusion and casted into shape by injection moulding. Several additive type flame retardants viz. Ammonium polyphosphate (APP), Melamine phosphate (MP), Ammonium dihydrogen orthophosphate (ADOP), Diammonium hydrogen phosphate (DAHP) were added to enhance the flame retarding behaviour of composites. The thermal analysis and mechanical properties of composites have also been investigated. Thermogravimetric analysis (TGA) revealed a two step degradation mechanism of all the blends. The kinetic parameters such as activation energy and differential conversion function f(alpha) were evaluated using three different non isothermal methods based on the iso conversional plots: Friedman (FM), Ozawa-Flynn-Wall (OFW) and Coats-Redfern (Modified). The average value of activation energy of thermal degradation of blends evaluated using Friedman method; was used to depict the actual mechanism of degradation by fabricating the Criado's master plot. Addition of any kind of flame retardant led to an improvement in both tensile as well as flexural strength of composites. According to the results of Limiting Oxygen Index (LOI) and UL-94 testing, addition of APP led to the significant improvement in the flame retardancy of LLDPE composites.