Monitoring in-situ dissolution of polystyrene-acrylonitrile (SAN) via calorimetry and spectroscopy

• Dissolution of SAN in MEK was followed by FTIR spectroscopy and calorimetry. • The enthalpy of dissolution is dominated by the glassy to rubbery transition. • The kinetic of dissolution is governed by the diffusion of solvent. Dissolution/precipitation recycling is an environmentally friendly solution that could be potentially implemented for ABS recycling. In this paper, a set of useful calorimetric, spectroscopic, and rheological techniques and methods are presented to monitor in-situ the dissolution of the ABS matrix: poly(styrene-acrylonitrile) (SAN). In line with the Hansen solubility parameters, methyl ethyl ketone (MEK) has been selected to be a suitable solvent for SAN dissolution. Thermodynamic and kinetic aspects of the dissolution process were investigated by using calorimetry and in-situ ATR-FTIR spectroscopy. Through an isoconversional method, the effective activation energy and the main steps involved in the dissolution process were determined. A rheological characterization of the solution SAN-MEK was also performed to provide further information on the rheological behavior.