| Ice accretion can cause significant threats to power systems,polar ship,aviation and other fields.Therefore,efficient and economical ice-phobic coatings are crucial for production safety and the national economy.The application of silicone is widely used in icephobic materials because of its low surface energy and weatherability;Meanwhile,epoxy resin has excellent mechanical properties and adhesion properties,and which is the main material in coating field.As a consequence,in this thesis,silicone/epoxy resin system is used to prepare icephobic coating.Since silicone polymers and epoxy resin cannot be blended directly due to their poor compatibility,in this thesis,icephobic coatings were prepared base on binary copolymer and interpenetrating polymer network(IPN),and the systematic study of its icephobic performance and mechanism were carried out.First,with the amino terminated polydimethylsiloxane(Amino-silicone oil)copolymerization modified epoxy resin as matrix,by adding mixed-sized micro/nano silica particles,silica-filled dimethyl-silicone oil-modified epoxy coatings with different surface morphology were prepared.The contact angle(CA)and ice adhesion strength of coatings were measured(-10?).The surface chemical state and surface morphology of the coating were characterized by X-ray photoelectron spectroscopy(XPS),scanning electron microscope(SEM)and white-light interferometer.The results show that,the CA of dimethyl-silicone oil modified epoxy was increased from ?68° to ?106°.The CA of the sicilia-filled coatings with an appropriate weight ratio of micro/nano silica particles could achieve be increased to more than150°,but its ice adhesion strength was much higher than that of the smooth coating with the same chemical properties due to mechanical interlock.Based on the epoxy/PDMS IPN matrix,by adding dimethyl-silicone oil to adjust the elastic modulus,the epoxy/PDMS IPN gel coating was prepared.The effects of elastic modulus on ice adhesion strength(-10?)were studied.The results show that the elastic modulus of the coating was significantly reduced by dimethyl-silicone oil(< 0.2 MPa),and the ice adhesion strength of the coating is less than 10 k Pa.Coating adhesion and icing/de-icing cycle test showed that the substrate adhesion and durability of epoxy/PDMS IPN gel coating were much higher than that of pure PDMS gel coating.The IPN gel coating also has a low ice adhesion strength(< 20 k Pa)at-30?,which shows good low temperature resistance of the coating.Finally,the effects of mechanical properties of coating on the critical separation force and debonding mode of ice-elastic coating were studied by theoretical method and finite element(FE)numerical simulation.The analytical solution of the debonding of a rigid cuboid(denote ice block)with a square bottom from a finite thickness elastic layer(denote coating)under normal load is derived by using the Griffith energy balance principle.Then the critical separation force and debonding behavior of an ice block under normal and tangential load are studied by using cohesive zone model(CZM)in numerical simulation.The effects of elastic modulus,thickness and Poisson's ratio of the coating on the critical separation force and debonding behavior were analyzed.Researches showed that when the elastic modulus is small enough,the critical separation force of ice debonding increases monotonically with the elastic modulus,and the ice debonding mode is crack propagation mode.When the elastic modulus is large enough,the critical separation force is infinitely close to a certain value.In this case,the debonding mode is uniform separation mode. |
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