Abstract: Disclosed is a test and test apparatus used to determine whether lactic acid is suitable for polymerization. The test apparatus comprises a) means for the polycondensation of the lactic acid to form a pre-polymer, b) means for depolymerization of the prepolymer to form dilactide, and c) means for carrying out analytical methods to determine at least one of the dilactide yield and/or the racemization, wherein lactic acid which is suitable for polymerization exhibits a dilactide yield of >90% and a racemization of <5%.

Abstract: The present invention relates to a method for the production of aliphatic polyesters in a two-step method. There are thereby added, in a first step, to a precondensate of an aliphatic dicarboxylic acid or to a mixture of aliphatic dicarboxylic acids and an aliphatic dialcohol or to a mixture of aliphatic dialcohols, further monomeric components, i.e. further aliphatic dicarboxylic acids and also a further aliphatic dialcohol, a polyester prepolymer being obtained. In a further step, polycondensation of the prepolymer obtained in the first step is effected.

Abstract: The invention relates to a method and device for the direct production of polyester granulate from a highly viscous polyester melt with a polymerization degree of 132 to 165, as well as the granulates formed thereform. In the method, the highly viscous polyester melt is subjected to a pre-drying and drying/degassing after a hot cutting method. Hot cutting is implemented at water temperatures of 70° C. to 95° C. and with a liquid to solid ratio of 8 to 12:1.

Abstract: The present invention is directed to a method for the production of a titanium containing catalyst, wherein a titanium-(IV)-alkoxide of high purity is reacted with an alpha-hydroxy carboxylic acid. Furthermore the invention concerns a titanium containing catalyst allowing for the production of high viscosity polyesters with high thermal stability. In addition, the invention is directed to a method for the production of polyesters and polyesters themselves.

Abstract: The invention relates to a reactor in the form of a VK tube (VK: simplified continuous), for the polymerisation of polyamides, the reactor being subdivided into an upper and lower reactor region, which are controllable independently of each other. Likewise, the invention relates to a method for the production of polyamides in which such a reactor is used.

Abstract: The invention relates to a method and device for the direct production of polyester granulate from a highly viscous polyester melt with a polymerisation degree of 132 to 165, as well as the granulates formed thereform. In the method, the highly viscous polyester melt is subjected to a pre-drying and drying/degassing after a hot cutting method. Hot cutting is implemented at water temperatures of 70° C. to 95° C. and with a liquid to solid ratio of 8 to 12:1.

Abstract: The present invention relates to a polymerisation device for the production of melts of thermoplastic polymers in which the heat of the discharged product can be recovered and used for preheating of the usable raw materials. In addition, the present invention relates to a corresponding method for the production of thermoplastic polymers.

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: The invention relates to an additive having at least two functionalities being able to undergo a condensation reaction in combination with a tetraalkylpiperidinyl radical and also a tertiary amine functionality. By the combination of these functionalities, a universal additive can be provided, which, on the one hand, makes possible a narrower molar mass distribution and, at the same time, improves the performance for spun polymers. According to the invention, likewise corresponding additivated polyamide moulding compounds and also an additive solution are provided. The additives according to the invention are used in particular in the production of polyamide for textile applications.

Abstract: The invention relates to a conveying device for conveying granular material that is stored in a source (10), for example polyamide 6 (PA6) granules, to multiple receiving points (11,12,13, . . . ), the conveying device having a number of injectors (11,12,13, . . . ) corresponding to the number of receiving points. Also disclosed is a method for conveying granular material, for example PA6 granules, from a source (10) to multiple receiving points.

Abstract: The invention relates to a method for the production of a high-molecular polyester or copolyester which comprises at least three method steps. In a first method step, a paste is produced from at least one aromatic dicarboxylic acid or the diester thereof or the acid anhydride thereof and also from at least one aliphatic dicarboxylic acid or the diester thereof or acid anhydride thereof and also from at least one dialcohol and also the required quantity of transesterification- or polycondensation catalyst. This paste is converted into a prepolymer in a second step at increased temperature and, in the third method step, this obtained prepolymer is polycondensed or copolycondensed at reduced pressure relative to normal conditions. The implementation of the method can be effected continuously and also discontinuously. Furthermore, the invention relates to polyesters and copolyesters produced in this way and also to biodegradable polymer blends comprising these.

Abstract: The present invention relates to a method for the production of cyclic carboxylic acid esters, in particular intramolecular lactones, such as e.g. dilactide, the production of these cyclic esters from oligomeric carboxylic acids being effected by cyclising depolymerisation. During this reaction, a condensation product of these oligomeric carboxylic acids is produced as by-product, i.e. a mixture of higher-molecular oligomeric carboxylic acids which are hydrolysed in a further step and hence recovered. This hydrolysate can be added again to the cyclising depolymerisation which is implemented in the first step.

Abstract: The present invention relates to a method for the production of aliphatic polyesters in a two-step method. There are thereby added, in a first step, to a precondensate of an aliphatic dicarboxylic acid or to a mixture of aliphatic dicarboxylic acids and an aliphatic dialcohol or to a mixture of aliphatic dialcohols, further monomeric components, i.e. further aliphatic dicarboxylic acids and also a further aliphatic dialcohol, a polyester prepolymer being obtained. In a further step, polycondensation of the prepolymer obtained in the first step is effected.

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: The present invention relates to increasing the molecular weight during a thermal treatment of polyester in combination with a latent heat granulation. With the newly-developed method, an SSP (Solid State Postcondensation) can be directly combined with an underwater granulation. The method differs from a conventional solid state postcondensation by an increase in the molecular weight being possible without additional heat input and hence only by using the residual heat and the crystallization heat present. A characterizing element is improved water separation and dehumidification during the granulation. Only in this way is an increase in viscosity possible even with a small granulate of an average particle weight less than 20 mg.

Abstract: The present invention relates to a process for recovering lactide from polylactide (PLA) or glycolide from polyglycolide (PGA), in which, in a first step, PLA or PGA is contacted with a hydrolysing medium and hydrolytically degraded to oligomers. In a further step, a cyclising depolymerisation of the oligomers obtained in the first step is effected to give lactide or glycolide. In addition, the present invention relates to an apparatus based on the combination of a hydrolysis apparatus with a depolymerisation reactor, with which the above-described process can be performed. The core of the process according to the invention is a partial hydrolysis of the polymeric materials originally used in combination with a cyclising depolymerisation.

Abstract: The invention relates to a method for the continuous production of a solution of salts, in particular for the production of hexamethylenediamine adipate and a device for implementing such a method. According to the invention, it is proposed to convert, in a first step, a substoichiometric quantity of alkane diamine in a ratio to the alkane dicarboxylic acid in water and, in a subsequent second step, to implement making-up with alkane diamine, adjustment of the stoichiometric ratios being effected via a pH value measurement at a constant temperature.

Abstract: The invention relates to a method for direct, continuous modification of polymer melts with additives in the side stream and is distinguished by a very high degree of flexibility in product change-overs.

Abstract: The present invention relates to a method of removing an absorbate from gases or gas mixtures containing absorbate, in which the gas or gas mixture is contacted by a liquid mixture of absorption agent and absorbate or of liquid absorbate-free absorption agent, wherein the absorbate is absorbed at least partially by the liquid mixture of absorption agent and absorbate and is concentrated therein or is absorbed by the liquid absorbate-free absorption agent while forming a liquid mixture of absorption agent and absorbate. It is characteristic in the method in accordance with the present invention that the absorption agent used and the absorbate used have a miscibility gap.