Performance And Complex Research Of Imidazoline Pickling Inhibitor

Imidazoline corrosion inhibitor is a very popular research topic nowadays. These inhibitors have many advantages such as little pollution, little dosage, strong effect and low price. Imidazoline has been used as corrosion inhibitor for about70years.Imidazoline corrosion inhibitor has many uses. According to corrosive medium, imidazoline corrosion inhibitors are always used in acid medium, sometimes used in neutral medium or alkaline medium. According to useing scene, imidazoline corrosion inhibitors are always used in oil field, well drilling, pipeline, boiler, steel pickling and so on.For synthesizing imidazoline corrosion inhibitors, organic acid, diethylenetriamine, triethylenetetramine and Polyethylene polyamine are used to do condensation reaction in organic solvents. Then the product should be dehydrated. Common methods are vacuum method or solvent method.Chapter2introduces instruments, drugs and experimental methods. Weight loss method and introduce some other methods are mainly used. Weight loss method condition is steel material A3, corrosive media1M HCl, water bath temperature60℃and corrosion time4h. Inhibitor dosage is normally below3‰.Chapter3selects2-phenyl-2-imidazoline as main corrosion inhibitors, because this substance is a kind of standard imidazoline and don’t have long chain, thus its structure simple. Inhibition efficiency of singly using2-phenyl-2-imidazoline, thiourea and hexamethylenetetramine is determined. Inhibition efficiencies of them are60.3%,66.3%,84.8%.Then determine compounding effect of2-phenyl-2-imidazoline plus thiourea and2-phenyl-2-imidazoline plus hexamethylenetetramine. This proves that thiourea or hexamethylenetetramine can increase inhibition efficiency of2-phenyl-2-imidazoline. The last of Chapter3designs an orthogonal experiment of2-phenyl-2-imidazoline plus thiourea plus hexamethylenetetramine, using3level4factors template. So, these3drugs using together has a bad effect. Chapter4studies a series of self-made oleic acid imidazoline. Over20kinds of oleic acid imidazoline are made and4kinds are picked out. Their cyclization rates are10%,70%,70%,90%. Their exterior has apparent character, especially in winter, some of them stratified. Number1, number2, number3and number4are singly determined and number3is picked out according to inhibition efficiency and synthesis difficulty. When add1%∞number3oleic acid imidazoline, inhibition efficiency can reach98.0%.Then number3oleic acid imidazoline is used as main drug and successively compound with thiourea, hexamethylenetetramine, KI, propynol. Only propynol can increase inhibition efficiency of number3oleic acid imidazoline.In conclusion, in the condition of corrosive media1M HC1, water bath temperature60℃, corrosion time4h,1%∞number3oleic acid imidazoline plus1.2%∞propynol can reach inhibition efficiency of99.0%.