An infrared spectroscopic investigation of the curing reactions of the EPON 828/meta-phenylenediamine system
✍ Scribed by David W. Schiering; J. E. Katon; L. T. Drazal; V. B. Gupta
- Publisher
- John Wiley and Sons
- Year
- 1987
- Tongue
- English
- Weight
- 467 KB
- Volume
- 34
- Category
- Article
- ISSN
- 0021-8995
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✦ Synopsis
Mid-and near-infrared (IR) spectroscopy has been used to study the curing of a bisphenol-A based epoxy resin (EPON-828) with a tetrafunctional curing agent, viz., meta-phenylenediamine (MPDA). Three different cure cycles were used in the study. Primary amine functionality was observed to react relatively rapidly; none remained after curing for 2 h at 75°C. Secondary amine functionality was exhausted in epoxy rich samples subjected to the standard cure cycle (2 h a t 75°C followed by 2 h at 125°C). In samples with stoichiometric amount or higher MPDA, complete reaction of secondary amine or epoxy groups was not observed. In amhe-rich samples subjected to post curing (6 h at 175"C), evidence was seen for the reaction of hydroxyl and epoxy groups, resulting in a considerable increase in the crosslink density of these samples.