Research On The Pipeline Internal Corrosion Protection Of Nano Epoxy Coatings

Epoxide resin is commonly coating that used in pipeline anti-corrosion.It possesses many features such as upstanding mechanical property,high binding force,low shrinkage,well stability,excellent dielectric protecties and so on.However, its usage is restricted by some shortcomings like brittle,low fatigue durability,low heat resisting property,low impact toughness when it solidified.We try to mix some modified nano TiO₂ into traditional coating,we choose coupling agent KH550 to modify nano TiO₂ by contrast test in order to change the balance of hydrophilic-lipophilic; Analyze the influence of some facters on degree of oil-affinity and the water-sorption rate such as volume and concentration of coupling agent,Duration and temperature of modification and PH value;Confirm optimum technology of coupling agent by Yunifomuekusuperimento:PH value is 8,0.3ml of KH550 per every gram of nano TiO₂, concentration of coupling agent is 0.05mol/L,duration of modification is 90 min,temperature is 50℃.Ascertain the quantity of nano TiO₂ that added into coating is 2% by settlement test, then put 2% modified nano TiO₂ into epoxide resin under the circumstances of mechanical rabbling and sonic oscillation in 1h, Detect the performance of Nano epoxy coatings according to national standards, the storability, abrasive resistance,viscosity, degree of fineness of Nano epoxy coatings improved a lot compared with common coating. Observe the surface toppgraphy of coating by SEM and EDS,nano TiO₂ fill the aperture and cavities and this crosslinked structure make the combination of coating more tight.Investigate corrosion–resistance of Nano epoxy coatings and common coating by fog cabinet,EIS,what we can see from the test: the weight gain in common coating is much larger than in Nano epoxy coatings,this is because the nano-particle padded the gaps between epoxy molecules,made the combination of molecules more tight,prevented the percolation of water and ion, improve corrosion-resistance of coating by the restraint of the electrochemical corrosion. The polarization resistance Rp of electrode face in EIS test increased, capacitance C decreased ,this is because the interfacial interaction between nano TiO₂ and coating improve the packed density of coating,lessen the microdefect corrosion, so the impedance of coating raised.