Dielectric investigation of some normal alcohols and diols dispersed in some polymeric matrices

A series of diols and normal alcohols were dispersed in some polymeric matrices, namely, polystyrene (PS), polyethylene (PE), and poly(methyl methacrylate) (PMMA). The dielectric properties of these systems were investigated in the frequency range of 102–105 Hz at a room temperature of 25°C. The experimental data were analyzed according to the Fröhlich equation into two relaxation processes: The first relaxation in the lower‐frequency range could be attributed to the Maxwell–Wagner effect as a result of the difference in permittivities and conductivities of the investigated systems. The second relaxation in the higher‐frequency range could be attributed to an intramolecular motion involving the rotation of various segments of the chain about the CC bond accompanied by movement of the main dipoles for either diols or alcohols. The presence of the phenyl ring in the PS matrix may hinder such rotation when compared with the other matrices. The dielectric properties were also investigated for PMMA blended with either PS or PE at different ratios before and after the addition of small quantities of ethanediol. The interaction that might be expected between PMMA and PS in the blend may affect the rotation of the ethanediol chain in the blend matrix. The dielectric data as well as the data obtained from the calculated heat of mixing show that the investigated blends are incompatible. The addition of ethanediol to such blends gives the possibility that a large number of dipoles can be impregnated into the blend matrix and the problem of phase separation could be solved.