Evaluation of nanocomposites containing graphene nanoplatelets: Mechanical properties and combustion behavior

Polypropylene (PP) nanocomposites containing graphene nanoplatelets (GNPs) with different loadings were fabricated via masterbatch compounding–melt blending processing technique. Morphological studies showed that the method employed provided uniform GNPs dispersion in the matrix, orienting the nanoplatelets along the same direction the flow of matter. Enhancements of storage and Young's modulus occurred, increasing GNP content, and the improvement was more obvious when a compatibilizer, the PP‐grafted‐maleic anhydride, was introduced to achieve a better GNP dispersion and distribution within the matrix. For all the nanocomposites, even for those compatibilized, it was not possible to fully exploit the GNP toughening effect since a stiffening and embrittling effect prevailed. Thermogravimetric analysis showed that GNP incorporation has improved the thermal stability of the nanocomposites. In addition, cone calorimetry results showed that GNPs can act as intumescent flame retardant and significantly reduced the heat release rate, thus improving the flame retardancy of the PP matrix. POLYM. ENG. SCI., 59:2062–2071, 2019. © 2019 Society of Plastics Engineers