Abstract: There is described a process for preparing a biodegradable polyester from an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and a diol where in a first reaction step the aromatic acid is esterified with the diol, and in a second reaction step the aliphatic acid is added to the reaction mixture. Furthermore, there is described an apparatus for carrying out this process.

Abstract: A process for reducing the amount of hydroxyl-end-groups of a polyester, wherein the polyester is prepared from at least one dicarboxylic acid and at least one dihydroxy alcohol, and at least one additive selected from the group consisting of carboxylic acid anhydride and mono-isocyanate, and wherein the additive is added during a step of prepolycondensation and/or during a step of polycondensation and/or after a step of polycondensation.

Abstract: A method and a device for admixing additives into a polymer melt made of non-extracted polyamide 6 are disclosed. The polymer melt is combined in a highly concentrated form with an additional melt flow without additives and mixed therewith. Additionally, a part of the melt is branched off from a main melt flow (3), wherein the sub-melt flow (4) is transported into a dispersing device (5) and is supplied and mixed with one or more additives (12). The side-melt flow (4) with additives is then returned into the main melt flow (3), mixed with the main melt flow, and subsequently supplied for further processing.

Abstract: There is described a process for preparing a biodegradable polyester from an aromatic dicarboxylic acid, an aliphatic dicarboxylic acid and a diol where in a first reaction step the aromatic acid is esterified with the diol, and in a second reaction step the aliphatic acid is added to the reaction mixture. Furthermore, there is described an apparatus for carrying out this process.

Abstract: The application relates to a process for reducing the amount of hydroxyl-end-groups of polyesters, wherein the polyester is prepared from at least one dicarboxylic acid and at least one dihydroxy alcohol, and at least one additive selected from the group consisting of dicarboxylic acid anhydride and/or monoisocyanate is added during and/or after the process of preparing the polyester.

Abstract: A method and a device for admixing additives into a polymer melt made of non-extracted polyamide 6 are disclosed. The polymer melt is combined in a highly concentrated form with an additional melt flow without additives and mixed therewith. Additionally, a part of the melt is branched off from a main melt flow (3), wherein the sub-melt flow (4) is transported into a dispersing device (5) and is supplied and mixed with one or more additives (12). The side-melt flow (4) with additives is then returned into the main melt flow (3), mixed with the main melt flow, and subsequently supplied for further processing.