Study On Preparation And Properties Of Water Resistant Polyurea Insulation Coatings

Polyurea coating is a new environmental protection coating,which is widely used in the field of various material protection.Compared to other materials,polyurea has solvent-free,self-curing,excellent water resistance,chemical resistant property,high tensile strength,ageing-resistant performance and so on.However,the existing insulating coatings all have problems of poor water resistance and corrosion resistance,therefore,combining the polyurea waterproof coating with the existing insulation coating that can effectively improve the water resistance and insulating property of the entire insulation structure.This article takes diethyl maleate to modify amino-terminated polyether and chain extender,to get modified amino-terminated polyether and modified chain extender,putting HDI tripolymer as the A components of polyurea and modified amino-terminated polyether and chain extender as the R components of polyurea,to prepare different polyurea Coatings.The water resistance,breakdown field strength and mechanical property of polyurea coating were tested,and the impacts of the type and amount of chain extender and the modification of the chain extender and the compounding of different amino-terminated poly ether on the performance of the polyurea were discussed.The results show that:the use of diethyl maleate modified amino term-inated polyether and chain extender can reduce its reaction rate with isocy-anate and prolong its gel time.The result of the polyurea coating water resistance test shows that different amino terminated polyether and chain extender prepared polyurea coating has good water resistance.Through the test and analysis of the polyurea properties,it is found that the volume re-sistivity,shore hardness and tensile strength of the polyurea gradually incre-ase with the increase of the molar fraction of the chain extender,while the breakdown field strength first increases and then decreases,the elong-ation at break decreased gradually;compared with E100,polyurea with ext-ender E300 had higher volume resistivity,breakdown field strength,hardne-ss and tensile strength;The polyurea prepared by modifyed E300 has a re-latively lower curing speed,and the breakdown field strength is obviously improved,but the mechanical properties of the polyurea are decreased;an-d the same chain extender preparation of the polyurea coating to modified ED600 as amino terminated polyether,had higher insulation properties,tens-ile strength and hardness;different amino terminated polyether compound study found that improving the proportion of modified ED600 can effective improve the over-all performance of polyurea.