Polyester-epoxy resin/conducting polymer/barium sulfate hybrid composite as a smart eco-friendly anti-corrosive powder coating

Abstract This study presents new smart eco-friendly and environmentally acceptable conducting polymer composites. These composites represent high efficient anti-corrosive coatings based on (toluidines and phenylenediamines) /BaSO4 polymer composites for steel protection. These polymer composites were prepared by in-situ chemical oxidative polymerization of (ortho, meta or para) toluidines and phenylenediamines monomers each alone in the presence of BaSO4 extender pigment. The polymerization process was carried out using ammonium peroxydisulphate as an initiator at 0-5 °C. The prepared composites were characterized using spectrophotometric measurements (FTIR, XRD, EDX, SEM), in addition to thermal analysis (DSC & TGA). Small doses of these composites (not exceed 2%) were incorporated into powder coating formulations. The coating formulations including the (toluidines or phenylenediamines / BaSO4) polymer composites were evaluated as corrosion inhibitors. The coated steel panels were examined in a salt spray cabinet for 1500 h with a continuous follow up every 200-300 h. The coating formulations containing conducting polymer/BaSO4 composites achieved impressive and high performance effect in protecting steel panels from corrosion compared with the blank sample. Moreover, electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization results also confirmed the high performance corrosion protection properties of polyester/epoxy/conducting polymers/BaSO4 hybrid composites.