Abstract: A process for continuous or discontinuous synthesis of elastomeric copolyesters from polybutylene terephthalate (PBT) and polyoxytetramethylene glycol is described in which the tetrahydrofuran (THF) obtained as a byproduct in synthesis of polybutylene terephthalate from 1,4-butanediol is rectified and then reacted by ring-opening polymerization to form polyoxytetramethylene glycol which condenses with the free or esterified carboxyl groups of PBT to form the copolyester, whereby chain termination and catalyst deactivation are accomplished by adding 1,4-butanediol without separating the catalyst.

Abstract: The invention relates to a method for generating a vacuum and for separating volatile compounds during esterification, transesterification and/or polycondensation reactions. One or several jets of steam comprising a spray condenser, which is arranged up or downstream, are connected to the suction side of a reactor which is to be evacuated and phenol or steam containing phenol is used as propellant steam at a pressure of 0.5 hPa to approximately 1.5 MPa and liquid phenol or a liquid containing phenol is used as a spraying agent.

Abstract: The invention relates to a method for the treatment of waste containing polyamide comprising a) depolymerisation of the waste containing polyamide, whereby a caprolactam raw material (6) and a flow (3), comprising the secondary constituents and additives from the depolymerisation, are obtained, and b) leaching of the flow (3) at least once using an extracting agent.

Abstract: The invention relates to a method for the analysis of refuse objects (2) containing polymers, in particular of carpets, in a recycling plant (1) and an automatic analytical device (7). In order to determine the polymer constituents of the refuse object (2), according to the invention, part of the refuse object (2) is vaporised and examined by a mass spectrometer (18). Using the method according to the invention and the automatic analytical device according to the invention, the refuse objects (2) can be classified for further processing (9, 10, 11) more accurately and more reliably during transport on a conveyor device (6).

Abstract: A method is disclosed for producing a vacuum and for separating condensable components present in vapor which accumulates during the production of a polymer by melt-phase polycondensation under vacuum. Vapor produced during the production of polymers by melt-phase polycondensation in at least one reaction step under vacuum is drawn of by at least one steam jet vacuum pump with a down stream injection condenser. The steam jet vacuum pump is driven with alkylene carbonate in vapor form and liquid alkylene carbonate is then supplied to the injection condenser as coolant.

Abstract: In a method for the continuous manufacture of polymers by means of melt condensation of a monomer in each case with itself or with at least one other monomer the molten monomers are esterified or transesterified in the presence of a catalyst, subsequently the esterification/transesterification product is fed for the precondensation to a disc ring reactor, then the precondensation product is fed to an LVS disc ring reactor for the polycondensation and finally the polycondensation product is fed to the end polycondensation.

Abstract: Comminuted carpet pieces are fed to a first stirred tank together with an aqueous solution containing separating salt, to form a first suspension, which is fed to a first mechanical separating stage. A first high-solids phase, a second high-solids phase containing polymer fiber material, and a liquid phase are obtained therefrom. The second high-solids phase is mixed with a water-containing separation solution in a stirred tank, to give a second suspension, which is fed to a second mechanical separating stage. A third high-solids phase, a polymer fiber material-rich phase and a liquid phase are withdrawn therefrom. An acid which is stronger than H2CO3 is introduced into the stirred tank together with the water-containing separation solution, and the pH of the liquid in the stirred tank is adjusted to 2–6.

Abstract: Polycarbonates are produced by reacting a monomeric carbonate component with at least one diphenol or dialcohol in the presence of a transesterification catalyst, wherein the molten component is mixed with the transesterification catalyst by stirring and a transesterification product is produced, which is polycondensated. For polycondensation, the transesterification product is passed through a preliminary reactor, at least one intermediate reactor and one final reactor, the reactors being connected in series and having a substantially horizontal driven shaft with stirrers attached thereto. It is ensured that in the preliminary reactor and in the final reactor a dwell time of the melt of 5 minutes to 2 hours is maintained, that the temperatures in the preliminary reactor are maintained in the range from 220 to 300° C. and in the final reactor in the range from 240 to 350° C.

Abstract: Polycarbonates are produced by reacting a monomeric carbonate component with at least one diphenol or dialcohol in the presence of a transesterification catalyst, wherein the molten component is mixed with the transesterification catalyst by stirring and a transesterification product is produced, which is polycondensated. For polycondensation, the transesterification product is passed through a preliminary reactor, at least one intermediate reactor and one final reactor, the reactors being connected in series and having a substantially horizontal driven shaft with stirrers attached thereto. It is ensured that in the preliminary reactor and in the final reactor a dwell time of the melt of 5 minutes to 2 hours is maintained, that the temperatures in the preliminary reactor are maintained in the range from 220 to 300° C. and in the final reactor in the range from 240 to 350° C.

Abstract: Process for generating a vacuum and separating the condensable components of the vapors of melt-phase polycondensation in the production of polycarbonate, where at least one or two vapor jets with a downstream spray condenser are connected to the intake side of the polycondensation reactor to be evacuated, and the motive vapor is diphenyl carbonate vapor, and the spray liquid is liquid diphenyl carbonate.

Abstract: A process for the reduction of the carboxyl end groups of linear polyester through reaction with alkylene carbonate in the melt phase in the presence of 40 to 160 ppm of allyltriphenyl phosphonium bromide, based on the weight of the polyester.