Abstract: The present invention relates to cross-linked polysiloxanes containing organic bridging groups Ver, a method for preparing said cross-linked polysiloxanes, blends containing said polysiloxanes and fillers, a method for biobased degradation of said polysiloxanes, the use of the organic bridging groups Ver, the precursors of which contain non-terminal functional groups and/or heteroatoms, in the cross-linked polysiloxanes for the biobased degradation of the cross-linked polysiloxanes by means of a biobased agent, and the use of the cross-linked polysiloxanes and the blend for industrial applications.

Abstract: A heat pipe having a working chamber having an evaporator region operatively connected to a heat source, and a condenser region operatively connected to a heat sink. A working fluid is provided in the working chamber, and heat is transferred from the heat source to the heat sink by the working fluid in a first state of operation. The heat pipe is a switchable and/or programmable thermal diode or a switchable and/or programmable heat switch, at least one activatable functional material is provided, which is arranged and configured to keep the evaporator region free of the working fluid and/or to prevent the working fluid from evaporating in a second state of operation, in order to reduce and/or hinder heat transfer and/or to alter the preferential direction of heat conduction. A system and method for switching and/or programming heat transfer in a heat pipe are also provided.

Abstract: The invention relates to a method for producing a polysilane-polycarbosilane copolymer solution. Said method comprises the preparation of a polysilane, obtained by the disproportionation of a methylchlorodisilane or a mixture of methylchlorodisilanes of formula Si2MenC16-n with a Lewis base as the catalyst, a subsequent thermal cross-linking of the polysilane to form an infusible polysilane-polycarbosilane copolymer that is soluble in inert solvents, in addition to the production of said solution by the dissolution of the polysilane-polycarbosilane copolymer in an inert solvent. The invention also relates to a method for producing oxygen-depleted ceramic fibers and other molded bodies with a composition similar to that of SiC. Said method comprises the spinning of the solution to obtain green fibers according to the dry spinning method and the pyrolysis of the dried green fibers in an inert gas atmosphere or a reductive atmosphere.

Abstract: The present invention pertains to a process for producing unmeltable polysilane-polycarbosilane copolymers which are soluble in inert solvents, comprising the steps providing the product of a disproportionation of a methylchlorodisilane or a mixture of several methylchlorodisilanes of the composition Si2MenCl6-n, wherein n=1?4, wherein the disproportionation was carried out with a Lewis base as a catalyst, wherein this product is a chlorine-containing, crude polysilane/oligosilane containing hydrocarbon groups, and thermally postcrosslinking the crude polysilane/oligosilane to a polysilane-polycarbosilane copolymer, characterized in that the chlorine content of the polysilane-polycarbosilane copolymer is lowered by reacting the crude polysilane/oligosilane with a substitution agent, by which chlorine bound therein is replaced with a chlorine-free substituent. Green fibers and low-oxygen/oxygen-free ceramic fibers with a very low chlorine content can be produced using this process.

Abstract: The invention relates to a method for producing a polysilane-polycarbosilane copolymer solution from which a ceramic material having a ratio of silicon to carbon in the range of 0.8:1.0 to 1.1:1.0 can be obtained after removal of the solvent and pyrolysis, comprising the following steps: generating a chloric raw polysilane/oligosilane containing hydrocarbon groups by means of disproportioning a methylchlorodisilane or a mixture of a plurality of methylchlorodisilanes of the composition Si2MenCl6-n, where n=1-4, wherein the disproportioning takes place by means of a Lewis base as a catalyst, thermally post-cross-linking the raw polysilane/oligosilane into a non-melting polysilane-polycarbosilane copolymer that is soluble in a neutral solvent, and producing said solution by means of dissolving the polysilane-polycarbosilane in a neutral solvent.

Abstract: The present invention pertains to a process for producing unmeltable polysilane-polycarbosilane copolymers which are soluble in inert solvents, comprising the steps providing the product of a disproportionation of a methylchlorodisilane or a mixture of several methylchlorodisilanes of the composition Si2MenCl6-n, wherein n=1-4, wherein the disproportionation was carried out with a Lewis base as a catalyst, wherein this product is a chlorine-containing, crude polysilane/oligosilane containing hydrocarbon groups, and thermally postcrosslinking the crude polysilane/oligosilane to a polysilane-polycarbosilane copolymer, characterized in that the chlorine content of the polysilane-polycarbosilane copolymer is lowered by reacting the crude polysilane/oligosilane with a substitution agent, by which chlorine bound therein is replaced with a chlorine-free substituent. Green fibers and low-oxygen/oxygen-free ceramic fibers with a very low chlorine content can be produced using this process.

Abstract: The present invention relates to novel alkylhalosilylaminoboranes, in particular alkylchlorosilylaminoboranes, which make it possible to adjust the viscosity of polyborosilazane compounds by varying the number of reactive centers, to novel borosilazane compounds, to novel oligoborosilazane or polyborosilazane compounds which have the structural feature R1—Si—NH—B—R2, where R1 or R2 or both is/are a hydrocarbon radical having from 1 to 20 carbon atoms, in particular an alkyl, phenyl or vinyl group, to silicon borocarbonitride ceramic powder, to ceramic material based on SiC, SiN and BN and to processes for producing each of these and to the use of the polyborosilazanes and the ceramic materials.