Application of ATR in characterizing aging conditions of polyurethane sealants

Abstract

The effectiveness of using ATR to study the chemical structure of various polyurethane formulations designed as joint sealants on building facades is discussed. Sealants were formulated, batched and exposed to various aging conditions before mounted on ATR spectroscopy apparatus for monitoring. The study has shown that ATR is effective in characterizing the chemical structure in terms of physical cross-linking and conformation state. It is shown that although aging tends to occur in the surface section of a specimen it can contribute to the deterioration of the bulk mechanical properties. Significant differences in the chemical structure of sealants in the surface section and the interior region after thorough curing was shown. © 2000 Elsevier Science Ltd. All rights reserved.