Polyether polyol/CO2 solutions: Solubility, mutual diffusivity, specific volume and interfacial tension by coupled gravimetry-Axisymmetric Drop Shape Analysis

In this work we investigate the sorption of CO2 in a formulated polyether polyol, typically used to obtain rigid polyurethane foams when it reacts with isocyanates. In particular, by using a fully-experimental, coupled gravimetry-Axisymmetric Drop Shape Analysis, solubility, mutual diffusivity, specific volume and interfacial tension of polyol/CO2 solutions have been measured at 35 C and at CO2 pressures up to 8000 kPa. CO2-treated polyol was also subjected to Gel Permeation Chromatography (GPC) and Fourier Trans- form Infrared (FT-IR) spectroscopic analysis to evaluate the effect of the high-CO2 pressure treatment. The results show quite a large CO2 solubilization (up to 17% ca. in the examined experimental range), in turn responsible for a moderate swelling of the polymer and an extensive effect on the interfacial ten- sion, which reaches vanishing values at the highest investigated pressure.