| Basalt flakes is a new style of flake material,which is environmental-friendly and has low price. When basalt flakes pot into a resin, it will produce a special "labyrinth effect" in order to improve the corrosion resistance of coatings. So it has a Immense Potential in heavy anti-corrosion coatings field.Based on Russia's and China's basalt flakes and five kinds of curing agents being polyamide 651 A, the NX - 2015, T31, ethanediamine and triethylene tetramine, the influence of different types of basalt and different curing agents on the coating corrosion resistance has been researched. Firstly,the coating was prepared with the selected curing agent, and then the properties of coating corrosion resistance were researched with different quantities of basalt flakes. Secondly,with epoxy resin as modifier,the basalt flakes were modified with the method of high temperature ball milling. After the modification, the hydrophily of basalt flakes reduced, the lipophilicity enhanced and the basalt flakes in epoxy resin solution dispersion stability was greatly increased.In the end, the modified basalt flakes were added to the epoxy resin coating and the anticorrosion properties of the coating were studied.The results of the study are as following:(1) Different kinds of curing agent on the performance of the basalt flake coating is more evident. The most suitable curing agents among selected five kinds of curing agents are 651A and NX-2015. The surface coating performance is poor with the curing agent ethylenediamine and triethylene tetramine. And the surface coating performance with T31 is the worst.(2) The basalt flake preparation process has a large effect on the performance of the coating.In the process of coating preparation with ball mill dispersing, thin parts are easy to be broken because of uneven thickness. So the flakes are broken into powder without shielding effect. The EIS performance of coating and resistance to salt fog performance are poorer and the coating adhesion to metal substrate is low.(3) The thickness of flake anticorrosive coating has a larger influence on the corrosion resistance. When coating thickness is too thin, large size of the basalt flakes are easy to become corrosive medium channel and its corrosion resistance is even lower than the varnish coating. With the increase of coating thickness, blocking effect brought by the "maze effect"gradually play a leading role. The corrosion resistance of coating added basalt flake is better than varnish coating. And double coating thickness, the time of effective protection will increase a lot.(4) The optimum added amount of the basalt flakes in the coating has been found. The amount of curing agent NX-2015 coating and modified basalt 651A coating is about 20%. The amount of unmodified basalt 651A coating is about 15%.(5) The modification of basalt flakes surface can be realized by high temperature ball mill.The modification works best when the temperature is 140?, milling time of 5h and the speed of 800r/min. The corrosion resistance of coating modified by basalt increased significantly. The coating adhesion increased after modification. The photos of samples after 720 hours' salt spray test with cross fork showed a increase of salt spray resistance. |
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