Abstract: A method for removing compounds in the gaseous aggregate state from PLA-containing products in the viscous aggregate state by means of a thin-film evaporator. The compounds may be present in the liquid or solid aggregate state in the products under standard conditions. The invention further relates to a polylactide resin prepared in accordance with the method of the invention.

Abstract: A method for removing compounds in the gaseous aggregate state from PLA-containing products in the viscous aggregate state by means of a thin-film evaporator. The compounds may be present in the liquid or solid aggregate state in the products under standard conditions. The invention further relates to a polylactide resin prepared in accordance with the method of the invention.

Abstract: In a practicable continuous or batchwise process for the preparation of a crystallizable polylactic acid mixture, lactic acid may be polycondensed to yield an oligomer, which may then be depolymerized to yield a crude lactide. The crude lactide may be purified to yield a pure lactide, wherein fractionation may be carried out in the purification into an L- or D-lactide-rich fraction and also a meso-lactide-rich fraction. Subsequently a separate ring-opening polymerization of the resulting lactide fractions can be carried out. The individual polylactic acid batches or streams generated by the ring-opening polymerization may then be mixed. The present disclosure further relates to apparatuses for carrying out such processes and polylactic acid mixtures.

Abstract: The present invention relates to a device and also to a method for separating and recovering a cyclic diester, in particular dilactide or glycolide from polymer melts which include the cyclic diester as impurity. The device and also the method according to the invention allow recovery of the cyclic diester with a high yield and at the same time high purity.

Abstract: A method may facilitate the crystallization of granules of a crystallizable thermoplastic material in conjunction with removal of low molecular mass components contained in the thermoplastic material. The crystallizable thermoplastic material may have a crystalline melting temperature of at least 130° C. According to the method, a crystallization stage and a removal stage may be performed at different temperatures of the granules. Often the crystallization may occur at a lower temperature than the removal of the low molecular mass components. In the crystallization and removal stages, a flow of gas may pass countercurrent to a direction along which the granules are conveyed. Further, example devices disclosed herein may be utilized to perform the exemplary methods disclosed herein.

Abstract: In a practicable continuous or batchwise process for the preparation of a crystallizable polylactic acid mixture, lactic acid may be polycondensed to yield an oligomer, which may then be depolymerized to yield a crude lactide. The crude lactide may be purified to yield a pure lactide, wherein fractionation may be carried out in the purification into an L- or D-lactide-rich fraction and also a meso-lactide-rich fraction. Subsequently a separate ring-opening polymerization of the resulting lactide fractions can be carried out. The individual polylactic acid batches or streams generated by the ring-opening polymerization may then be mixed. The present disclosure further relates to apparatuses for carrying out such processes and polylactic acid mixtures.

Abstract: The present invention relates to a device and also to a method for separating and recovering a cyclic diester, in particular dilactide or glycolide from polymer melts which include the cyclic diester as impurity. The device and also the method according to the invention allow recovery of the cyclic diester with a high yield and at the same time high purity.

Abstract: A mixture of cyclic diesters derived from lactic acid and in cases a mixture of a racemate of dilactide may be produced in several different processes. In some instances, the process can thereby start from the corresponding alpha-hydroxycarboxylic acids, the corresponding cyclic diesters or oligomers of the corresponding alpha-hydroxycarboxylic acids.

Abstract: The present invention relates to a device for separating a biodegradable, intermolecular cyclic diester of an alpha-hydroxycarboxylic acid from material mixtures which contain in addition the alpha-hydroxycarboxylic acid of the diester corresponding thereto. In particular, the diester is thereby dilactide and the acid lactic acid. Furthermore, the present invention relates to a method for separating dilactide from material mixtures, which is based on a modified, distillative method. In addition, the present invention describes a polymerization device, in particular for preparing polylactide. Likewise, purposes of use of both the devices and of the method are indicated.

Abstract: Disclosed is a test and test apparatus used to determine whether lactic acid is suitable for polymerization.

Abstract: The present invention relates to a condensation and washing device with which in particular the process vapors which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerization device for the production of polylactide and also to a method for processing process vapors which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.

Abstract: The present invention relates to a device for separating a biodegradable, intermolecular cyclic diester of an alpha-hydroxycarboxylic acid from material mixtures which contain in addition the alpha-hydroxycarboxylic acid of the diester corresponding thereto. In particular, the diester is thereby dilactide and the acid lactic acid. Furthermore, the present invention relates to a method for separating dilactide from material mixtures, which is based on a modified, distillative method. In addition, the present invention describes a polymerisation device, in particular for preparing polylactide. Likewise, purposes of use of both the devices and of the method are indicated.

Abstract: The present invention relates to a device for separating a biodegradable, intermolecular cyclic diester of an alpha-hydroxycarboxylic acid from material mixtures which contain in addition the alpha-hydroxycarboxylic acid of the diester corresponding thereto. In particular, the diester is thereby dilactide and the acid lactic acid. Furthermore, the present invention relates to a method for separating dilactide from material mixtures, which is based on a modified, distillative method. In addition, the present invention describes a polymerization device, in particular for preparing polylactide. Likewise, purposes of use of both the devices and of the method are indicated.

Abstract: The present invention relates to a condensation and washing device with which in particular the process vapours which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerisation device for the production of polylactide and also to a method for processing process vapours which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.

Abstract: The present invention relates to a condensation and washing device with which in particular the process vapors which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerization device for the production of polylactide and also to a method for processing process vapors which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.

Abstract: The present invention relates to a polymerization reactor for continuous polymerization, the reactor being constructed in two stages and comprising a prepolymerization stage which is configured as a stirred vessel or as a loop-type bubble column and also a main polymerization stage which is configured as a tubular reactor. Furthermore, the present invention relates to a method for the production of biodegradable polyester, in particular polylactide, the reactor according to the invention being used. Likewise, the invention relates to a polymerization device which comprises further components in addition to the polymerization reactor.

Abstract: The present invention relates to a method for storing and/or transporting intramolecular cyclic esters (lactones), in particular lactide.

Abstract: A mixture of cyclic diesters derived from lactic acid and in cases a mixture of a racemate of dilactide may be produced in several different processes. In some instances, the process can thereby start from the corresponding alpha-hydroxycarboxylic acids, the corresponding cyclic diesters or oligomers of the corresponding alpha-hydroxycarboxylic acids.

Abstract: The present invention relates to a polymerisation reactor for continuous polymerisation, the reactor being constructed in two stages and comprising a prepolymerisation stage which is configured as a stirred vessel or as a loop-type bubble column and also a main polymerisation stage which is configured as a tubular reactor. Furthermore, the present invention relates to a method for the production of biodegradable polyester, in particular polylactide, the reactor according to the invention being used. Likewise, the invention relates to a polymerisation device which comprises further components in addition to the polymerisation reactor.

Abstract: The present invention relates to a condensation and washing device with which in particular the process vapours which occur during the production of polylactide can be processed and cleaned. Furthermore, the present invention relates to a polymerisation device for the production of polylactide and also to a method for processing process vapours which occur during the production of polylactide; possibilities for use of both the condensation and washing devices and of the method are likewise mentioned.