Investigation of free volume of oriented electrical conducting polymer composites by spin probe method

The spine probe method based on electron spin resonance (ESR) is used for investigation of free volume of the oriented polyvinyl alcohol films filled with high dispersive carbon black. After introduction of nitroxide stable radicals by diffusion to oriented with different degree polymer films the samples were tested by noted method via definition of the measuring of correlation times of rotation of stable radicals around their axes. It is established that the lower is free radicals concentration and their correlation time in local regions of the films, the higher is the orientation (stretching) degree of the films, which is directly connected with the volume of micro-empties in the polymer matrix. These phenomena correlate with the analogical ones in the same polymer containing high dispersive electrical conducting filler (carbon black). In this case the diffusion of free radicals to the polymer matrix is more difficult than in pure polymer. The values of correlation time and diffusion coefficients of the stable radicals decrease because of additive interactions of these radicals with the filler particles. (author)