The synthesized composites were loaded in polyvinylbutyral (PVB) to develop coating for mild steel substrates. A comparative study of the corrosion protection efficiency of carbon steel coated with PVB and PVB containing composites was evaluated by measurement of open circuit potential (OCP), Tafel polarization and electrochemical impedance spectroscopy (EIS). | Vietnam Journal of Science and Technology 56 (3B) (2018) 104-116 THE ROLE OF COUNTER ANIONS IN ANTICORROSIVE PROPERTIES OF SILICA-POLYPYRROLE COMPOSITE Vu Thi Hai Van1, 2, Pham Thi Nam1, Nguyen Thi Thom1, Nguyen Thu Phuong1, Nguyen Thi Thu Trang1, To Thi Xuan Hang1, Dinh Thi Mai Thanh1, 3, * 1 Institute for Tropical Technology, VAST, 18 Hoang Quoc Viet, Cau Giay, Ha Noi 2 Graduate University of Science and Technology, VAST, 18 Hoang Quoc Viet, Cau Giay District, Ha Noi 3 University of Science and Technology of Hanoi, VAST, 18 Hoang Quoc Viet, Cau Giay District, Ha Noi * Email: dmthanh@ Received: 20 July 2018; Accepted for publication: 9 September 2018 ABSTRACT Silica/Polypyrrole (SiO2/PPy) composites were synthesized in the presence of different counter anions as oxalate (Ox), benzoate (Bz) and dodecyl sulfate (DoS). The morphology and properties of composites were characterized by FTIR, EDX, SEM, TGA and CV method through the two-point-electrode. The synthesized composites were loaded in polyvinylbutyral (PVB) to develop coating for mild steel substrates. A comparative study of the corrosion protection efficiency of carbon steel coated with PVB and PVB containing composites was evaluated by measurement of open circuit potential (OCP), Tafel polarization and electrochemical impedance spectroscopy (EIS). It was found that SiO2/PPyOx could provide much better protection, with the lowest current density (×10-8 and highest impedance modulus (×10-8 ) when compared with SiO2/PPyDoS and SiO2/PPyBz due to the small size and inhibitive ability of oxalate anion. Keywords: silica/polypyrrole, counter anions, corrosion protection, PVB coating. 1. INTRODUCTION The serious consequences of the corrosion process have become a global problem which cost US$ trillion per year, equivalent to roughly percent of the global Gross Domestic Product [1]. Generally, the common way to protect or reduce the corrosion rate is coating on the metals .
