【摘要】：本文利用防己和延胡索兩種富含生物堿的中草藥作為提取緩蝕劑的原料,使用有機溶劑回流提取法制備得到實驗所用緩蝕劑。采用傅里葉變換紅外光譜、電化學(xué)阻抗譜、動電位極化曲線、失重實驗、接觸角測試、紫外可見光譜、掃描電子顯微鏡、掃描電化學(xué)顯微鏡和能譜儀等研究了兩種提取物對J55鋼在3.5%NaCl飽和C02溶液中的腐蝕、吸附行為和添加緩蝕劑前后J55鋼表面腐蝕形貌。實驗結(jié)果顯示:防己和延胡索提取物對J55鋼的腐蝕都具有較好的抑制效果,當加入4%體積比的提取物緩蝕劑時,通過阻抗測試得到的緩蝕效率分別為92.14%和87.15%;兩種緩蝕劑都屬于以抑制陽極反應(yīng)為主的混合型緩蝕劑,二者在J55鋼表面上的吸附行為均符合Langmuir等溫吸附模型;防己和延胡索緩蝕劑在金屬表面吸附是一個在熱力學(xué)上自發(fā)、放熱的過程。防己和延胡索提取物中都含有C=O、N-H、O-H、C-O、C-N、苯環(huán)等具有緩蝕作用的極性基團,含有這些基團的有機物分子能夠在J55鋼表面吸附形成一層具有保護作用的有機物分子保護膜,減輕腐蝕介質(zhì)對J55鋼的腐蝕。為了進一步探究和驗證防己和延胡索提取物中主要起的緩蝕作用的成分,本文通過文獻資料調(diào)研、極化曲線和紅外光譜等測試方法,確定了防己和延胡索提取物中主要起緩蝕劑作用的組分分別為粉防己堿和延胡索乙素。隨后使用第三章中相同的研究手段,對粉防己堿和延胡索乙素的緩蝕效果進行了詳細的研究。電化學(xué)實驗結(jié)果顯示:在所研究的六種成分中粉防己堿和延胡索乙素對J55鋼具有最好的腐蝕抑制效果,當添加量同為400mg/L時,二者通過電化學(xué)阻抗譜計算得到的緩蝕率分別達到90.39%和90.46%,粉防己堿和延胡索乙素的吸附同樣遵循Langmuir等溫吸附式,屬于混合型緩蝕劑;接觸角、掃描電化學(xué)顯微鏡與掃描電子顯微鏡的結(jié)果均表明,粉防己堿和延胡索乙素在J55鋼表面吸附成膜。采用Gaussian軟件對粉防己堿和延胡索乙素分子的量化參數(shù)進行計算,結(jié)果顯示在氣相(真空)和液相環(huán)境下計算得到計算結(jié)果差別不大;兩種有機物分子的EHOMO比較接近,供電子能力大致相同;雖然延胡索乙素分子的ELuMo及△E均較小,但與粉防己堿差別不大,表明二者具有近似的腐蝕抑制效果,這與實驗的測試結(jié)果相吻合。采用分子動力學(xué)模擬方法研究了粉防己堿與延胡索乙素分子在Fe(110)面的吸附行為。計算結(jié)果顯示,二者都傾向于平行吸附在Fe(110)表面,并且延胡索乙素的吸附能略大于粉防己堿,這一結(jié)果與量子化學(xué)和實驗測試取得的結(jié)果一致。
[Abstract]:In this paper, two kinds of alkaloid-rich Chinese herbal medicine, Fangji and Corydalis, were used as raw materials to extract corrosion inhibitor, and the corrosion inhibitor was prepared by organic solvent reflux extraction method. The corrosion, adsorption behavior and surface corrosion morphology of J55 steel in 3.5%NaCl saturated CO2 solution were studied by Fourier transform infrared spectroscopy, electrochemical impedance spectroscopy, potentiodynamic polarization curve, weightlessness test, contact angle test, UV-vis spectrum, scanning electron microscope, scanning electrochemical microscope and energy dispersive spectroscopy. The experimental results show that both Fangji and Yanhusuo extract have good inhibition effect on the corrosion of J55 steel. When 4% volume ratio of extract inhibitor is added, the corrosion inhibition efficiency is 92.14% and 87.15%, respectively, and the two inhibitors belong to the mixed corrosion inhibitor which is mainly to inhibit the anodic reaction, and the adsorption behavior of the two inhibitors on the surface of J55 steel accords with Langmuir isotherm adsorption model, and the corrosion inhibition efficiency of the two inhibitors on the surface of J55 steel is 92.14% and 87.15%, respectively, and the adsorption behavior of the two inhibitors on the surface of J55 steel is in accordance with the corrosion isotherm model. The adsorption of corrosion inhibitors on metal surface is a thermodynamic spontaneous and exothermic process. Both the extract of Fangji and Elaeagnus angustifolia contain the polar groups such as C 鈮，

本文編號：2497677