US Patent 10570249 Process for preparing polyalkenamers for packaging applications

A process for producing cycloalkenamer-containing compositions involves converting at least one cycloalkene by ring-opening metathetic polymerization to obtain a polyalkenamer-containing product mixture. The product mixture is worked up to remove monomers and oligomers of the cycloalkenes to obtain the polyalkenamer-containing composition by extraction with CO2. The extraction involves at least two stages: an extraction with liquid CO2 under the supercritical conditions, and then an extraction with supercritical CO2. Such cycloalkenamer-containing compositions can be used, for example, in the field of packaging materials, especially for food and drink.