Investigating carbon-black-filled polymer composites' brittleness

In this study, an attempt is made to quantify the brittleness in semicrystalline ethylene-co-butyl acrylate copolymer samples reinforced by carbon black (CB) nanoparticles. A series of samples with different CB volume fractions are investigated at ambient conditions. Two approaches are used to quantify the brittleness parameter. On the one hand, we consider brittleness of polymeric materials quantitatively defined by Brostow and Hagg Lobland. On the other hand, Lawn and Marshall's approach based on the resistance of a material to both deformation and fracture is adopted. The ability of these two approaches to provide an estimation of the brittleness index is studied. The results also show the correlation of the brittleness index to the indentation properties, i.e., hardness and Young's modulus. Additionally, we discuss the commonality between the bulk mechanical properties, i.e., hardening modulus and frictional forces, and brittleness.