Synthesis, characterization and some physicochemical properties of polypyrrole/halloysite composites

Pyrrole (Py) and halloysite (H) mixtures with different ratios were polymerized in aqueous medium with the in situ technique using ammonium persulfate (APS) as a radical initiator. Halloysite, polypyrrole (PPy) and the prepared composites were examined by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), thermal analysis (TG/DTA) and nitrogen adsorption/desorption (N-2-AD) techniques. According to XRD analysis, the crystal structure of the halloysite was seen to be unchanged by the composite formation, but completely transformed to metahalloysite. The SEM and TEM images showed heterogeneous distribution of the halloysite in the polymer matrix with single bundle dispersions of the nanotubes. The results indicated that the flame retardant character of the composite increased whereas adsorption capacity, surface area and nanopore volume decreased with increasing PPy content. The conductivity behavior of composites was also studied.