Synthesis of Polypyrrole/V2O5 Composite Film on the Surface of Magnesium Using a Mild Vapor Phase Polymerization (VPP) Method for Corrosion Resistance

Yanan Sun,Xiuming Zhang,Dongtao Ge,Wei Shi,Jiawei Li,Yuan He

doi:10.3390/coatings10040402

Abstract

The vapor phase polymerization (VPP) method is a conventional strategy for synthesizing conducting polymers (CPs) on the surfaces of various materials. However, the current VPP method performed on a metal surface usually requires harsh reaction conditions, such as high temperature and low vacuum. In this paper, a polypyrrole (PPy) and vanadium pentoxide (V2O5) composite film was synthesized on the surface of Mg using a mild VPP method. Here, V2O5 was used as an oxidant, and it was found that the oxidation of pyrrole (Py) vapor on the surface of V2O5, which had been previously coated on the surface of Mg, could be performed at room temperature under normal atmospheric pressure. The formation of the PPy/V2O5 composite was verified by Fourier transform infrared spectroscopy (FTIR) and energy dispersive X-ray (EDX) spectroscopy. A thermogravimetric analyzer (TGA) was used to study the thermal stability of the composite. Subsequent corrosion tests showed that the PPy/V2O5 composite film could slow down the corrosion of Mg in 3.5 wt% NaCl. It is expected that the mild VPP method may find great potential in the fields of synthesis of CPs and the corrosion protection of reactive metals.

Highlights

Metals are of industrial interest as structural material due to their high density and high strength to weight ratio
All the above steps are into PPy, thereby obtaining a PPy/V2O5 composite film on the Mg surface
A mild vapor phase polymerization (VPP) method has been successfully developed for the synthesis of a PPy/V2 O5 composite film on the reactive metal Mg

Summary

Introduction

Metals are of industrial interest as structural material due to their high density and high strength to weight ratio. Their poor corrosion resistance limits their applications. In the last two decades, with the development of metal chemistry, alloying effects, and the electrochemical and polymer field, research has produced many options for the improvement of the corrosion resistance of metals, such as electrochemistry [1,2], chemical coatings [3], electroplating [4], and chemical oxidation anticorrosion [5]. Anticorrosive coatings include organic polymers [6], metal oxide [7], and graphene-containing composites [8]. Among them, conducting polymers (CPs) are one of the most important coating materials due to their electronic conductivity, optical transparency, and mechanical flexibility [9,10,11,12]

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Conclusion