Toughening and Mechanical Properties of Epoxy Modified with Block Co-polymers and MWCNTs

The objective of this work was to systematically develop and understand novel polymeric hybrid nanocomposites that include block copolymers (BCP) with tailored morphologies in order to generate high toughness. Furthermore, rigid fillers in the form of multi-walled carbon nanotubes (MWCNT) were added systematically together with block copolymers to study the combined effect of rigid nanofillers and more ductile BCP particles. The resulting matrix was extensively and carefully characterized by standard methods. This included thorough characterization of mechanical, fracture mechanical and thermal properties. Results show that both fracture toughness, KIc, and critical energy release rate, GIc, were increased linearly to a maximum of 2.10 MPa.m1/2 and 1.46 kJ/m2 respectively by the addition of 12 wt. % BCP. Fractography studies reveal toughening mechanisms of the nanocomposites that were identified as both the cavitation of spherical micelles and enhanced plastic deformation and furthermore fiber pull-out in the case of hybrid nanocomposites.