Abstract: A description is given of continuous fibers based on cellulose and/or cellulose derivatives, more particularly for producing flame-retardant textiles or carbon fibers. The cellulose and/or the cellulose derivatives are in a dehydrated form in the continuous fibers. The oxygen content is 29 to 39 wt %, the limiting oxygen index LOI is 25 to 40 (according to DIN EN ISO 6941; 2004-05) and the density is 1.3 to 1.45 g/cm3 (according to DIN 65569-1; 1992-10). The continuous fibers may be produced advantageously by impregnating the starting fibers with a solution, more particularly an aqueous solution, of a specific salt which under thermal conditions releases a dehydrating acid which brings about the dehydration of cellulose and/or of cellulose derivatives in a subsequent thermal stage. The continuous fibers of the invention can be used in particular to produce advantageous carbon fibers.

Abstract: The invention relates to a prestressed concrete body, containing prestressed filament yarns based on cellulose and/or cellulose derivatives. Advantageously, said prestressed concrete body is produced in that: 1.) filament yarns based on cellulose and/or derivatives thereof are clamped into a shaping container, 2.) the clamped filament yarns are wetted with water to make them swell, 3.) a prestress of approximately 0.5 to 10.0 kg/4000 dtex is applied to the wetted filament yarns, 4.) liquid concrete is poured into the shaping container containing the prestressed filament yarns, 5.) the liquid concrete in the shaping container is cured to form precast concrete, maintaining the specified applied prestress. Useful application possibilities are opened up by the invention.

Abstract: A catalyst for the synthesis of oxazolidinones, preferable polyoxazolidinones, comprising an N-heterocyclic carbene and a Lewis acid (L). The invention is also related to a process for the production of an oxazolidinone compound, preferably a polyoxazolidinone compound, by reacting an isocyanate compound, preferably a polyisocyanate compound with an epoxide compound, preferably a polyepoxide compound, in the presence of the N-heterocyclic carbene and a Lewis acid catalyst and also to the resulting polyoxazolidinone.

Abstract: The invention relates to immobilized metal alkylidene catalysts. The catalysts are useful in olefin metathesis.

Abstract: The invention relates to immobilized metal alkylidene catalysts. The catalysts are useful in olefin metathesis.

Abstract: The present invention relates to a novel, rapid initiating mechanism for anionic, ring-opening polymerization of lactones by means of latent initiators based on N-heterocyclic carbene compounds which can be thermally activated, such as, in particular, N-heterocyclic carbene-CO2, carbene-CS2 and carbene-metal compounds (NHC). Molecular weights of 2000 to more than 20 000 g/mol and narrow polydispersities can thus be realized using the novel initiating mechanism for the polymerization of ?-caprolactone. The polymerizations may be carried out either without solvent or in solution. Compounds of this type are thermally latent and initiate a polymerization to give polylactones on heating, sometimes in high yields up to a level of quantitative conversion, while a reaction does not occur at room temperature. The polydispersity and molecular weight of the polylactone can be adjusted by selection of the initiator and the reaction conditions.

Abstract: The present invention relates to a novel, rapid initiation mechanism for polymerising (meth)acrylates using latent initiators based on N-heterocyclic carbene compounds which can be thermally activated, such as, in particular, N-heterocyclic carbene-CO2 compounds, carbene-CS2 compounds or carbene-metal compounds (NHC). Using the new initiation mechanism, molecular weights of 10 000 to over 500 000 g/mol and a narrow polydispersity can be achieved for polymerisation of MMA. The polymerisations can be carried out both without solvent and in solution.

Abstract: Metallocenes of the formula ##STR1## where M is a metal selected from the group consisting of Ti, Zr, Hf, V, Nb, Ta or an element selected from the group of the lanthanides, X.sub.1 and X.sub.2 are each an alkyl, alkoxy, aryl, aryloxy, alkenyl, arylalkyl, alkylaryl or arylalkenyl group, hydrogen or halogen and L.sub.1 and L.sub.2 are each a hydrocarbon which can form a sandwich structure with M, where at least L.sub.1 or L.sub.2 is substituted by or condensed with a ferrocene or ruthenocene radical. R.sub.1 is C, Si, Ge or Sn or the whole bridge A(R.sub.1).sub.n B is a biphenylene radical which is unsubstituted or substituted by A and/or B, A and B have the meanings of X.sub.1 and X.sub.2, n is an integer from 0 to 4.