Abstract: A method for the electrochemical preparation of alkanedicarboxylic acids involves a ring-opening oxidation with a doped Ni(O)OH foam electrode in an aqueous alkaline solution.

Abstract: A polymer composition can be used for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polymer has open mesopores and the cumulative pore volume distribution of the mesopores, measured to DIN 66134, is at least 0.01 cm3/g.

Abstract: An improved process can be used for the acid hydrolysis of polylaurolactam with sulfuric acid. An especially suitable starting material is polylaurolactam which is intended for recycling and which is characterized by a low laurolactam content.

Abstract: A method for the electrochemical preparation of alkanedicarboxylic acids involves a ring-opening oxidation with a doped Ni(O)OH foam electrode in an aqueous alkaline solution.

Abstract: A moulding composition contains polyetheramide (PEA) based on a subunit 1, made of at least one linear aliphatic diamine having 15 C atoms and at least one linear aliphatic or aromatic dicarboxylic acid having 6 to 14 C atoms. Furthermore, the PEA also contains a subunit 2, made of at least one polyether diamine having at least 2.3 C-5 atoms per ether oxygen and NH2 groups at the chain ends. The moulding composition contains a maximum of 2.5% by weight of a rubber containing functional groups. The number of C atoms of at least one component of subunit 1 selected from diamine and dicarboxylic acid is at least 13, and the average molar mass number of subunit 2 is between 200 to 900 g/mol. A moulded object can be created from the moulding compound. The object can be a moulded part, a film, a bristle, a fiber, or a foam.

Abstract: Polyamides are claimed that comprise at least 10% by weight of at least one cyclic terpenoid substructure. The substructure is preferably derived from a monoterpene. A method for preparing the polyamides and for producing the moulding compounds is also described. The moulding compounds comprise 10% to 90% by weight of these polyamides.

Abstract: A polymer composition can be used for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polymer has open mesopores and the cumulative pore volume distribution of the mesopores, measured to DIN 66134, is at least 0.01 cm3/g.

Abstract: A molding compound contains polyether block amide (PEBA) based on a subunit 1 made of at least one linear aliphatic diamine having 5 to 15 C atoms and at least one linear aliphatic or aromatic dicarboxylic acid having 6 to 16 C atoms. The PEBA also contains a subunit 2 made of at least one polyether diol having at least 3 C atoms per ether oxygen and primary OH groups at the chain ends. The sum of the C atoms of diamine and dicarboxylic acid is odd and is 19 or 21, and the number-average molar mass of the subunit 2 is 200 to 900 g/mol. A molded object can be created from the molding compound, which can be a molded part, a film, a bristle, a fiber, or a foam.

Abstract: A polyamide powder for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polyamide powder has a solution viscosity to ISO 307 of 1.8 to 2 and a rise in the solution viscosity of 0% to 25% when it is subjected to a temperature 20° C. below its melting temperature under air for 20 hours.

Abstract: A polymer composition can be used in selective absorbing sintering, SAS, or selective inhibition sintering, SIS, methods. The polymer of the polymer composition has open mesopores, where a cumulative pore volume distribution of the mesopores, measured according to DIN 66134, is at least 0.01 cm3/g.

Abstract: The present invention relates to a moulding compound which contains at least 50 wt. % of a semicrystalline poly amide component and the moulding compound contains a filler which imparts conductivity to the moulding compound, wherein the moulding compound does not have a crystallite melting point (Tm) below 50° C. and the polyamide component contains components A and B, A) PA homopolymer of the type PA X.Y or PAZ, where X is a diamine radical (DA), Y is a dicarboxyl radical (DC), and Z is an alpha-omega amino acid radical; B) PA copolymer of the type PA X?.Y?, where X is a diamine radical (DA?) and Y? is a dicarboxyl radical (DC?); wherein a portion of the diamine radical (DA?) is replaced by a polyether having at least two amino termini or at least two hydroxy termini; wherein the proportion of polyether in the sum of components A and Bis between 0.5 and 15 wt. % and wherein the proportion of filler is 2.5 to 6 wt. % based on the total mass of the poly amide component and the filler.

Abstract: A polyamide powder for selective absorbing sintering, SAS, or selective inhibition sintering, SIS. The polyamide powder has a solution viscosity to ISO 307 of 1.8 to 2 and a rise in the solution viscosity of 0% to 25% when it is subjected to a temperature 20° C. below its melting temperature under air for 20 hours.

Abstract: A moulding material contains to an extent of at least 50 wt % of the combination of the following constituents a) 80 to 97 parts by mass of a polyamide component containing a1) 70 to 100 parts by wt of PA PACMX (wherein X=8 to 18), and a2) 30 to 0 parts by wt of a linear aliphatic polyamide having on average 8 to 12 carbon atoms in the monomer units, wherein the parts by wt sum to 100, and b) 20 to 3 parts by mass of a core-shell modifier which contains the following: b1) a core which contains 60 to 100 wt % of butadiene units and 0 to 40 wt % of styrene units, wherein the core makes up 60 to 95 wt % of the core-shell modifier; and b2) a shell which contains 80 to 100 wt % of methyl methacrylate units and 0 to 20 wt % of modifying monomer units, wherein the shell makes up 5 to 40 wt % of the core-shell modifier, wherein the parts by mass of a) and b) sum to 100.

Abstract: Composite particles comprising core particles completely or partially coated with a precipitated polymer, where the d50 median diameter of the core particles is from 3 to 100 ?m and wherein the glass core particle material is at least one selected from the group consisting of a solid glass bead, a hollow glass bead, a porous glass bead, and a foamed glass particle. A method to prepare the particles includes dissolution of a polymer in a solvent and precipitation of the polymer in the presence of a suspension of the core glass particles. Further provided is a layer by layer moulding process employing the composite particles and mouldings obtained therefrom.

Abstract: Composite particles comprising core particles completely or partially coated with a precipitated polymer, where the d50 median diameter of the core particles is 1 ?m or greater and the ratio of the d50 median diameter of the composite particles to the d50 median diameter of the core particles is 1.15 or greater, are provided. A method to prepare the particles includes dissolution of a polymer in a solvent and reprecipitation of the polymer in the presence of a suspension of the core particles. Further provided is a layer by layer moulding process employing the composite particles and mouldings obtained therefrom.

Abstract: The invention relates to a polymer powder for use in a layer-by-layer method in which areas of each powder layer are selectively fused by introducing electromagnetic energy. Said polymer powder contains: at least one AB-type polyamide produced by polymerizing lactams comprising 10 to 12 carbon atoms in the monomer unit or polycondensing the corresponding ?-amino carboxylic acids comprising 10 to 12 carbon atoms in the monomer unit and at least one AABB-type polyamide produced by polycondensing diamines and dicarboxylic acids, each of which comprises 10 to 14 carbon atoms in the monomer units, the AB-type polyamide containing up to 20 mole % of the AABB comonomer units and the AABB-type polyamide containing up to 20 mole % of the AB monomer units.

Abstract: Disclosed herein is a polymer powder containing a polyamide of AB type, produced by polymerizing at least one lactam having from 10 to 12 carbon atoms in a monomer unit or by polycondensing at least one corresponding ?-aminocarboxylic acid having from 10 to 12 carbon atoms in a monomer unit, and a polyamide of AABB type, produced by polycondensing at least one diamine and at least one dicarboxylic acid having respectively from 10 to 14 carbon atoms in monomer units. The polyamide of the AB type and the polyamide of the AABB type are prepared separately and then coprecipitated to form the polymer powder, and the polymer powder is a physical mixture of the polyamide of the AB type and the polyamide of the AABB type. Also disclosed herein is a method for producing the polymer powder.

Abstract: Polymers can be prepared from monomers comprising laurolactam, by a process including a. Beckmann rearrangement of cyclododecanone oxime to give laurolactam in the presence of a Beckmann rearrangement catalyst, b. removal of impurities from the laurolactam to obtain purified laurolactam, and c. polymerization of monomers comprising purified laurolactam. For avoidance of discolouration or yellowing under ageing conditions, prior to the polymerization, polycyclic substances containing 24 carbon atoms and at least one heteroatom selected from oxygen and nitrogen and having a molar mass between 300 and 380 g/mol are limited to 500 ppm, based on laurolactam.

Abstract: A polymer composition can be used in selective absorbing sintering, SAS, or selective inhibition sintering, SIS, methods. The polymer of the polymer composition has open mesopores, where a cumulative pore volume distribution of the mesopores, measured according to DIN 66134, is at least 0.01 cm3/g.

Abstract: The present invention relates to a process for the bonding of material for the production of three-dimensional objects by selective heating via a laser of wavelength from 100 to 3000 nm. The beam spot may be a focused or unfocused beam spot, or may indeed be spread, as is the case with the diode laser, where the bars may have a stacked arrangement. The selectivity of the melting process is achieved via the application of an absorber to certain subregions of a layer composed of a pulverulent substrate, and then heating of the absorber by laser radiation of wavelength from 100 to 3000 nm. The heated absorber transfers the energy present therein to its surrounding pulverulent substrate, which is melted thereby and, after cooling, has firm cohesive bonding.