摘要:
The present invention relates to a process for the production of polyarylene ether block copolymers comprising, in a first stage, the reaction of at least one aromatic dihydroxy compound comprising 4,4′-dihydroxybiphenyl in a molar excess and of at least one aromatic dihalogen compound, to form a polybiphenyl sulfone polymer, and then, in a second stage, the reaction of the polybiphenyl sulfone polymer with at least one aromatic dihydroxy compound and of at least one aromatic dihalogen compound.The invention further relates to the resultant polyarylene sulfone block copolymers and to the use of the polyarylene sulfone block copolymers for the production of moldings, fibers, films, or foams.
摘要:
An aromatic polyether sulfone block copolymer comprises hydrophilic segments which have sulfonic acid groups and hydrophobic segments which have no sulfonic acid groups, wherein the proportion by weight of hydrophilic segments is from 0.02 to 0.35.
摘要:
The thermoplastic molding composition comprises: a) as component A, from 0 to 97.9% by weight of one or more (methyl)styrene-acrylonitrile copolymers which do not have any units derived from maleic anhydride, and which have an intrinsic viscosity smaller than 85 ml/g, b) as component B, from 1 to 98.9% by weight of one or more (methyl)styrene-acrylonitrile copolymers which have, based on the entire component B, from 0.5 to 5% by weight of units derived from maleic anhydride, c) as component C, from 1 to 75% by weight of glass fibers, d) from 0.1 to 20% by weight of one or more flow promoters, selected from d1) as component D1, at least one highly branched or hyperbranched polycarbonate with an OH number of from 1 to 600 mg KOH/g of polycarbonate (to DIN 53240, part 2), d2) as component D2, at least one highly branched or hyperbranched polyester of AxBy type, where x is at least 1.1 and y is at least 2.1, d3) as component D3, alkyl acrylate oligomers with a weight-average molar mass in the range from 1200 to 4000 g/mol, e) as component E, from 0 to 40% by weight of further fillers, or rubbers, and/or further additives, where the total amount of components A to D and, if present, E is 100% by weight.
摘要:
A blow filter device for breathing masks and hoods, comprising a blower which is driven by a motor and at least one filter which is arranged upstream from the blower, in addition to an electronic control system for adjusting a predefined airflow volume. The invention is characterized in that the motor is an electronically commutated direct current motor (6) which is controlled with the aid of a pulse width modulation ratio as a control variable, wherein a calibrating curve is created and stored in the memory (14) of the electronic control system and is based on a plurality of different filter resistances and a respectively corresponding pulse-width modulation ratio (PWM) and the respective motor speed (n) for a specific volume of air. The direct current motor can be controlled in the hood mode according to the speed (n) measured in relation to the respective filter resistance after activation with the aid of the associated pulse-width modulation ratio read from the calibrating curve and can be controlled in the mask mode independently of the respective filter resistance with a respective specific constant pulse-width modulation ratio (PWM) for the associated mask type, wherein the electronic control system (5) is associated with an identifying means (19,20) which is used to recognize the associated head part and to adjust the operational mode concerned.
摘要:
Semiconductor wafers of silicon are produced by pulling a single crystal growing on a phase boundary from a melt contained in a crucible and cutting of semiconductor wafers therefrom, wherein during pulling of the single crystal, heat is delivered to a center of the phase boundary and a radial profile of a ratio V/G from the center to an edge of the phase boundary is controlled, G being the temperature gradient perpendicular to the phase boundary and V being the pull rate. The radial profile of the ratio V/G is controlled so that the effect of thermomechanical stress in the single crystal adjoining the phase boundary, is compensated with respect to creation of intrinsic point defects. The invention also relates to defect-free semiconductor wafers of silicon, which can be produced economically by this method.
摘要:
The present invention relates to thermoplastic molding compositions composed of the following components: (A) at least one polyarylene ether (A1) having an average of at most 0.1 phenolic end groups per polymer chain, and at least one polyarylene ether (A2) having an average of at least 1.5 phenolic end groups per polymer chain, (B) at least one fibrous or particulate filler, and (C) optionally further additives and/or processing aids. The present invention further relates to a process for producing the thermoplastic molding compositions of the invention, the use of these for producing moldings, fibers, foams, or films, and to the resultant moldings, fibers, foams, and films.
摘要:
An electrochemical gas sensor includes an electrolyte including at least one ionic liquid which includes an additive portion including at least one organic additive, at least one organometallic additive or at least one inorganic additive.
摘要:
The present invention relates to thermoplastic molding compositions comprising the following components: (A) at least one polyarylene ether (A1) having an average of at most 0.1 phenolic end group per polymer chain and at least one polyarylene ether (A2) having an average of at least 1.5 phenolic end groups per polymer chain, (B) at least one polyarylene sulfide, (C) at least one functionalized polyarylene ether comprising carboxy groups, (D) at least one fibrous or particulate filler, and (E) optionally further additives and/or processing aids. The present invention further relates to a process for producing the thermoplastic molding compositions of the invention, to the use of these for producing moldings, fibers, foams, or films, and to the resultant moldings, fibers, foams, and films.
摘要:
Silicon single crystals are pulled from a melt in a crucible, the single crystal surrounded by a heat shield, the lower end of which is a distance h from the melt surface, wherein gas flows downward between the single crystal and the heat shield, outward between the lower end of the heat shield and the melt, and then upward in the region outside the heat shield. The internal diameter of the heat shield at its lower end is 55 mm or more than the diameter of the single crystal, and the radial width of the heat shield at its lower end is not more than 20% of the diameter of the single crystal. Highly doped single crystals pulled accordingly have a void concentration ≦50 m−3.
摘要:
Sheet-like moldings or foils with anisotropic coefficients of thermal expansion are produced from extrudable thermoplastic polymer molding compositions by filling the thermoplastic polymer molding compositions with lamellar phyllosilicates whose diameter is in the range from 10 to 1000 nm and whose aspect ratio is in the range from 1:5 to 1:10 000 and extruding the filled thermoplastic polymer molding compositions, and then monoaxially or biaxially orienting the extrudate to give sheet-like moldings or foils.