Abstract: Compounds of the general formula (4) are prepared by polymerization of oxasilacycles in the presence of an acid catalyst.

Abstract: Oxasilacycles are prepared by the intramolecular condensation of silanes bearing Si-bonded hydrogen and ethylenically unsaturated radicals in the presence of a triorganoborane, aminoborane complex, or phosphine-borane complex as a hydrosilylation catalyst. Spirocyclic oxasilacycles, and alkoxy-substituted oxaspirocycles with quaternary substitution of a C atom adjacent to oxygen may be prepared.

Abstract: The invention relates to a covalently cross-linked, asymmetrically porous membranes (M) made of thermoplastic silicone elastomers; a method for producing the covalently cross-linked, asymmetrically porous membranes (M), in which, in a first step, a solution of a silicone composition SZ, which contains thermoplastic silicone elastomer S1 with alkenyl groups and contains cross-linker V, and a solvent L is produced, in a second step, the solution is brought into a mold, in a third step, the solution brought into a mold is brought into contact with a precipitation medium F, wherein a covalently non-cross-linked membrane is formed. In a fourth step, the solvent L and the precipitation medium F are removed from the non-cross-linked membrane and, in a fifth step, the membrane is subjected to a cross-linking, wherein the covalently cross-linked membrane M is formed; the membranes (M) produced according to the method; and to the use of the membranes (M) for the separation of material mixtures or for coating.

Abstract: The invention relates to a method for producing thin, porous membranes made of a thermoplastic silicone compound S, in which, in a first step, a solution or suspension of a silicone composition SZ, which contains the thermoplastic silicone elastomer S1 with alkenyl groups—and contains crosslinker V, is formed in a mixture of solvent L1 and solvent L2, in a second step, the solution or suspension is brought into a mold, in a third step, solvent L1 is removed from the solution or suspension until the solubility of the silicone composition SZ in the mixture of solvent L1 and solvent L2 falls below a threshold, wherein a phase A, which is rich in the silicone composition SZ,—and a phase B, which is poor in silicone composition SZ, are formed and thus the structural formation is carried out by phase A. In a fourth step, the solvent L2 and residues of solvent L1 are removed and the silicone composition SZ is subjected to a cross-linking, wherein the silicone compound S is formed.

Abstract: The invention relates to a method for producing thin porous membranes made of cross-linkable silicone compositions (S), according to which method an emulsion is formed from the silicone compositions (S) using a pore forming agent (P) in the presence of an emulsifier (E) and optionally solvent (L) in a first step, the emulsion is given a form and the solvent (L), if present, is allowed to evaporate in a second step, the emulsion is cross-linked in a third step, and the pore forming agent (P) is removed from the cross-linked membrane in a fourth step. The invention further relates to membranes that can be produced according to the method and to the use thereof for separating mixtures, in adhesive plasters, as a water-repellent and breathable layer in textiles or as packaging materials.

Abstract: Oxasilacycles are prepared by the intramolecular condensation of silanes bearing Si-bonded hydrogen and ethylenically unsaturated radicals in the presence of a triorganoborane, aminoborane complex, or phosphine-borane complex as a hydrosilylation catalyst. Spirocyclic oxasilacycles, and alkoxy-substituted oxaspirocycles with quaternary substitution of a C atom adjacent to oxygen may be prepared.

Abstract: Compounds of the general formula (4) are prepared by polymerization of oxasilacycles in the presence of an acid catalyst.