Study On Preparation And Performance Of Water-based Rust Inhibitor

The sustainable development of the society gives a higher request to eco-friendlytechnology and drives antirust to develop to the direction of environmentalfriendliness, multifunction, high-efficiency. Antirust protection technology is widelyused mechanical, chemical, energy, metallurgy and other sectors due to its lessconsumption, quick efficiency, low cost. According to the concept of greenenvironmental protection and different applications, different types of corrosioninhibitor were designed and prepared.The main contents and the results of this paper were as follows:(1)Firstly, the high purity of diethanolamine borate ester (DBE) was prepared.By reacting with Dodecanedioic acid dimethyl ester (DAM), a new type of organiccorrosion inhibitor which was Dodecanedioic acid diamide diethanolamine borateester (DAB) was synthesized. And the synthesis processes were explored andoptimized. Optimum reaction conditions for the synthesis of DBE were that molarratio of diethanol amine and boric acid was2.2, the amount of solvent was50mL andthe reaction time was8h. The product was colorless and sticky substance. Optimumreaction conditions for the synthesis of DAB were that molar ratio of DAM and DBEwas1.2/2, the reaction temperature was130℃and the reaction time was6h. Themass ratio0.4/0.6potassium hydroxide/sodium methoxide was used as catalyst. Thecompound alkali weight1%of the total weight of raw material. The product was lightyellow and sticky substance. The products were characterized by infrared spectra andnuclear magnetic resonance.(2)DBE and DAB that were already synthesized were used as water-basedantirust. The antirust performance of DBE and DAB was studied by anti-rusttreatment for large metal products. The results proved that the antirust capability ofDBE as corrosion inhibitor was worse and DAB had good antirust performance. Themonolithic stainless time of1%wt of DAB solution was more than48h. Under thesame experimental conditions, the laminated stainless time was more than8h.Theresearch of polarization curves showed that DBE did not have obvious effect onantirust. It was difficult for the DBE molecules to form strong chemical adsorptionfilm on metal surfaces. But DAB had excellent antirust performance. After adding different concentrations of DAB, the corrosion current density could be greatlyreduced by over two orders of magnitude. This indicated that DAB molecules formedsolid protective adsorption film. By comprehensive comparison of the two antirust, itwas found that the number of polar groups in the molecule had a certain influence onthe antirust performance, the more polar groups could form thicker film on the metalsurface by means of adsorption accumulation and show better antirust performance.(3)DAB which had better antirust performance was used in water-based cuttingfluid. By compounding with other additives and the orthogonal optimization, the bestcomposition of water-based cutting fluid was determined. According to nationalstandards, the physicochemical performance of the water-based cutting fluid wastested. The test result showed that the water-based cutting fluid had good antirustperformance and corrosion resistance.(4)For the temporary antirust of small metal pieces before coating process,inorganic antirust was often used. This paper developed a low-cost, betterperformance inorganic antirust which was zirconium antirust. The formulation wasoptimized via orthogonal test. The performance of as-prepared antirust was evaluatedbased on electrochemical corrosion test. The morphology and elemental compositionof the antirust film were investigated by means of scanning electron microscopy andenergy dispersive spectrometry. It was found that the optimum formulation ofas-developed rust inhibitor was0.5g/L zirconate,0.5g/L copper promoter,0.2g/Lcomplex agent and pH value of4. The corrosion current density of steel withprotection of antirust was dropped from0.0421mA·cm~-2to0.0084mA·cm~-2,thecorrosion potential was improved from-0.737V to-0.596V, the polarization resistancewas increased from367.6to2022.9,above all of these proved antirust film couldhave the effect of isolation and corrosion protection. Antirust film was adherent tosteel substrate evenly and mainly composed of the oxides of Fe and Zr. Becausezirconium oxide had wonderful corrosion resistance, zirconium antirust showedexcellent antirust effect.