Dielectric relaxation of fullerene C60-containing nanocomposites based on poly(phenylene oxide)

Molecular mobility of nanocomposites based on poly(phenylene oxide) (PPO) containing 1, 2, 4 and 8 wt% of C-60 fullerenes was studied by dielectric spectroscopy. In all samples, two relaxation processes were present and caused by polarization of the single polar -O- group located between phenyl rings. This polarization includes two stages With the first stage (occurring in the glassy state) is caused by rotation of phenyl rings and the adjacent polar -O- groups by small angles that results in the local beta process. The second stage (occurring at temperatures exceeding the glass transition temperature T-g) involves segmental mobility and leads to emergence of the a process. Molecular mobility in the region of the beta process varies slightly with C-60 concentration. In the case of the a process, molecular mobility changes non-monotonically with increasing fullerene concentration.