Preparation And Properties Of Epoxy-based Basalt Fiber Reinforced Composite Coating

Basalt fiber is a new kind of environment-friendly fiber material,which is composed of silica,alumina,calcium oxide,magnesium oxide,iron oxide and titanium dioxide.It has high strength to weight ratio,good sound insulation,low water absorption and exceptional resistance to corrosion and heat,which is very popular and widely used in development of new material at present because of its natural environmental advantages.In this paper,three kinds of composite coatings were prepared using basalt fiber as the main filler,and the morphology and composition of fiber,composite coating and self-healing microcapsules were characterized by scanning electron microscope,energy dispersive spectrometer,X-ray diffraction,Fourier transform infrared spectrometer,X-ray photoelectron spectroscopy,thermogravimetric analyzer and other characterization methods;the adhesion of coating was evaluated by AT-M drawing instrument;the contact angle test,friction and wear test were used to demonstrated the stability and wear resistance of the coating respectively;corrosion resistance was studied by electrochemical workstation.The main contents of this paper are concluded as follows:(1)The basalt fiber reinforced epoxy composite coating was prepared,and the effect of fiber content on the protection of carbon steel surface by epoxy resin(E51)composite coating was studied.Due to the shielding effect of basalt fiber,the coating can isolate water and various ions from the metal surface,and decelerated the permeation rate of water and various corrosive media into the coating through the filling in cracks and free volume of the coating.The results show that the corrosion resistance of the composite coating doped with 15%basalt fiber particles is superior at room temperature,and the value of low-frequency impedance|Z|exceeds 10¹⁰?·cm².The contact angle of the coating is about 60°and the friction coefficient is 0.104.It is found that the coating has better stability and wear resistance.(2)The poly-dopamine is in-situ growth on the surface of basalt fiber which treated by coupling agent KH570.The cross-linking reaction between modifier and resin can form a close connection within the coating and run through the network structure of the whole curing system,this kind of structure can improve the interface effect between basalt fiber and epoxy resin,thus enhancing the corrosion resistance of coating.The difference of corrosion resistance and stability between the pure epoxy coating,the composite coating doped with basalt fiber before modification and the composite coating doped with basalt fiber after modification was studied.The results show that the low-frequency impedance modulus value|Z|of the modified basalt fiber doped composite coating reach 10¹¹?·cm²,which has better corrosion resistance,the structure is compact,so the adhesive force to carbon steel substrate is1.05 MPa.(3)A kind of isophorone diisocyanate nanocapsules with self-healing property was synthesized.The microcapsules and basalt fiber particles were added to the epoxy resin successively to prepare the anticorrosive coating with self-healing property.The effect of temperature on the morphology of microcapsules was investigated.It was found that ice bath was the best reaction temperature.The influence of the ratio of basalt fiber to IPDI microcapsules on the adhesion of composite coating was explored.The results showed that when the ratio of basalt fiber to IPDI microcapsules was 5:1,the coating had good adhesion.During the scratch test,the low frequency impedance|Z|decreased from 10⁸?·cm² to 10⁷?·cm² and then increased,the phase angle increased from 8°to 90°,which proves that the coating possesses self repairing performance.