Evaluation of flammability, thermal stability and mechanical behavior of expandable graphite-reinforced acrylonitrile–butadiene–styrene terpolymer

Abstract

Acrylonitrile-butadiene-styrene (ABS) terpolymer was loaded with expandable graphite (EG) at four different concentrations of 5%, 10%, 15% and 20% using micro-compounder followed by injection molding process. Mechanical, thermomechanical, thermal, flame retardancy, melt flow and morphological characterizations of composites were done by tensile, hardness and impact tests, dynamic mechanical analysis (DMA), thermogravimetric analysis (TGA), melt flow index (MFI) test and scanning electron microscopy (SEM), respectively. According to test results, tensile strength and storage modulus of ABS were improved with the increase in EG content. Storage modulus and glass transition temperature of ABS yielded enhancement with the inclusion of EG. However, percent elongation and impact strength values showed decreasing trend with EG additions. ABS/EG composites gave higher fire performance relative to ABS including enhancement in LOI and reduction in heat release rate. MFI test revealed that incorporation of EG with the lowest amount displayed no dramatic change for MFI value of neat ABS. EG flakes exhibited well-dispersion and exfoliated structure for all of the filling ratios as the SEM microimages of composites were examined. 15% and 20% EG containing ABS composites were remarked as the most suitable candidates among prepared composites.