(323d) Multi-Scale Modeling of Ionic Liquid Dispersed Nanoparticles in Epoxy Resin

Epoxy resins boast impressive rigidity, thermal and electrical resistance, and an easily controlled casting process. Unmodified, however, such resins are generally brittle. By dispersing a second phase that minimally disrupts the underlying epoxy matrix the fracture toughness of the material can be increased.

Nanoparticles, possessing a high surface area to volume ratio, are often excellent fillers for such systems. Depending on their interactions with the epoxy matrix, such particles can offer improvement in material properties even at small volume fractions. Our recent work has demonstrated that ionic liquids can simultaneously disperse nanoparticles within an epoxy matrix and initiate epoxy cure reaction. This results in materials with potentially unique interphase properties resulting from interactions among the nanoparticle surface, ionic liquid, and epoxy resin.

This study examines those interactions experimentally and conceptually. Epoxy synthesized over a range of nanoparticle and ionic liquid volume fractions are analyzed for glass transition and mechanical properties. Kinetic rate constants and diffusion coefficients are obtained using time-resolved Fourier Transform Infrared Attenuated Total Reflectance Spectrometry (FTIR-ATR). From these parameters and the properties of the cured material, an attempt is made to link the cure behavior of this complex system to the material behavior characteristics.