Abstract: | A sulfur‐quinone diol monomer, 2,5‐bis‐(2‐hydroxyethylthio)‐1,4‐benzoquinone (SQM‐2), was prepared by the reaction of 2‐mercaptoethanol with benzoquinone. SQM‐2 and polycaprolactone diol (number‐average molecular weight = 1250) were condensed with toluene diisocyanate to give sulfur‐quinone polyurethanes. Two compositions were prepared, SQPU‐1 containing 7 mol % SQM‐2 and SQPU‐2 containing 35 mol % SQM‐2. These thermoplastic polyurethanes were soluble in solvents used in magnetic tape coating processes. The polymers were used to prepare magnetic coatings containing state‐of‐the‐art commercial iron particles. The sulfur‐quinone polyurethanes protected the iron particles against corrosion from a pH 2.0 aqueous buffer. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3278–3283, 2000 |