A process for preparing polycarbonate by the phase interface process in the presence of at least one catalyst, wherein immediately after the optionally first addition of the at least one catalyst, from 0.01 to 20 J/kg of mixing energy is introduced into the system comprising the at least one catalyst within a time of from 2 to 1200 s. A mixture, an organic phase, and a process for distributing at least one catalyst in a system comprising an organic phase and an aqueous phase are also disclosed herein.

A method of continuously producing a polyol includes: (i) feeding a solid catalyst into a continuous stirred tank reactor (CSTR); (ii) contacting a reaction mixture comprising one or more epoxides and carbon dioxide with the solid catalyst and a chain transfer agent comprising a plurality of sites capable of initiating copolymerization of epoxides and carbon dioxide in the CSTR; (iii) allowing polymerization reaction to proceed until a desired molecular weight polyol has formed; and (iv) terminating the polymerization reaction.

Techniques regarding the synthesis of polyesters and/or polycarbonates through one or more ring-opening polymerizations conducted within a flow reactor and facilitated by a urea anion catalyst and/or a thiourea catalyst are provided. For example, one or more embodiments can comprise a method, which can comprise polymerizing, via a ring-opening polymerization within a flow reactor, a cyclic monomer in the presence an organocatalyst comprising a urea anion.

Techniques regarding catalyzing one or more ring-opening polymerizations within one or more flow reactors using one or more organometallic bases are provided. For example, one or more embodiments described herein can comprise a method, which can include forming a polymer, via a ring-opening polymerization within a flow reactor, from a cyclic monomer in the presence of an organometallic base and a primary alcohol initiator.

A method of manufacturing a poly(ether-carbonate) polyol comprises a polymerization stage that includes polymerizing carbon dioxide and at least one alkylene oxide, with a starter, in the presence of a double metal cyanide polymerization catalyst and a catalyst promoter that is devoid of halide anions and cyanide. The catalyst promoter is separate from the double metal cyanide polymerization catalyst.

The present invention provides a process for removing gaseous constituents dissolved in liquid reaction mixtures in the copolymerization of alkylene oxide and carbon dioxide, characterized in that (η) prior to decompression the liquid reaction mixture has a pressure of 5.0 to 100.0 bar (absolute), wherein the following process stages are performed in the specified sequence: (i) decompression of the reaction mixture by at least 50% of the prevailing pressure, (ii) subsequent droplet separation with first defoaming and (iii) subsequent bubble separation with second defoaming to clarify the liquid phase, wherein the process stages (i) to (iii) are performed one or more times until the resulting reaction mixture has a pressure of 0.01 to <5.00 bar (absolute), and also a process for preparing polyethercarbonate polyols comprising the process stages (i)-(iii).

Techniques regarding catalyzing one or more ring-opening polymerizations within one or more flow reactors using one or more organometallic bases are provided. For example, one or more embodiments described herein can comprise a method, which can include forming a polymer, via a ring-opening polymerization within a flow reactor, from a cyclic monomer in the presence of an organometallic base and a primary alcohol initiator.

Techniques regarding the synthesis of one or more polymers through one or more ring-opening polymerizations conducted within a flow reactor and facilitated by one or more anionic catalysts are provided. For example, one or more embodiments can comprise a method, which can comprise polymerizing, via a ring-opening polymerization within a flow reactor, a cyclic monomer in the presence of one or more anionic organocatalysts.

The invention relates to a method for operating a production plant for producing a chemical product (1) by reacting a H-functional reactant (2) with phosgene (3) during an interruption in production when taking at least one plant part of the production plant out of operation, wherein low-oxygen and oxygen-rich phosgene-containing exhaust gas flows are directed separately from one another in different phosgene decomposition directions and separately from one another—at spatially different points—into a combustion device, wherein plant parts that have not been taken out of operation are operated in a closed-circuit operating mode. The invention also relates to a production plant for producing a chemical product by reacting H-functional reactants with phosgene, which is suitable for being operated with the method according to the invention.

In an embodiment, a reactor for carrying out a melt transesterification reaction at a reactor temperature of 160 to 300 C. and a reactor pressure of 5 to 200 mbar, comprises a cylindrical tank comprising a top, a side, and a bottom, wherein the bottom is convex, extending away from the top; a stirring shaft disposed within the cylindrical tank along an axis thereof so that it is rotatable from outside of the cylindrical tank; an impeller extending from the stirring shaft in the cylindrical tank and comprising a plurality of blades; a reactant solution inlet; a reaction solution outlet; and an externally located heat exchanger in fluid communication with the cylindrical tank via a recirculation stream and a heated stream. The reactor can be used for the polymerization of a polycarbonate oligomer.