| A series of amine-quinone polyurethanes (AQPU) derived from 2,5-bis(N-2-hydroxyethyl-N-methylamino)-1,4-benzoquinone (AQM-1) were synthesized and their physical properties were characterized. These polymers protected commercial iron particles from corrosion by pH 2 buffer better than the commercial binders used in magnetic tape. The amine-quinone functional group was confirmed to play a crucial role in the corrosion inhibition of the iron. The influence of different chemical structures of polymers on corrosion prevention was also discussed in this dissertation.;X-ray photoelectron spectroscopy (XPS) measurements showed that the N(1s) and O(1s) binding energies of 2,5-bis(N,N-dimethylamino)-1,4-benzoquinone (AQM-14A) on the iron shifted to higher values, illustrating that the amine-quinone functional group donated the electron density to the iron surface, which is indicative of a strong interfacial interaction. Reflectance absorption infrared spectroscopy (RAIRS) suggests that AQM-14A lies flat on the iron surface.;It was found that the addition of iron particles to AQPU binder impeded the mobility of AQPU molecular chain, hindering the crystallization process of AQPU. Isothermal TGA measurements under N2 purge revealed that there was less moisture in the AQPU binder protected magnetic iron coating than in other binders, proving that AQPU binder could replace the adsorbed water from the iron surface. The hydrophilic effect from different soft segments was also discussed in this dissertation.;2,5-Bis(N-hydroxyethyl-piperazyl)-1,4-benzoquinone (AQM-2) and a ring-chlorinated amine-quinone monomer (ClAQM) were prepared and showed a higher decomposition temperature (275°C). However, these polymers did not protect the iron particles against corrosion as well as the polymers containing AQM-1, although they were much better than the commercial binders.;At last a totally new class of polymers, sulfur-quinone polyurethanes (SQPU), was invented. The polymers gave a higher thermal stability (decomposition temperature >300°C and protected the iron from corrosion even a little better than AQPU Polymers. DSC, TGA, RAIRS, and XPS investigation pointed out that the sulfur-quinone functional group reacted with iron in a similar mechanism as the amine-quinone functional group did to iron. Electrochemical impedance spectroscopy (EIS) testing reported a strong interfacial reaction between the SQPU protecting film and the iron surface, demonstrating a better adhesion of SQPU onto the iron surface. |
