聚N-乙烯基咪唑对盐酸介质中Q235钢的缓蚀性能

Corrosion Inhibition of Poly N-vinyl Imidazole for Q235 Steel in HCl Solution

以N-乙烯基咪唑单体为原料,偶氮二异丁腈为引发剂,苯为溶剂,合成聚N-乙烯基咪唑(PVI)。采用静态失重法、Tafel极化曲线以及电化学阻抗法研究不同温度和含量下PVI在HCl溶液中对Q235钢的缓蚀性能,并研究了其缓蚀机理及缓蚀剂吸附方式。结果表明:在298K下,1 mol·L-1HCl溶液中,缓蚀剂浓度为2mg·L-1时,缓蚀效率达到90.1%,在高温(328 K),高酸(2 mol·L-1)下的缓蚀率仍可达到84%以上。电化学测试结果表明,PVI属于混合型缓蚀剂,与金属的吸附符合Langmuir吸附等温关系式;吸附自由能结果表明,缓蚀剂具有强烈的在金属上吸附的倾向,主要以化学吸附方式为主。

Poly N-vinylimidazole(PVI) was synthesized using N-vinyl imidazole as monomer and azodiisobutyronitrile(AIBN) as initiator in a solvent of benzene. Its corrosion inhibition for Q235 carbon steel in HCl solution were investigated by means of mass loss method, Tafel polarization measurement and electrochemical impedance spectroscopy(EIS). Results indicate that inhibition efficiency of PVI can reach 90.1% in 1mol·L-1 hydrochloride acid with 2mg·L-1PVI at 298K, and it can reach above 84% at high temperature(328K) in solution of high acidity(2mol·L-1). The electrochemical measurements suggest that PVI is a kind of mixed type inhibitor, the adsorption of PVI on the surface of metal obeys the Langmuir adsorption isotherm, free energies of adsorption calculated indicate that PVI exhibits strong tendency of adsorption on metal via chemical adsorption.