- In Situ Vibrational Probes of Epoxy Gelation doi link

Auteur(s): Granado Lérys, Kempa Stefan, Gregoriades Laurence John, Brüning Frank, Genix A.-C., Fréty Nicole, Anglaret E., Bantignies J.-L.

(Article) Publié: Acs Macro Letters, vol. 8 p.984-988 (2019)

Ref HAL: hal-02290446_v1
DOI: 10.1021/acsmacrolett.9b00508
WoS: 000482521100019
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This paper presents an efficient way to measure the curing kinetics and gel point, αgel, in epoxy resins from one single experiment. The epoxy curing reaction is herein monitored using in situ and time-resolved near-infrared absorption spectroscopy (NIR). The curing profiles over different isothermal conditions are in good agreement with DSC. Furthermore, the increase of the NIR absorption bands of aromatic rings (unreactive throughout curing) probe the cure shrinkage, as more and more aromatic rings are localized within the fixed sample volume. Therefore, the gel point is determined using the onset of the aromatic absorption increase. The results are in good agreement with the theoretical gel point, as well as DMA results. This innovative approach enables gelation measurements on epoxy neat resins and film composites with an easy-to-perform, accurate, robust, and versatile method.