General procedures to determine the composition of commercial, two-part polysulfide aircraft sealants
Article first published online: 10 MAR 2003
Copyright © 1990 John Wiley & Sons, Inc.
Journal of Applied Polymer Science
Volume 41, Issue 11-12, pages 2837–2856, 1990
How to Cite
Ennis, B. C., Hanhela, P. J., Huang, R. H. E., Long, G. J. and Paul, D. B. (1990), General procedures to determine the composition of commercial, two-part polysulfide aircraft sealants. J. Appl. Polym. Sci., 41: 2837–2856. doi: 10.1002/app.1990.070411126
- Issue published online: 10 MAR 2003
- Article first published online: 10 MAR 2003
- Manuscript Accepted: 16 FEB 1990
- Manuscript Received: 14 AUG 1989
Interpretation of the chemical processes which polysulfide sealants undergo either on storage or when the cured material is subjected to environmental influences requires detailed knowledge of formulations. Procedures have been developed to isolate and identify a range of additives in two-part commercial aircraft sealants of both the dichromate and manganese dioxide cure types. Solvents, curing agent dispersants, and cure rate modifiers were separated chemically and thermal analysis was demonstrated to provide a ready means to estimate carbon in fillers. The phenolic resin adhesion enhancers were conveniently determined using 13C-NMR spectroscopy and could also be identified using size exclusion chromatography. It was shown that virtually no interaction occurred between polysulfide liquid polymers and phenolic resins following aging at 70°C for 7 days. The most appropriate methods for determining curative levels were established and new means of assessing thiol content of the polysulfides by both 13C-NMR and PMR spectroscopy are described. The significance of aspects of the sealant formulations is discussed.