浙江海洋大学外文翻译.docx

1、浙江海洋大学外文翻译浙江海洋大学毕业论文（设计）外文翻译学 院：石化与能源工程学院专 业：安全工程班 级：A13安工学 号：*二 年 月Advanced Materials Research Vol. 710 (2013) pp 41-44 Online available since 2013/Jun/27 at (2013) Trans Tech Publications,Switzerland doi:10.4028/Corrosion Inhibition of Chloroacetic-Acid Modified Imidazoline for Q235 Steel in H2SO4

2、 SolutionZhao Bin1,2,3,a Zou Like2,3,b(1. College of Materials and Chemical Engineering,Sichuan University of Science &Engineering,China；2.Material Corrosion and Protection Key Laboratory of Sichuan Province, China；3.Institute of Functional Materials, Sichuan University of Science & Engineering, Chi

3、na)a*.cn, b *.cnKeywords: quaternized imidazoline; corrosion inhibitors; weight loss measurement; polarization curveAbstract. A new chloroacetic-acid modified imidazoline (CAMI) was synthesized via the quaternization of imidazoline intermediate, obtained from the amidation and cyclization reactions

4、of benzoic acid and diethylene triamine, with chloroacetic-acid. The performance of the synthesized compound CAMI as corrosion inhibitor for Q235 carbon steel in 5% sulfuric acid solution was investigated by weight loss measurement and potentiodynamic polarization technique. The results show that CA

5、MI possesses strong inhibitive effect on the corrosion of Q235 carbon steel in acid medium and restrains the corrosion without changing the cathodic and anodic corrosion mechanism as a mixed-type inhibitor.Introduction Every year, heavy losses are caused by corrosion of metals in natural environment

6、, industrial production, oil and gas exploration and production. The application of corrosion inhibitors is one of the most effective and practical methods for protection metal against corrosion in various kinds of corrosion medium, especially in acidic media for that acid solutions are widely used

7、in industry, such as acid pickling, industrial acid cleaning, acid descaling and oil-well cleaning. The majority of well-known inhibitors are organic compounds containing nitrogen, sulfur and/or oxygen atoms 1-3. Among the various organic inhibitors used for inhibiting the corrosion of metal in acid

8、 medium, nitrogen-based organic inhibitors, imidazoline derivatives attract much attention duing to their excellent inhibition performance 4.However, most of the imidazoline derivatives are insoluble in water and need to be modified to improve their water solubility and corrosion inhibition performa

9、nce. In this work, a new chloroacetic-acid modified imidazoline (CAMI) was synthesized and its effectiveness and electrochemical behavior on the corrosion of Q235 steel was studied by weight loss measurement, potentiodynamic polarization technique.Experimental work Reagents and apparatus. All reagen

10、ts were available commercially and used as received without further purification. Q235 steel was used in electrochemical and weight loss studies. Test solutions were prepared by using AR grade sulfuric acid and twice deionized water. Aqueous solution of 5% sulfuric acid(mass ratio) was used as the c

11、orrosive medium.Infrared data was recorded as KBr discs on a Niclet 6700 FT-IR spectrophotometer. Electrochemical measurements were carried out on Electrochemical synthesis test system LK98C (Tianjin LanLiKe Chemical Electronic Technology Co., China).Preparation of imidazoline intermediate. Catalyst

12、 aluminum oxide and water-carrying agent xylene were added to the mixture of benzoic acid and diethylene triamine (1:1.2 mole ratio). The reaction mixture was stirred under nitrogen protection and heated to 140 and kept at thisAll rights reserved. No part of contents of this paper may be reproduced

13、or transmitted in any form or by any means without the written permission of TTP, . (ID: 128.122.253.228, University of New South Wales, Sydney, Australia-13/05/14,06:05:38)temperature for 3 hours, then gradually heated up to 200 and held at this temperature until there was no water being carried ou

14、t by xylene. The light-yellow solid of imidazoline intermediate was obtained while the xylene, residual benzoic acid and diethylene triamine were completely removed by vacuum distillation.OCOOHC-NHCH2CH2NHCH2CH2NH2+ 2NH2CH2CH2NHCH2CH2NH2Amidation140C, -2H2ONNCyclizationNClCH2COOH+200C, -2H2O60C, Qua

15、ternizationNCl-CH2CH2NH2H2NH2CH2CCH2COOHScheme 1. Preparation of imidazoline intermediate and CAMIPreparation of imidazoline corrosion inhibitor(CAMI).The mixture of obtained imidazoline intermediates and chloroacetic acid (1:1.3 mole ratio) was stirred at 60 for 3 hours to give the quaternized imid

16、azoline inhibitor (CAMI).Static weight loss test. The weight loss tests were performed on the metallic samples of Q235 steel sheet with dimensions of 2.0 cm 1.5 cm 0.2 cm, which were wet abraded with silicon carbide paper from number 200 to 2000 grit, washed with deionized water and degreased with h

17、exane and rinsed in isopropanol and acetone. For each test, three cleaned and dried samples were immersed in 5% H2SO4 (mass ratio) solution with setting concentration of inhibitor CAMI at setting temperature for 72h. The metallic samples were then removed from the aqueous solution, rinsed thoroughly

18、 with distilled water, ethanol and acetone, dried and weighted accurately again.The inhibition efficiency (, weight loss measurements) was determined according to Eq. 1:(%) = W0 W1 100% (Eq. 1)W0where W0 and W1 are the weight loss values in absence and presence of CAMI, respectively. Electrochemical

19、 test. Electrochemical studies (potentiodynamic polarization) were carried outby using a conventional three-electrode cell consisting of a Q235 steel working electrode, a saturated calomel electrode (SCE) as reference and a platinum auxiliary-electrode. The potentiodynamic polarization curves were o

20、btained by changing the electrode potential automatically from-200 mV to +200mV with a scan rate of 0.5 mV/s to study the electrochemical behavior of CAMI on the corrosion of Q235 steel. The inhibition efficiency (, electrochemical measurements) was determined according to Eq. 2:(%) = I0 I1 100% (Eq

21、. 2)I0where I0 and I1 are the corrosion current densities in absence and presence of CAMI, respectivelyResults and discussionsInfrared spectroscopy. The characteristic stretching frequencies for v(C=N in imidazoline ring) and v(NH in NH2) are peaked at 1651 cm -1 and 3277 cm-1, respectively. The max

22、ima NH bending (scissoring) vibration absorption in primary amine group is located at 1595 cm-1. The stretching vibrations peaks were seen at 3058 cm-1 for aromatic CH, at 3931 and 2862 for CH2, at 1074 and 1025 cm-1 for CN. The mono substituted aromatic ring on the imidazoline ring is indicated by

23、the absorptions at 703 and 774 cm-1. These infrared absorptions illustrate the formation of imidazoline intermediate.Gravimetric study. Fig.1 and Fig.2 show the variation of in 5% H2SO4 calculated from weight loss of the metallic samples, subjected to different inhibitor concentrations at constant t

24、emperature (25 C) and different immersion temperatures with the same CAMI concentration (30mg L-1), respectively.(%)90efficiency8580inhibition75706560102030405060Concentration of CAMI (mg/L)Fig. 1 The influence of CAMI concentrations on inhibitor efficiency As showed in Fig. 1, when the concentratio

25、n of CAMI is less than 30 mg L-1, increases quickly with an increasing in CAMI concentration, while a further increase causes no appreciable change in inhibition performance, which illustrates that the CAMI inhibitor molecules act by adsorption mechanism at Q235 steel/acid interface 5. The maximum i

26、s 88% when the CAMI concentration is 60 mgL-1.To assess the effect of temperature on corrosion inhibitive process, weight loss tests were performed in the temperature range 25-45 in 5% H2SO4 containing 30 mgL-1 CAMI inhibitor. The result shows that decreased sharply with increasing temperature (see

27、Fig. 2), which is consistent with the facts that corrosion rate in acid solutions increases exponentially with temperature increase because the hydrogen evolution overpotential decreases 2 and the reaction rate of imidazoline ring splitting increases with elevated temperatures 6.Electrochemical meas

28、urement. The effect of inhibitor concentration on both anodic and cathodic curves of carbon steel in 5% H2SO4 was studied using potentiodynamic polarization technique at different concentrations of CAMI inhibitor (0 and 300 mgL-1)，the obtained experimental results are shown in Fig. 3. As can be seen

29、 in Fig. 3, the slopes of the cathodic and anodic Tafel lines are not significantly influenced by the inhibitor concentration which suggests that the CAMI molecules restrains the corrosion of Q235 carbon steel without changing the cathodic and anodic corrosion mechanism 7. The presence of inhibitor CAMI (300 mgL-1) brings a significant effect on the currentpotential relations for both the cathodic and anodic process and the displacement in corrosion potential (30 mV) is much less than 85 mV. According to Ferreira et.al 8 and Li et.al. 9, when the displacement is more than 85