Effects of Storage Aging on the Properties of Epoxy Prepregs.
writer：Yu, Y. F.*; Su, H. H.; Gan, W. J.
keywords：near-infrared spectroscopy, quality, prepreg
source：期刊
specific source：Industrial & Engineering Chemistry Research 2009, 48, (9), 4340-4345.
Issue time：2009年
Changes in the properties of epoxy prepregs during storage are of both industrial and theoretical interest. It would be very helpful to have a test, suitable for production use, to determine when a prepreg has aged beyond acceptable limits. In this article, different epoxy prepregs aged under various conditions were studied by near-infrared (NIR) and mid-infrared (MIR) Fourier transform spectroscopies, dynamic mechanical analysis (DMA), rheological analysis, time-resolved light scattering (TRLS), and optical microscopy (OM). A very good relationship between storage aging time and curing conversion was obtained by NIR measurements. Furthermore, the rheological study showed that both the viscosity and the gelation time changed with storage aging. Changes in the glass transition temperatures of epoxy prepregs can result from either curing or phase separation during storage aging. The TRLS and OM results showed that structural evolution might occur during storage for some prepregs.