SOLVENT SYSTEM FOR THE FRACTIONATION OF PVC PLASTIC BY LIQUID-LIQUID EXTRACTION

Abstract

The present invention relates to a solvent system specifically designed for the liquid-liquid extraction fractionation, particularly by centrifugal partition chromatography, of a PVC-based feed comprising a PVC polymer and at least one additive. The system comprises two immiscible liquid phases, A and B, each containing an organic solvent or a mixture of organic solvents selected from a list consisting of ketones, amides, azines, esters, ethers, halogenated solvents, hydrocarbons, sulfide solvents, and dihydrolevoglucosenone. The partition coefficient of the PVC polymer in the solvent system (ratio of the mass concentrations of PVC polymer dissolved in phase B and in phase A) tends toward zero, and the partition coefficient of the additive in the solvent system (ratio of the mass concentrations of the additive dissolved in phase B and in phase A) is greater than or equal to 0.05.