Akademik Məlumat İdarəetmə Sistemi
Bulletin of the Georgian National Academy of Sciences, vol.14, no.2, pp.36-41, 2020 (Scopus)
For the development of PTFE-based nanocomposites with the regulated technological mechanical and parameters it is necessary to reveal the correlation between their structural and dynamical-mechanical properties. The researches in this direction were performed using a low-frequency internal friction technique. The behavior of the elastic/inelastic properties of PTFE-based nanocomposite material filled with the optimal (7.5 wt%) concentration of Fe atom cluster-doped carbon nanotubes (CNTs), depending on high amplitude cycling deformation and post-deformation annealing was investigated using amplitude-independent (AIIF) and amplitude-dependent (ADIF) internal friction measurements. The characteristics of dynamical-mechanical strengthening of the Fe cluster doped PTFE-based polymeric materials were determined for the first time, and the possible mechanisms of strengthening have been analyzed. It was shown that high-amplitude cyclic deformation leads to a considerable reduction in activation energy (H, kcal/mole) of β(crystalline) and α(amorphous) relaxation processes, the magnitude of critical amplitudes (εc) of microplastic deformation beginning and shear modulus (G ~ f2) in comparison to those for the initial sample before cyclic deformation. It was also found that the post-deformation annealing of the cyclically deformed sample at 150˚C/30 min ensures a complete restoration of the above parameters to the values exceeding those for the initial sample.