Premium
Investigation of the water and fuel exposure characteristics of aircraft fuel tank sealants and the effect on their glass transition temperature
Author(s) -
Giannis S.,
Adams R. D.,
Clark L. J.,
Taylor M. A.
Publication year - 2008
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.27961
Subject(s) - sealant , glass transition , absorption of water , materials science , plasticizer , composite material , desorption , absorption (acoustics) , chemistry , polymer , organic chemistry , adsorption
Abstract The water and fuel absorption and desorption characteristics have been studied of aircraft fuel tank sealants. The sealants were an epoxy‐cured polythioether and a MnO 2 ‐cured polysulphide. The effect of the water and fuel exposure on the glass transition temperature was also investigated. Water diffusion was found to be Fickian for the polythioether sealant and the equilibrium plateau level was found not to be dependent on the immersion temperature. On the other hand, the polysulphide sealant demonstrated a clear non‐Fickian water uptake characteristic, with large uptake levels, which were attributed to water droplet formation in the volume of the bulk sealant. The glass transition temperature of the polythioether sealant was not affected by the presence of water (∼ 4% by weight) while that of the polysulphide was increased by ∼ 8°C for a water uptake level of ∼ 50% by weight. Fuel absorption followed a very similar trend for both sealants with the weight gain demonstrated an early maximum followed by a subsequent weight decrease, indicating leaching of fuel soluble fractions, until equilibrium was reached. The presence of fuel acted as plasticizer for the sealants; depressing their glass transition temperature by ∼ 10°C. Tests on dried samples have shown that the effect on the glass transition temperature was reversible. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008