Amine-quinone polymers and the protection of iron particles against corrosion

A series of three amine-quinone monomers, containing the 2,5-diamino-1,4-benzoquinone functional group, were prepared by condensation of a secondary amino alcohol with hydroquinone. The amino substituent, R, was methyl (AQM-1), ethyl (AQM-20) or propyl (AQM-21). The monomers condensed with terathane 650 and TDI to give a series of polyurethanes. These polymers had a high affinity for the surface of commercial iron particles used in the state of the art magnetic tape and prevented the corrosion of the particles. Electrochemical impedance spectroscopy for films on iron squares showed that the adhesive bond between the amine-quinone polymer and the iron surface could not be broken by water. The nature of the bonding between the amine-quinone polymer and iron surface was proved by x-ray photoelectron spectroscopy and reflectance infrared spectroscopy.