Corrosion resistance of epoxy composite coatings for the transport industry in aggressive environments

Epoxy diane oligomer ED-20, 2,4-diaminoazobenzene-4'-carboxylic acid modifier, polyethylene polyamine hardener,microdispersed particles of synthesized powder charge and a mixture of discrete fibers were used to form composite materials and protective coatings for the transport industry. The influence of aggressive media: oil, gasoline, sea water, acetone, NaOH (50 %), HCl (10 %) and H2SO4 (10 %) on the corrosion resistance of the developed composite materials with different content of ingredients was studied. The results of experimental studies suggest that the least swelling was observed for samples of composite containing components in the following ratio – modified binder: microdisperse filler in the form of a synthesized powder charge (Fe (70 %) + Ti (10 %) + TiC ) + Fe3C (5 %)) (d = 10–12 mm) : mixture of discrete fibers (modal (42 %), polyacrylic (38 %), polyamide (38 %)) – 100 : 0.05 : 0.10. The use of such a composite in the form of protective coatings of vehicles will ensure (if compared to the modified epoxy matrix) reduction of the permeability of aggressive media in: 1.5–1.7 times (when being used in oil and gasoline); 1.6–1.8 times (when being used in seawater, acetone and NaOH solution (50 %)); 3.0 and 2.5 times (when being used in solutions (10 %) of hydrochloric and sulfuric acids, respectively. Increased corrosion resistance compared to the matrix is caused by a decrease of the amount of polymer in the developed material and its increased cohesion strength, which increases the path of penetration of molecules of corrosive agents during their diffusion into the composite due to additives.