Electrochemical degradation of Pellethane 2363-80A and 2363-55D

• Published in: Polymer degradation and stability 1992, Vol.37 (3), p.183-188
• Main Author: Dillon, J.G.
• Format: Article
• Language: English
• Subjects: Applied sciences; Chemical reactions and properties; Degradation; Exact sciences and technology; Organic polymers; Physicochemistry of polymers
• ISSN: 0141-3910; 1873-2321
• DOI: 10.1016/0141-3910(92)90158-2

The electrochemical degradation of two polyetherurethanes, Pellethane 2363-80A and 2363-55D was studied. Size-exclusion chromatography (SEC) and Fourier transform infrared spectrometry (FTIR) were used to monitor the chemical changes in thin films of the polymer coated on electrode surfaces. These films were exposed to a 6 V DC for a period up to 177 days. Evidence for extensive aggregation was noted during preliminary SEC measurements in dimethylacetamide (DMAC), whereas measurements in DMAC/0·5 m-LiBr eliminated the aggregation. The peak molecular weight of the polymer film on the reduction cathode decreased from 107 000 to 105 000 (−2%), whereas the molecular weight of the film at the oxidation anode was 31 000, a decrease of 71%. Periodic FTIR analysis of the films indicated alteration in the NH stretching, carbonyl, and COC portion of the polymer chain with time. The alterations were similar for both 80A and 55D, although taking longer to appear with 55D. The infrared difference was electrode-specific with little change occurring at the cathode and major change at the anode. Evidence for the production of free amine or alcohol was also present in the infrared spectra, with areas of yellowing appearing on the electrode surfaces. A non-adhering residue was produced on the surface of the anode film. All controls (air, glass, Pt, thermal, H 2O, and 0·9% NaCl) showed no differences in infrared absorbances.