Preparation And Study On Spray Polyurea Coatings For Anti-corrosion Of Oil-pipeline

Spray Polyurea Coating is a new technology with a rapid development in recent 10 years in USA. Because of the excellent physical properties, the insensitivity to humidity and 100% solid content, it has been applied to many engineering projects. In this paper, the key component of Polyurea coating,Amine terminated Polyether(ATPE) was synthesized , the processing parameters of Polyurea coating was determined and the Polyurea coating used in the oil-pipeline was prepared.Firstly, Amine terminated Polyether was synthesized by three steps: the synthesis of Polypropylene glycol(PPG), the esterifying reaction of the PPG and the animating reaction of the esterifying product. The products of three steps were characterized by FT-IR , NMR and MALLS-GPC, respectively. Then factors which can determine the color and viscosity of ATPE and its conversion rate were also discussed.The polyurea spraying equipment was bought from Gusmer company. Using the spraying equipment, the processing procedures were determined by the spraying experiments. Specially, the processing parameters were identified that the spraying temperature is at 70-75℃, the spraying pressure is at 2000-3500psi and the difference between the A spraying pressure and the R spraying pressure should be at 500psi.The chemical and the formulating mechanisms of Polyurea coating were illustrated. The basic properties of Polyurea were investigated. Specially, the mechanisms of the Polyurea/Metal adhesion and the cathodic delaminating property of Polyurea coatings were discussed. Then, the effect of temperature, water and water transporting path on the adhesion and the cathodic delaminating property were investigated respectively. Finally, the Polyurea coating with good adhesion to metal and the good cathodic delaminating property was prepared.