一种新型联吡啶双子季铵盐的合成及缓蚀性能

Synthesis and Corrosion Inhibition Performance of a Novel Bipyridine Gemini Quaternary Ammonium Salt

以4,4'-联吡啶和氯化苄为原料,经季铵化反应制备了化合物1,1?-二苄基-4,4?-联吡啶双子季铵盐(PBA),产率为76.3%,通过FTIR、~1HNMR对产物结构进行了表征;利用失重法、电化学技术、AFM考察了PBA对1 mol/L盐酸溶液中Q235钢的缓蚀作用和其在Q235钢表面的吸附行为。结果表明,PBA是一种同时抑制阴、阳极的混合型缓蚀剂,缓蚀率随PBA浓度的增加而增加,随温度的升高而略有降低。当PBA质量浓度为80 mg/L时,缓蚀率可达96.53%。PBA在Q235钢表面的吸附为放热反应,遵循Langmuir等温式,是以化学吸附为主的混合型吸附。PBA在钢表面形成了一层致密的保护膜,大大阻碍了钢腐蚀。使用量子化学法研究了PBA的缓蚀机理,结果表明,PBA的活性区域集中于苯环和杂环上,且PBA分子接受电子的能力大于提供电子的能力。

1,1?-Dibenzyl-4,4?-bipyridine gemini quaternary ammonium salt(PBA)in 76.3%yield was synthesized by quaternization of 4,4-bipyridine.The structure of PBA was characterized by FTIR and^1HNMR.The corrosion inhibition of PBA on the Q235 carbon steel in 1 mol/L hydrochloric acid solution and its adsorption behavior on the surface of Q235 carbon steel were studied by means of weight loss method,electrochemical technique and atomic force microscope(AFM)observation.The results showed that PBA was a mixed inhibitor that inhibited both cathode and anode.The inhibition efficiency increased with the increase of PBA concentration and decreased slightly with the increase of temperature.When the mass concentration of PBA was 80 mg/L,the inhibition efficiency reached up to 96.53%.The adsorption of PBA on the surface of Q235 carbon steel was exothermic reaction,following the Langmuir adsorption isotherm,which was a mixed adsorption based on chemical adsorption.PBA formed a compact protective film on the steel surface,which greatly hindered the steel corrosion.Quantum chemical method was used to study the inhibition mechanism of PBA.It was found that the active region of PBA was concentrated on benzene ring and heterocyclic ring,and the ability of PBA molecule to accept electrons was greater than that to provide electrons.