Study On Microstructure And Properties Of Fluorinated Polyurethane Elastic Coating The Corrosion

Water conservancy machinery is an important part of water conservancy project,also is an important support for the development of modern water conservancy conditions.In water conservancy machinery equipment,power is the core equipment of hydroelectric power generation.The turbine operates at high speed in the work,at the same time all kinds of hard particles such as liquid containing sediment,water environment under the debris contact.The leaves,base,shaft neck of turbine is easy to produce cavitation prone to erosion phenomenon.Once on the surface of the material resulting in cavitation,soon developed into a honeycomb pits,and thus the formation of abrasion,resulting in the turbine life relationship,and even cannot run,this is the normal operation of hydraulic power station caused serious influence.Therefore,how to solve the cavitation,abrasion and corrosion,improve the service life of water conservancy machinery,reduce use cost and maintenance cost,improve efficiency,is one of the turbines is safe,reliable and economic operation of the key issues.The polyurethane coating has opened up a new way of "Killing with Kindness" in the field of water conservancy machinery surface protection because of its excellent elasticity,abrasion resistance,flexibility,surface smoothness,high tensile strength and good coating coverage.But the polyurethane chain hydrophilic-CH₂OH group is easy to absorb water,resulting in a decline in the performance of polyurethane waterproof,in water environment seriously affect the polyurethane coating anti cavitation wear performance and service life.In order to solve the polyurethane elastic coating in water conservancy project in the long-term problem of water resistance under water environment,we generated hydrophobic fluorinated polyurethane?FPU?with fluorinated segments and non-hydrophilic-CH₂OH groups,by using the method of introducing fluorine with perfluoroalkyl ethanol?TEOH-10?for modification of two phenyl methane diisocyanate?MDI?and controlling the reaction process of MDI adding dosage and timing.Compared to hydrophilic unfluorinated polyurethane,this FPU has better water resistance adhesive force and anti-erosion performance.The water immersion test and the erosion wear experiment showed that when the molar ratio of TEOH-10 was 0.5 theoretical quantity of MDI,the water absorption of FPU was only 0.0146% and the cavitation erosion amount of FPU reduced from 2.3756×10-3kg to 0.9334¹.2454×10-3kg,which made the FPU can be used as a protective coating of under-water flow parts whose cavitation erosion is serious.