Spectroscopic, physical and product studies of the thermal degradation of poly(ethylene glycol) containing a 1,3-disubstituted phenolic group
UNSPECIFIED (1999) Spectroscopic, physical and product studies of the thermal degradation of poly(ethylene glycol) containing a 1,3-disubstituted phenolic group. POLYMER DEGRADATION AND STABILITY, 64 (2). pp. 329-338. ISSN 0141-3910Full text not available from this repository.
The high-temperature heat-exchanging oil Lutron KS1, a poly(ethylene glycol) containing a single benzene ring in the chain with 1,3-substitution, has been characterised by H-1 and C-13 NMR spectroscopy, IR, matrix-assisted laser desorption ionisation time-of-flight (MALDI-TOF) mass spectrometry and size exclusion chromatography (SEC); the latter shows it to have a low PDI (1.06) while H-1 NMR and MALDI-TOF indicate a peak molecular mass of 816 and 682 respectively. The 20-fold rise in viscosity of Lutron during industrial use at 170-210 degrees C over prolonged periods is shown to be due to the effect of oxygen in causing degradation to give carbonisation and the release of a range of volatile degradation products including CH3CHO, H2O, and di- and tri(ethylene glycols). Thermal degradation under N-2 gives a much more complex array of volatiles, including 18-crown-6; the formation of most of these involves simple homolysis followed by disproportionation. The SEC chromatograms of residual Lutron were bimodal, indicating extensive formation of high mass products. The 1% addition of various well-known antioxidants had only, at best, a marginal effect on reducing the oxygen-induced degradation; the most effective method of extending the service life of Lutron is to exclude oxygen during the heating process. (C) 1999 Elsevier Science Ltd. All rights reserved.
|Item Type:||Journal Article|
|Subjects:||Q Science > QD Chemistry|
|Journal or Publication Title:||POLYMER DEGRADATION AND STABILITY|
|Publisher:||ELSEVIER SCI LTD|
|Number of Pages:||10|
|Page Range:||pp. 329-338|
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