Improved antibacterial, antifouling and corrosion protective performance of epoxy coatings with poly(m-aminophenol)

Poly(m-aminophenol) (PmAP) was prepared by oxidation polymerization of m-aminophenol in alkaline medium and characterized by scanning electron microscopy (SEM), FT-IR spectra, UV-visible absorption spectra and X-ray photoelectron spectroscopy. The antibacterial behavior of PmAP was characterized by stepwise dilution method, and the results demonstrate that the PmAP displayed excellent antibacterial property against both Gram-negative Escherichia coli and Gram-positive Bacillus subtilis. Furthmore, epoxy coatings containing different amount of PmAP using cardanol-based phenalkamine as curing agent were prepared. The coatings containing PmAP exhibited higher antibacterial activity against Escherichia coli and Bacillus subtilis. In addition, the antifouling property of the coatings was investigated by immersing the films in bacterial suspension for four days. The results showed that the coatings containing PmAP possessed high ability to inhibit the formation of biofilm which is the key process to prevent the occurrence of biofouling in the initial stage. Meanwhile, the coatings with PmAP possessed high corrosion protective performance shown by immersion tests in 12% NaCl solution monitored by the electrochemical impedance spectroscopy (EIS). The experimental results might give some new insight into designing and application of multifunctional materials used in the preparation of coatings.