Static and Dynamical Elastic Modules of Nanocomposites Polypropylene, Teflon and Multiwalled Carbon Nanotubes

The mechanical properties of nanocomposites based on polypropylene and Teflon with multi-walled carbon nanotubes (MWCNTs) were investigated. In this study, the absolute value of the elastic modulus (E), elasticity limit (σ_E), anelasticity limit (σ_0.2), and ultimate stress limit (σ_S) of nanocomposites based on polypropylene (PP) with 5 %, 0.5 %, and 0.1 % MWCNTs were determined. The influence of ultrasonic deformation (ε_US) on the mechanical properties of nanocomposites based on polypropylene, teflon, and MWCNTs was also examined. A key factor in the modification of composite polymeric materials is the degree of adhesion at the interface, which is determined by the interaction of macromolecules with multi-walled carbon nanotubes. Since aromatic groups in various families of free monomers act as effective radical traps, they enable interaction with MWCNTs. This interaction, due to covalent bonding, leads to the fixation of polymer chains on nanotubes and the migration of radicals to the traps. The correlation between the crystalline and amorphous components of polymer macromolecules interacting with rigid MWCNTs influences the elastic and inelastic characteristics of the nanocomposites. Multi-walled carbon nanotubes have a highly disordered structure, whereas strictly ordered crystals are idealized objects. One of the methods to deliberately modify the properties of MWCNTs for nanoelectronics applications is the introduction of foreign element impurities. An increase in the crystalline degree of nanocomposites with rising MWCNT concentration, along with nanotube filling of the polymer matrix, results in a reduction of the well-organized phase content. The results of this work are important for understanding and predicting the properties of composite materials based on polymer matrices with carbon fillers.