Preparation, Characterization And Anticorrosive Properties Of Intercalation Montmorillonite/poly(2,3-dimethylaniline) Composite

Recently, Polyaniline(PANI) has become a good candidate in anticorrosion coatingto replace chromium-containing materials, which have adverse effect on health andenvironment. However, PANI has always been considered as an intractable materialbecause of its poor solubility in most organic solvents, with a result of limiting itsfurther practical application.2,3-dimethylaniline(2,3-DMA) as an aniline derivative, hastwo electron-donating methylic substituent in the benzene ring. Many researchesindicated that electron-donating groups can lead to a larger steric volume amongmolecular chains, which can contribute to the increase of solubility and corrosionperformance.Montmorillonite as a layered material, whose lattice is composed of anedge-shared octahedral alumina sheet sandwiched between two tetrahedral silica sheets,and the lamellar elements of montmorillonite such as aluminum flakes can beintroduced into the polymeric coating to effectively increase the length of the diffusionpathways for oxygen and water as well as decrease the permeability of the coating. So,it is necessary to combine the advantages of these polymers and montmorillonite toobtain better corrosion protection for common metals.In this article, the intercalation MMT/P(2,3-DMA) composite was prepared byemulsion polymerization. The effects of MMT content, the concentration of APS andSDBS, the reaction time, the reaction temperature on the tafel curve, EIS curves andyield of PDMA composite are discussed; The as-prepared materials were characterizedby XRD, FT-IR and SEM, and the anticorrosive performance of the coatings containingP(2,3-DMA)/Epoxy(P(2,3-DMA)/EP) and PDMA/Epoxy(PDMA/EP) on iron sampleswas evaluated by electrochemical measurements in5wt%NaCl solution.The results showed that the composite of MMT clay with P(2,3-DMA) weresynthesized by emulsion polymerization. The PDMA with the best properties when theMMT content is5%, the radio of APS to2,3-DMA is2.5:1, the radio of DBSA to2,3-DMA is0.8:1, the reaction time is9h and the reaction temperature is30℃. The FT-IRspectra confirms the incorporation of MMT clay in P(2,3-DMA) matrix using emulsionpolymerization. The XRD and SEM results proved that P(2,3-DMA) chains have beeninserted in the clay layers and an intercalated P(2,3-DMA)/MMT composite has beensynthesized. The anticorrosive performance of PDMA/EP coating on steel was foundedto be better than pure EP coating in a long-time immersions time(288h), which went to show that the corrosion inhibition of P(2,3-DMA) could be effectively enhanced byincorporating MMT into the P(2,3-DMA) matrix.