IDENTIFICATION OF FIBER/MATRIX INTERPHASE OF UNIDIRECTIONAL COMPOSITES (GLASS FIBER/EPOXY) WITH GRADIENT IN CROSSLINK DENSITY BY MEANS OF DYNAMIC MECHANICALTHERMAL ANALYSIS (DMTA)

Tóm tắt

This study was carried out on unidirectional composite samples (epoxy/glass fiber) with gradient in crosslink density in the 250 µm from the surface contacting with the air during manufacturing. The tan delta spectrum of the composite was determined by a DMA in three point bending modes (single cantilever). In parallel, the tan delta spectra of the epoxy-amine resin samples were also determined under the same conditions. The fiber/matrix interphase was determined by comparing the tan delta spectra of resin and composite by using Origin software. Results also show that the formed interphase is hydrophilic and has uncompleted crosslinked networks. However, its micro-structure and chemical nature are different from the matrix at the surface contacting with the air that are uncompleted crosslinked networks.