Abstract: Process for recovering a polymer by injection of steam, and optionally liquid water, into a solution of this polymer comprising a polar aprotic organic solvent (PAOS) that has an azeotrope with water and an apolar organic compound that is miscible with the PAOS and immiscible with water and that acts as a phase separation agent (PSA), the boiling point of which is below that of the water/PAOS azeotrope, the amount of steam injected being sufficient to give rise to the substantial removal of the PSA via stripping and that of the PAOS via azeotropic distillation, and the total amount of water being sufficient to give rise to the precipitation of the polymer, this process being characterized in that the polymer solution also comprises an alcohol, at least during the precipitation of the polymer.

Abstract: Method for recovering a polymer from a liquid medium (1) substantially containing the polymer and a solvent for the latter, wherein: (a) this liquid medium (1) is injected into a reactor (2) containing a stirred substantially monophase liquid mixture comprising a major fraction by weight of a non-solvent and a minor fraction by weight of a solvent, the mixture having a composition and temperature such that the polymer precipitates therefrom progressively; (b) the polymer is recovered in the form of particles in suspension (5) in a liquid rich in non-solvent; (c) the polymer particles (9) are separated from the liquid.

Abstract: Process for recovering a polymer by injection of steam, and optionally liquid water, into a solution of this polymer comprising a polar aprotic organic solvent (PAOS) that has an azeotrope with water and an apolar organic compound that is miscible with the PAOS and immiscible with water and that acts as a phase separation agent (PSA), the boiling point of which is below that of the water/PAOS azeotrope, the amount of steam injected being sufficient to give rise to the substantial removal of the PSA via stripping and that of the PAOS via azeotropic distillation, and the total amount of water being sufficient to give rise to the precipitation of the polymer, this process being characterized in that the polymer solution also comprises an alcohol, at least during the precipitation of the polymer.

Abstract: A process for the purification of a vinyl chloride polymer containing a compound of a heavy metal by: (a) dissolving the PVC in a solvent; (b) treating the solution with at least one additive capable of adsorbing or of forming a complex with the compound of the heavy metal; (c) centrifuging the treated solution to precipitate the adsorbed or complexed compound of the heavy metal; and (d) separating the precipitate from the PVC solution.

Abstract: Method for recovering a polymer from a liquid medium (1) substantially containing the polymer and a solvent for the latter, wherein: (a) this liquid medium (1) is injected into a reactor (2) containing a stirred substantially monophase liquid mixture comprising a major fraction by weight of a non-solvent and a minor fraction by weight of a solvent, the mixture having a composition and temperature such that the polymer precipitates therefrom progressively; (b) the polymer is recovered in the form of particles in suspension (5) in a liquid rich in non-solvent; (c) the polymer particles (9) are separated from the liquid.

Abstract: Process for the purification of a vinyl chloride polymer (PVC) comprising at least one compound of a heavy metal, according to which: (a) the PVC is dissolved in a solvent; (b) the solution is treated with at least one additive capable of adsorbing or of forming complexes with the compound of the heavy metal; (c) the solution treated is subjected to centrifuging, so as to precipitate the adsorbed or complexed compound of the heavy metal; and (d) the precipitate is separated from the PVC solution.

Abstract: Process for recovering a vinyl alcohol polymer in solution in a solvent, according to which: (a) the polymer solution is converted into a gel (b) water is added to the gel obtained (c) the gel is broken mechanically to form polymer particles suspended in a liquid comprising the solvent and water. Particles obtained according to this process and multilayer fuel tank comprising in the barrier layer the EVOH obtained via this process.

Abstract: Process for the processing of a waste high density polyethylene (HDPE) in particulate form by extrusion-blow moulding, according to which the waste HDPE is extruded as a blend with a polyfunctional epoxide and the extrudate is subsequently subjected to a blow moulding operation.