Enhanced Corrosion Protection of Iron by Poly(3-hexylthiophene)/Poly(styrene-co-hydroxystyrene) Blends

Abstract

Corrosion of iron in NaCl solution is significantly reduced by poly(3-hexylthiophene) (P3HT)/poly(styrene-co-hydroxystyrene)(PS-co-PHS) blended coating layers, especially at elevated temperature. The interaction between sulfur (in P3HT) and hydroxyl group (in PS-co-PHS) leads to enhanced miscibility between P3HT and PS-co-PHS and results in improved thermal stability upon thermal treatment. Adhesion force between iron and the coating layer is increased with increasing hydroxystyrene ratio as revealing by the adhesion test (ASTM 3359). Anticorrosion properties from electrochemical experiments indicate great improvement over the P3HT/PS blend. Protection efficiency (PE) of P3HT/PS-co-PHS blend on iron increases and corrosion rate (mils per year, MPY) decreases upon thermal treatment, making P3HT/PS-co-PHS blend an excellent corrosion inhibitor and adhesion promoter material to the iron, especially with good thermal stability.