mz9b00508_si_001.pdf (838.29 kB)
In Situ Vibrational Probes of Epoxy Gelation
journal contribution
posted on 2019-07-23, 12:03 authored by Lérys Granado, Stefan Kempa, Laurence John Gregoriades, Frank Brüning, Anne-Caroline Genix, Jean-Louis Bantignies, Nicole Fréty, Eric AnglaretThis
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.