Mechanical and flame retardant characteristics of PC/ABS composites: effect of loading co-microencapsulated flame retardant additive along with silane treated nanoclay and functionalized MWCNT as fillers

Polycarbonate and Acrylonitrile Butadiene Styrene composites have been prepared by using Co-Microencapsulated Intumescent Flame Retardant (EFR), along with Silane Treated Nanoclay and carboxylic functionalized MWCNT as nano fillers. EFR was synthesized using Ammonium Polyphosphate and charring agent (Propane Perephthalamide), encapsulated in melamine formaldehyde resin. These composites have been characterized for mechanical, thermal and flame retardancy properties. The modulus values improved while tensile strength and elongation reduced as the content of fillers increased. The composites loaded with functionalized MWCNT exhibited better performance than the Silane Treated Nanoclay loaded counterparts. With addition of 20% EFR content, reduction in tensile strength of about 66% was observed when the composites were loaded with either of the nano fillers. The tensile fractured morphology was studied using Scanning Electron Microscopy. The dispersion of nanoparticles in the composites was observed through Transmission Electron Microscopy. The optimal flame retardancy via. Cone Calorimetry was observed when 1:1 ratio of nano fillers were used, indicating synergism. Hence, a 53% reduction in peak heat release rate, enhanced thermal stability and formation of dense compact char residue were observed in the composite loaded with both the nano fillers along with 10% EFR.