Abstract: A method produces a polysilane by reacting at least two silane monomers and at least one alkali metal. The silane monomers have the following structural units: at least one aryl group, at least one alkyl group, at least one alkenyl group, and at least three halogen atoms. Wherein at least three of the halogen atoms are bonded to a silicon atom of one of the silane monomers, and the reaction step takes place in an ether-containing solvent, particularly preferably dioxane. The obtained polysilane has a high molecular mass and, at 100° C., a viscosity of 1,500 to 3,000 Pa·s. The polysilane is very suitable for being processed to form silicon carbide fibers and fiber composites.
Abstract: A method for producing ceramic fibers of a composition in the SiC range, starts from a spinning material that contains a polysilane-polycarbosilane copolymer solution. The spinning material is extruded through spinnerets in a dry spinning method and spun through a spinning duct into green fibers, and the green fibers are subsequently pyrolyzed. Accordingly, the polysilane-polycarbosilane solution contains between 75 wt. % and 95 wt. %, in particular between 80 and 90 wt. %, of an indifferent solvent, and the spinnerets have a capillary diameter between 20 and 70 ?m, in particular between 30 and 60 ?m, in particular between 40 and 50 ?m.
Abstract: A method for producing a polysilane includes a disproportionation reaction of a methylchlorodisilane mixture to form chlorine-containing oligosilane, a substitution reaction of the chlorine atoms contained in the oligosilane by the reaction with a primary amine and a cross-linking reaction of the oligosilanes using a chain former to form polysilanes. The obtained polysilanes are infusible and are very suitable for being spun to form green fibers and processed to form silicon carbide fibers and fiber composites. The method is characterized in that it can be carried out cost-effectively and quickly and with very high yields.
Abstract: A method for producing a polysilane includes a step of reacting (i) at least two silane monomers and (ii) at least one alkali metal. The silane monomers contain the following structural units: at least one aryl group, at least one alkyl group, at least one alkenyl group, and at least three halogen atoms. At least three of the halogen atoms are bonded to a silicon atom of one of the silane monomers.
Type:
Grant
Filed:
January 13, 2015
Date of Patent:
April 5, 2016
Assignee:
BJS Ceramics GmbH
Inventors:
Tobias Lehmann, Joahim Bill, Andreas Kienzle