Abstract: A simple, low cost, environmentally friendly and sustainable process for the production of internal dehydration products of hydrogenated sugar, implementing trivalent metal phosphate (metal (III) phosphates) as catalysts during the dehydratation step.

Abstract: A process for manufacturing a polycarbonate, having a glass transition temperature greater than or equal to 50° C., includes: a step (1) of introducing into a reactor a monomer of formula (I) and R1 and R2 being identical or different alkyl groups; a step (2) of introducing into the reactor at least one cyclic diol or a mixture of diols (B) including at least 20 mol % of cyclic diols; a subsequent step (3) of polycondensation via transesterification of the mixture of monomers including the monomers (A) and (B); a step (4) of recovering the polycarbonate formed during step (3).

Abstract: A method for oxidizing 5-hydroxymethyl furaldehyde, includes at least one step of oxidation in the presence of an organic acid, a nitroxyl radical, an oxygen source, and an oxygen transfer agent.

Abstract: A process for manufacturing polycarbonate includes:—a step (1) of introducing into a reactor a particular composition (A) of at least one dianhydrohexitol carbonate bearing two alkyl carbonate functions; a step (2) of introducing a diol or a mixture of diols (B); a subsequent step (3) of polycondensation by transesterification of the mixture of monomers including (A) and (B); a step (4) of recovering the polycarbonate formed during step (3).

Abstract: A dianhydrohexitol packaged in a packaging material that is impervious to gas, wherein the partial pressure of oxygen inside the packaging is 0.1 to 10 mbar, preferably 0.5 to 5 mbar, and more preferably 0.5 to 2 mbar. The method for packaging dianhydrohexitol, includes inserting the dianhydrohexitol into a packaging material that is impervious to gas, and then hermetically sealing the packaging, the method being carried out in an atmosphere that has a partial pressure of oxygen of 0.1 to 10 mbar, preferably 0.5 to 5 mbar, and more preferably 0.5 to 2 mbar.

Abstract: A process for manufacturing polycarbonate includes:—a step (1) of introducing into a reactor a particular composition (A) of at least one dianhydrohexitol carbonate bearing two alkyl carbonate functions; a step (2) of introducing a diol or a mixture of diols (B); a subsequent step (3) of polycondensation by transesterification of the mixture of monomers including (A) and (B); a step (4) of recovering the polycarbonate formed during step (3).

Abstract: A process for manufacturing a polycarbonate, having a glass transition temperature greater than or equal to 50° C., includes: ? a step (1) of introducing into a reactor a monomer of formula (I) and R1 and R2 being identical or different alkyl groups; ? a step (2) of introducing into the reactor at least one cyclic diol or a mixture of diols (B) including at least 20 mol % of cyclic diols; ? a subsequent step (3) of polycondensation via transesterification of the mixture of monomers including the monomers (A) and (B); ? a step (4) of recovering the polycarbonate formed during step (3).

Abstract: Dianhydrohexitol pellets, whose fluidity is preserved even after lengthy storage, include between 90% and 100%, preferably between 95% and 100%, and more preferentially between 97% and 100% of dianhydrohexitols by weight, on a dry weight basis, and have the particularity of not being subject to caking. A process for preparing the dianhydrohexitol pellets is also described.

Abstract: A method for preparing dialkyl carbonates of dianhydrohexitol, includes the following steps: (a) preparing an initial reaction mixture containing at least one dianhydrohexitol, at least two mole equivalents of a dialkyl carbonate of formula and a transesterification catalyst; (b) heating the reaction mixture to a temperature greater than or equal to the boiling temperature of the formed alcohol, or of the azeotrope thereof, in a reaction chamber preferably provided with a rectification column including a sufficient number of theoretical distillation plates to separate the resulting alcohol from the reaction mixture. Certain dialkyl carbonates of dianhydrohexitols produced by the method and the use thereof for synthesizing synthetic polymers are also described.

Abstract: A method for preparing dialkyl carbonates of dianhydrohexitol, includes the following steps: (a) preparing an initial reaction mixture containing at least one dianhydrohexitol, at least two mole equivalents of a dialkyl carbonate of formula and a transesterification catalyst; (b) heating the reaction mixture to a temperature greater than or equal to the boiling temperature of the formed alcohol, or of the azeotrope thereof, in a reaction chamber preferably provided with a rectification column including a sufficient number of theoretical distillation plates to separate the resulting alcohol from the reaction mixture. Certain dialkyl carbonates of dianhydrohexitols produced by the method and the use thereof for synthesizing synthetic polymers are also described.

Abstract: A method for preparing a polycarboxylic composition, includes a stage in which a monosaccharide composition undergoes an electrochemical oxidation treatment carried out in the absence of sodium hypochlorite and in the presence of a) an amine oxide and b) a carbon-based anode. Preferably, the anode is selected from the group comprising carbon felt and granular active carbon. The electrochemical oxidation treatment can be carried out advantageously at a pH, preferably of between 11.5 and 14. The method makes it possible to obtain novel products, especially 2-carboxy-2, 3, 4-trihydroxypentane-dioicious acid, the salts and derivatives thereof.

Abstract: A method for preparing a polycarboxylic composition, includes a stage in which a monosaccharide composition undergoes an electrochemical oxidation treatment carried out in the absence of sodium hypochlorite and in the presence of a) an amine oxide and b) a carbon-based anode. Preferably, the anode is selected from the group comprising carbon felt and granular active carbon. The electrochemical oxidation treatment can be carried out advantageously at a pH, preferably of between 11.5 and 14. The method makes it possible to obtain novel products, especially 2-carboxy-2,3,4-trihydroxypentane-dioicious acid, the salts and derivatives thereof.