Flow micro-calorimetry and diffuse reflectance Fourier transform infrared spectroscopy studies in filled polyurethane adhesives by using dimethyl adipate as a model compound

Interactions between nano-scale filler particles (precipitated calcium carbonate, carbon black and fumed silica) and model compounds (dimethyl adipate and butan-2-one) are quantified using flow micro-calorimetry (FMC) and diffuse reflectance Fourier transform infrared spectroscopy (DRFTIRS). Carbonyl groups of dimethyl adipate interact strongly with silanol groups on the fumed silica surface but weakly with the uncoated precipitated calcium carbonate. In general, higher surface area loading imparts high level of adsorption because of the nanofiller has more adsorption sites. Carbon black is an exception likely due to the less accessible surface groups and the presence of relatively important amount of micropores.