Physico-chemical and dielectric characterization of polypyrrole clay composite

Abstract

In this study, we report on the chemical and dielectric properties of polypyrrole (PPy) clay composite. The in situ polymerization has been carried out in an aqueous solution using ammonium persulfate (APS) as oxidant. Molar ratio of Pyrrole (Py) to interlayer clay cation was fixed to 4 and that of APS to Py (R) was varied in the range of 0.25–4.00. It was shown that both the chemical and dielectric behaviors were affected by the variation of (R). XRD results showed an intercalated structure of PPy for a value of R corresponding to 0.25. Above this value, the basal distance (d001) was found to be around 1.3 nm, implying that PPy is essentially located at the surface of Montmorillonite (MMT). From FTIR spectroscopy, it was found that for R = 4, PPy was degraded, resulting in a decrease of the degree of polymerization and conductivity. For all samples the AC conductivity was found to be constant until 2 × 105 Hz but increased steeply above this value. The highest conductivity was found to be around 3.95 10−3 S.cm−1 for R = 1. The composite exhibited very large values of ε′ and ε″ at a low frequency, these values decreased with the increase of frequency. Curves of imaginary electric modulus (M″) exhibited a frequency peak due to the process of relaxation time of conductivity (τ = 6.9410−8 s) for R = 1. POLYM. COMPOS., 38:2043–2051, 2017. © 2015 Society of Plastics Engineers