Characterization of epoxy resin surface energetics

Surface Energetics Evolution during Processing of Epoxy Resins

“…However, the tendency seems to be in agreement with the chemical structure and composition of both systems. A higher density of strong interactions has been found in the modified TGMDA system and has been attributed to the higher concentration of amines (4).…”

“…For example, a change in structural groups during curing might affect the "interacting element" and, thus, its molar mass. However, the definition and interpretation (4). The values indicated for the fully cured solid epoxy are the Lifshitz-van der Waals components of the surface energy.…”

“…Surface tension measurements were successfully performed using DCA in a previous study (4). The technique is based on the measurement, during immersion and emersion of a solid, of the downward force exerted by the surface tension of a wetting liquid on a solid partially immersed using the Wilhelmy method (21), so that the difference in weight between the solid suspended in the air and that in the probe liquid is…”

“…The molecular interactions and, therefore, the surface energetics are known to be temperature dependent (3). In a previous paper (4), it was found that the liquid surface tension of two different epoxy systems decreases with temperature following a linear regression, as has been shown for many other liquids (3) and molten polymers (5). However, the time evolution of the surface energetics throughout the entire 1 To whom correspondence should be addressed.…”

“…The viscosity of the epoxy strongly increases with time during measurements, indicating that viscous effects also increase and are therefore dramatically overestimating the values of surface tension. Based on Hoffman (17) and Kistler (18), corrections for viscous effects on surface tension measurements have previously been proposed (4) and are applied here. However, measurements can be performed only until the resin viscosity becomes too high to allow rapid surface deformation.…”