Disclinations and fractons of Cosserat elasticity in isotactic polypropylene doped with graphene and nanographite particles

Small-angle neutron scattering, dielectric spectroscopy, and dynamic mechanical analysis data are reported for composites of isotactic polypropylene (IPP) with graphene nanoparticles (GNP) and nanographite. In various samples, the volume of the IPP matrix with a high degree of crystallinity contains GNP with concentrations of 0.7 and 1.8 wt% and nanographite with concentrations of 1.5 and 3.6 wt%. For these composite systems, we applied a model of the evolution of linear disclination defects, which determines the morphology of nanosized aggregates of GNP and nanographite formed in the IPP volume. Using the theory of micropolar elasticity, or the Cosserat theory (Cosserat, Cosserat) with the fracton mechanism of the first type, correlated with the evolution of disclinations, we performed numerical estimates of the temperature and concentration dependencies of the elasticity and thermodynamic characteristics in the framework of the Monte Carlo algorithm on a dual lattice in the basis of lattice defects.