The use of conducting polymers as coating layers for the protection of surfaces against corrosion represents an important topic for investigation, as reported in the literature. In this work, polypyrrole/Fe3O4 nanoparticles (Fe3O4_NPs/PPy) hybrid nanocomposites (HN) were incorporated as anticorrosive additives in an epoxy paint to protect SAE 1010 carbon steel from corrosion. The HN particles were obtained by chemical polymerization of pyrrole in an aqueous solution in the presence of Fe3O4_NPs and were characterized by infrared absorption spectrophotometry, dynamic light scattering (DLS), X-ray diffraction (XRD), transmission electron microscopy (TEM). The electrochemical impedance spectroscopy (EIS) was used in the analysis of the electrochemical response of the coated surface with and without HN. DLS data showed that the Fe3O4_NPs and Fe3O4_NPs/PPy obtained in solution present average diameters of (19.7 ± 9.6) nm and (63.5 ± 27.7) nm, respectively. TEM images showed Fe3O4_NPs with smaller sizes (10 nm - 30 nm), and that the HN had diameters smaller than 100 nm, consisting of Fe3O4 cores coated with polypyrrole. EIS measurements have shown that the addition of HN to the epoxy paint could improve the efficiency of the anticorrosive coating when compared to the original epoxy paint prepared without any corrosion inhibitor.

We discuss the preparation of Polypyrrole and Polylactic Polyacid (PPy/PLA) based blends and the subsequent investigation of their antibacterial properties. After being molded through injection processing, the blends were characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), Impedance Spectroscopy (IS), contact angle, thermogravimetry (TGA), and dynamic mechanical analysis (DMA). FTIR analysis confirmed the presence of PPy chains and the IS results indicated that the blends prepared with a 50% mass fraction of PPy have a conductive character. While the SEM images reveal the presence of small cracks on the surface of the samples, DMA analyses show that a decrease in their mechanical strength occurs in the 50°C-60°C range, with the blend with a 50% PPy load exhibiting the greater resistance and being able to withstand temperatures of the order of 120°C. The TGA degradation profile varies according to the amount of polypyrrole present in the blends, with those containing 50% PPy being able to retain about 32% of the polypyrrole mass at 600°C. The antibacterial activity tests done with the injected blends reveal that while no inhibition halo was formed for the Escherichia coli bacterium, the growth of Staphylococcus aureus is inhibited in the 50% PPy blend.

The production of conductive and organic devices from a 3D printer represents a promising strategy for several areas. In particular, the synthesis of polypyrrole-coated acrylonitrile butadiene styrene (ABS) composites can be considered an important step to produce conductive supports for 3D printing. Herein, it is reported the production of ABS samples through the additive manufacturing process (3D printing) accordingly to the Fused Deposition Modeling (FDM) method. The hydrophilic behavior was controlled by the surface treatment using air plasma for the following step of coating with polypyrrole (PPy) via an in situ polymerization, using two different oxidants: ferric chloride (FeCl3.6H2O) and ammonium persulfate (APS). The chemical, optical, surface, and electrical properties of these materials were characterized through Fourier Transform infrared spectroscopy (FTIR), contact angle measurements, cyclic voltammetry, Scanning Electron Microscopy (SEM), 4-probe electrical measurement, and mechanical tensile testing. The ABS/PPy (FeCl3) composite exhibited a low electrical contact resistance and better performance for applications that require electrodes with a good conductance level.