Abstract:
An apparatus for synthesis of a polymer with separation of a gaseous substance comprises a reaction space having an essentially circular cylindrical upper section which is bounded by two circular faces and one shell face and has a longitudinal cylinder axis, and a lower section, an inlet orifice disposed in a circular face or the shell face of the upper section, a first outlet orifice disposed in a wall of the lower section, a second outlet orifice disposed in the shell face of the upper section opposite the first outlet orifice, and a removal device which is disposed so as to be rotatable about the longitudinal cylinder axis and is in contact with both circular faces and the shell face. This apparatus can especially be used for performance of a process including the feeding of an oligomer melt into a reaction space through an inlet orifice, the polymerization of the oligomer melt to give a polymer melt, the removal of the polymer melt from the reaction space through a first outlet orifice of the reaction space, and the removal of a gaseous substance from the reaction space through a second outlet orifice of the reaction space, wherein deposits on at least one inner wall of the reaction space are removed by a removal device and transported into the oligomer melt.
Abstract:
The present invention relates to the use of polyolefin copolymers A) for reducing color changes during the heating of polymer compositions which contain at least one thermoplastic polyamide B).
Abstract:
The present invention relates to a process for preparing an aliphatic or semiaromatic polyamide oligomer, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and elevated pressure and the oligomerization output is preferably subjected to an expansion.
Abstract:
The present invention relates to a process for the preparation of an aliphatic or partially aromatic polyamide, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and increased pressure, the reaction mixture is optionally subjected to a first decompression to reduce the water content, the (optionally decompressed) reaction mixture is heated within a short time to a temperature above the melting temperature of the polyamides and the heated reaction mixture is subjected to a (further) decompression to reduce the water content and to an after-polymerization.
Abstract:
The present invention relates to a process for preparing an aliphatic or semiaromatic polyamide oligomer, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and elevated pressure and the oligomerization output is preferably subjected to an expansion.
Abstract:
The present invention relates to semi-aromatic copolyamides having a high glass transition temperature and a high degree of crystallinity, to a polyamide molding compound containing said semi-aromatic copolyamide and to the use of the semi-aromatic copolyamides and of the polyamide molding compounds.
Abstract:
The invention relates to a process for continuously preparing polyamide oligomers. This comprises continuous conveying of an aqueous solution of polyamide-forming monomers from a reservoir vessel into an oligomerization reactor, heating of the aqueous solution beyond a dissolution or storage temperature, the residence time of the monomer solution in the oligomerization reactor being limited and the pressure or the partial vapor pressure of the water being adjusted such that a conversion of monomers to polyamide oligomers does not exceed a maximum value and/or the polyamide oligomers formed do not phase-separate or spontaneously crystallize in solid form, and continuous discharge of the polyamide oligomers from the oligomerization reactor. A polyamide oligomer preparable by this process can be provided continuously in a mixture with water in a process for preparing a semicrystalline or amorphous, thermoplastically processible polyamide and then postcondensed to give a polyamide. This polyamide can be used for production of moldings by means of injection molding, multicomponent injection molding, injection molding/welding, extrusion, coextrusion, blow molding or thermoforming.
Abstract:
The present invention relates to a process for the preparation of an aliphatic or partially aromatic polyamide, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and increased pressure, the reaction mixture is optionally subjected to a first decompression to reduce the water content, the (optionally decompressed) reaction mixture is heated within a short time to a temperature above the melting temperature of the polyamides and the heated reaction mixture is subjected to a (further) decompression to reduce the water content and to an after-polymerization.
Abstract:
The invention relates to a device for synthesizing a polymer accompanied by separating a gaseous substance. Said device comprises: a reactor chamber (1) having a substantially circular cylinder-shaped upper section (11), which is delimited by two circular surfaces (111, 112) and a circumferential surface (113) and has a longitudinal cylinder axis, and a lower section (12), the upper section (11) and the lower section (12) being connected to one another via the first circular surface (111); an inlet opening (2); a first outlet opening (3), which is arranged in a wall of the lower section (12); a second outlet opening (4), which is arranged in the second circular surface (112) or in the circumferential surface (113) between the inlet opening (2) and the second circular surface (112); and a removal device (51), which is arranged so as to be movable along the longitudinal cylinder axis at least between the second circular surface (112) and the inlet opening (2), and contacts the circumferential surface (113). The invention further relates to a method comprising: feeding an oligomer melt (7) into a circular cylinder-shaped first section (11) of a reaction chamber (1) through an inlet opening (2) tangentially to a circumferential surface (113) of the first section (11); polymerizing the oligomer melt (7) to form a polymer melt (8); removing the polymer melt (8) from the reaction chamber (1) through a first outlet opening (3) of the reaction chamber (1); and removing a gaseous substance (9) from the reaction chamber (1) through a second outlet opening (4) of the reaction chamber (1) above the inlet opening (2). Deposits on at least one inner wall of the first section (11) of the reaction chamber (1) above the inlet opening (2) are removed by a removal device (51).