Abstract:
The present invention relates to a process and to an apparatus for continuous living polymerization of cationically polymerizable monomers, in which at least three feedstocks are mixed in one or more mixers with microstructures and then polymerized in at least one reaction zone.
Abstract:
The invention relates to a continuous process for the preparation of amphiphilic graft polymers, wherein a vinyl ester component(B) composed of vinyl acetate and/or vinyl propionate (B1) and, if desired, a further ethylenically unsaturated monomer (B2), is polymerized in the presence of a polyalkylene oxide (A), a free radical-forming initiator (C) and, if desired, an additive(D), at a mean polymerization temperature at which the initiator (C) has a decomposition half-time of from 1to 500 min, in at least one tubular reactor segment with a feed side and an outlet side, through which the reaction mixture comprising at least a part of component (A) to (C), and if desired (D), streams. The invention further relates to an inventive amphiphilic graft polymer and the use thereof.
Abstract:
The present invention relates to a method for the continuous production of a polymer by radical polymerization, wherein at least three materials are mixed with microstructures in one or more mixers and are then polymerized in at least one reaction zone.
Abstract:
A continuous method for multi-staged drying and subsequent condensation of solid phase polyamide granulate is characterized in that 1) the pre-drying is carried out in a continuous drying apparatus operated in counter-flow or cross-flow mode with inert gas, steam or a mixture of inert gas and steam at a granulate temperature in the range of 70 to 200°C and 2) the subsequent continuous post-condensation is carried out in a separate shaft with a moving bed at a granulate temperature in the range of 120 to 210°C, wherein the shaft is operated in counter-flow mode with inert gas, steam or a mixture of inert gas and steam, the inert gas is fed at at least two points along the shaft, wherein 15 to 90% of the inert gas is fed at the base of the shaft and 10 to 85% of the inert gas is fed at the upper half below the granulate surface.
Abstract:
The invention relates to a method for producing aqueous solutions of homo or copolymers of acrylic acid by means of radical polymerization of acrylic acid and optional water-soluble, monoethylene unsaturated comonomers in an aqueous medium in the presence of at least one water-soluble initiator and at least one water-soluble regulator, wherein the polymerization is performed by means of a continuous process, and wherein low-molecular components are at least partially separated out of the aqueous polymer solution obtained after polymerization. Microstructured mixers and reactors are preferably used for the polymerization. At least one reactor and/or mixer having microstructures are preferably used for the process.
Abstract:
The invention relates to a tube bundle heat exchanger (R) for removing dissolved substances from a polymer solution (P) by degassing, having a bundle of tubes (R) which are arranged parallel to one another and vertically and are fastened at both ends in each case in one tube plate (B), and having a degassing region below the lower tube plate (B), having an insert (1) in each tube (R), which insert (1) narrows the free throughflow cross section through the tube (R), and wherein the polymer solution (P) is supplied into the tubes (R) in a single-phase liquid state, and having a casing space around the tubes (R) which is traversed by a heat carrier, wherein the degassing takes place by means of a pressure drop between the inlet pressure of the polymer solution (P) in the tube bundle heat exchanger (R) and the degassing region, characterized in that each insert (1) is designed in such a way as to generate a pressure step between the inlet pressure and the pressure in the degassing region, by means of which pressure step a predefined low residual content of dissolved substances is obtained in the degassed polymer, and an additional heat input which is necessary for this purpose takes place via the heat carrier into the single-phase liquid polymer solution (P).