Study On Chelation Reaction And Adhesion Of β-diketone With Iron

In this paper,fourβ-diketone molecules were synthesized.Their structures were characterized by FTIR and ¹H NMR.The reaction ofβ-diketone with iron under aerobic and anaerobic conditions was studied.The concentration of Fe³⁺was tested by ICP-OES,and the reaction mechanism ofβ-diketone and iron was explored.The experiment proved thatβ-diketone can only react with iron in the presence of oxygen.Iron is oxidized to Fe³⁺as an electron acceptor,and the oxygen atom in the carbonyl group of theβ-diketone molecule provided lone-pair electrons as an electron pair donor.The two interact to form a chelate.The corrosion of steel byβ-diketone was observed by SEM.It was found that theβ-diketone with the shortest alkyl chain at the side end had the fastest reaction rate with steel.Steel was the most seriously corroded.It proved that the shorter the alkyl chain at the side end,the higher the proportion of ketones.This is conducive to the formation of metal chelates.The contact angle test showed that the surface of the steel treated withβ-diketone was hydrophobic and the corrosion resistance was enhanced.In order to solve the problem that the reaction rate ofβ-diketone with iron is too slow at room temperature,electrochemical tests were used to accelerate the reaction ofβ-diketone with steel.In this paper,the effect of modified substrate surface on the bonding properties was first explored.β-diketone was used to treat steel at different time periods to obtain substrate surfaces with different roughness.The pits on the rough surface make more contact areas between the binder and the substrate,resulting in strong mechanical interlocking.It can improve the bonding strength of the bonding joint.After systematic experiments,the results showed that the bonding strength of the steel plate treated with propionylbenzoylmethane（MF-0/2）for 6 hours increased by 39.6%reaching the maximum value.Then the effect of modified acrylic adhesive on the bonding performance was explored.When the content of heptanoylbenzoylmethane（MF-0/6）reached 1wt%,the bonding strength was increased by36.6%compared with the original.However,the highest bonding strength of MF-0/6modified substrate surface was only increased by 27.0%.Because the modified steel surface only enhanced the mechanical interlocking between the binder and the substrate.by modifying the acrylic binder,not only the mechanical interlocking force between the binder and the substrate was enhanced,but also a new chemical bond was formed.the bonding performance is improved under the two forces.