摘要:
The invention relates to a new, particularly economic process for preparing pulverulent polysaccharide derivatives, in particular cellulose derivatives, having a thermal flocculation point; the process comprises soaking or dissolving the polysaccharide derivative in a solvent or mixed solvent, dividing/comminuting the soaked or dissolved polysaccharide derivative by thermal and/or mechanical liquid separation and an optional drying step.
摘要:
Finely divided polysacharide derivatives are described. The finely divided polysacharide derivatives are prepared by a process comprising: a) forming an aqueous composition comprising a polysaccharide derivative and water, in which the polysaccharide derivative is soaked or dissolved; b) converting the polysaccharide derivative of the aqueous composition into finely divided solid particles by, (i) contacting the aqueous composition with superheated water vapor in a dryer-pulverizer; or (ii) causing the polysaccharide derivative of the aqueous composition to flocculate; and c) optionally drying the finely divided solid particles of step b). The primary structures of the polysaccharide starting material are largely removed, and the product has a shape factor of less than 5 and greater than or equal to 1.
摘要:
A method for producing and/or processing polymer/carbon nanotube mixtures in powder form comprises the step of grinding a mixture comprising carbon nanotubes and polymer particles. The grinding is carried out in the presence of from ≧0 weight-% to ≦15 weight-%, expressed in terms of the total weight of the mixture, of a liquid phase which does not dissolve the polymer particles and at a temperature below the melting point of the powder particles. The energy input during the grinding is preferably low. A preferred polymer is PVDF. The invention furthermore relates to polymer/carbon nanotube mixtures which can be obtained by a method according to the invention, and to the use of such polymer/carbon nanotube mixtures for the production of electrodes.
摘要:
The present invention relates to biocidal and more particularly algicidal substances comprising one or more polymers which in turn comprise one or more biocides such as more particularly algicides, where at least one polymer has structural elements which derive from acrylonitrile. The invention further relates to biocidal compositions comprising aforesaid biocidal substances in particulate form, to a process for preparing the biocidal substances and the biocidal compositions and to the use of the biocidal compositions for protecting technical materials.
摘要:
In the process for the continuous collection of pulverulent or dusty samples from a particle-laden stream, a sample stream is drawn off from a particle-laden main stream in a pneumatic conveying line 17 and passed via a collection line 9 to a particle size measurement device 10. In order to reduce spin, the main stream in the conveying line 17 is passed through a venturi-like cross-sectional constriction 3, 4, 5, the cross-sectional area of which is 10 to 60% of the free cross-sectional area of the conveying line 17. Samples are then collected downstream from the cross-sectional constriction through one or more probe tubes 7, wherein a partial stream is collected from the main stream parallel to the direction of flow thereof. In conjunction with a jet mill 14, into which the product to be ground and the propellant air are continuously introduced, the particle size distribution measured in the continuously collected sample stream may be used as a control parameter in order to adjust a parameter which determines particle size distribution of the jet mill 14 in such a manner that the particle size distribution in the product stream remains constant.
摘要:
The invention relates to a novel process for producing carbon materials which are modified at least on their surface with pyridinic, pyrrolic and/or quaternary nitrogen groups starting out from carbon nanotubes.
摘要:
For the metered feed of coarse granular material into an air jet mill an injector 3 operated by propellent air is used, the coarse material being fed continuously to a closed injector hopper 6 provided on the injector 3. In the injector hopper 6, the pressure is measured at a product-free point and, by resetting the propellent air mass flow at the injector 3 is held constant at a preselected setpoint partial vacuum value. Said setpoint value is preferably set so low that at said pressure there is only just no return flow from the injector 3 into the injector hopper 6. The apparatus for effecting said method comprises a control loop having a pressure sensor 16 for measuring the flow in the closed injector hopper 6, a motor-adjustable valve 4, 5 as an actuator for varying the supplied propellent air mass flow and a loop controller, which compares the actual pressure value with a preselected setpoint value and supplies a control signal for operating the actuator 4, 5.