Polyvinyl pyrrolidone/polyvinyl alcohol (PVP/PVA) and polyvinyl pyrrolidone/starch (PVP/St) blends were prepared with different compositions. The compatibility studies indicate that PVP/PVA is compatible while PVP/St is incompatible. The addition of glycerol and glutaraldehyde can improve to some extent the phase separation behavior between PVP and St. The permittivity ε′ and the dielectric loss ε″ were measured in the frequency range 0.01 Hz up to 10 MHz and temperatures from 30 up to 90°C. It is found that the blend ratio (50/50) of both investigated systems is preferable for insulation purposes in comparable with the other blends under investigation. The data of the loss electric modulus M ″ was calculated from the dielectric parameters ε′ and ε″and analyzed into three relaxation mechanisms ascribing the cooperative motion of the main and side chains τ 1 (αβ), the side chain motion τ 2 (β) and the segmental motion of the groups attached to the side chains τ 3 (βγ). The activation energy corresponds to the second relaxation process Δ H 2 was calculated using Arrhenius equation and found to be in the range which justifies the presumption of β‐relaxation process.
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El-Houssiny et al. (2011) studied this question.
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