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: The invention relates to a method of producing a carbon-ceramic shaped body comprising a carbon fibre-reinforced carbon matrix and a content of silicon carbide and silicon, characterised in that a carbonisable shaped body having an organic matrix based on cellulose and reinforced with carbonisable textile structures has been carbonised to form a porous shaped body and the porous carbonised shaped body is then subjected to a liquid silicisation to give the carbon-ceramic shaped body, This method is performable in an economically advantageously manner without losing the beneficial properties achievable according to the prior art.

Abstract: The present invention relates to a regenerated cellulose fiber which contains a hydrophobic substance selected from the group consisting of alkyl ketene dimers, alkenyl ketene dimers, alkyl succinic anhydrides, alkenyl succinic anhydrides, alkyl glutaric acid anhydrides, alkenyl glutaric acid anhydrides, alkyl isocyanates, alkenyl isocyanates, fatty acid anhydrides as well as mixtures thereof incorporated in the cellulose matrix.

Abstract: The invention relates to a process for producing carbon fibers from cellulosic fibers, characterized in that cellulosic fibers, which contain a sulfonic acid salt of formula (I), wherein R1 represents a hydrocarbon group and K+ represents a cation, are converted into carbon fibers.

Abstract: A method for producing films, fibers, and moldings of a polybenzazole polymer (P) by reacting at temperatures of 0 to 120° C. a mixture including (a) aromatic dicarboxylic compound(s) (I): wherein Ar1 is optionally substituted phenylene, naphthalenediyl, anthracenediyl, biphenyldiyl, diphenylmethanediyl, diphenyl ether diyl, diphenyl thio ether diyl, diphenyl sulfone diyl, benzophenonediyl, pyridinediyl, pyrimidinediyl, furandiyl, or thiophenediyl, substituents being —F, —Cl, —Br, —OR1, and —C1-C10-alkyl, R1 being —H or —C1-C10-alkyl; X1 and X2 are independently-OR2, —F, —Cl, or —Br, R2 being —H, —C1-C10-alkyl, —C1-C10-alkenyl or a repeating unit (a): wherein m is a natural number from 1 to 50, and R3 is —H, C1-C10-alkyl, or C1-C10-alkenyl; (b) aromatic diamino compound(s) of formula (IIa), (IIb), (IIc) and/or (IId); (c) at least one ionic liquid (IL), to obtain a product, processing the product at temperatures 0 to 100° C. and heating of the articles obtained at temperatures of 250 to 500° C.

Abstract: The present invention relates to a method for producing a polybenzazole polymer (P) by reacting a reaction mixture (RG) comprising at least one aromatic dicarboxylic compound of the general formula (I), at least one aromatic diamino compound of the general formula (IIa), (IIb), (IIc) and/or (IId) and also at least one ionic liquid (IL). The present invention also relates to the polybenzazole polymer (P), which is obtainable by the method according to the invention, and also to the use of the polybenzazole polymer (P), for example as fiber material.

Abstract: The invention relates to a process for producing carbon fibers from cellulosic fibers, characterized in that cellulosic fibers, which contain a sulfonic acid salt of formula (I), wherein R1 represents a hydrocarbon group and K+ represents a cation, are converted into carbon fibers.

Abstract: The invention relates to a process for the production of polymer fibers from polymers dissolved in ionic liquids by means of an air gap spinning process, characterized in that a) a spinning solution that contains an ionic liquid and a dissolved polymer is produced; b) said spinning solution is guided through an extruder before it is divided into fibers via a die; and c) the obtained fibers are guided via an air gap through a coagulation bath.

Abstract: A method of producing carbon fibers from cellulose fibers comprises bringing cellulose fibers having a water content of more than 20 parts by weight of water per 100 parts by weight of cellulose fiber into contact with a solution of additives and thereafter converting the additized cellulose fibers comprising not less than 1 part by weight of additives per 100 parts by weight of cellulose into carbon fibers.

Abstract: The present invention relates to a regenerated cellulose fiber which contains a hydrophobic substance selected from the group consisting of alkyl ketene dimers, alkenyl ketene dimers, alkyl succinic anhydrides, alkenyl succinic anhydrides, alkyl glutaric acid anhydrides, alkenyl glutaric acid anhydrides, alkyl isocyanates, alkenyl isocyanates, fatty acid anhydrides as well as mixtures thereof incorporated in the cellulose matrix.

Abstract: A process for producing porous structures from polyamide by dissolving the polyamide in an ionic liquid and precipitating or coagulating the dissolved polyamide by contacting the solution with a liquid precipitant medium. Fibers are produced from the dissolved polyamide in a wet-spinning process by precipitation in protic solvents, in particular water, a C1-4-alkanol or mixtures thereof, and subsequent freeze-drying. Foils, films or coatings are produced by blade coating the dissolved polyamide onto a substrate surface, optionally spraying with protic solvent, in particular water, a C1-4-alcohol or mixtures thereof, dipping into a precipitation or coagulation bath, freeze-drying of the resulting foil, of the film or of the coated substrate. Molded parts are prepared by extracting the dissolved polyamide with protic solvents, preferably water, a C1-4-alcohol or mixtures thereof, wherein the dissolved polymer is transformed to a solid or wax-like state by cooling and extracted after subsequent molding.

Abstract: The invention relates to a method for producing regenerated biopolymers in the form of carbohydrates, using a solvent system that contains the biopolymers dissolved therein. The solvent system is based on a melted ionic liquid and optionally a protic solvent or a mixture thereof. The biopolymers dissolved in the solvent system are precipitated in a coagulation medium, said medium comprising a protic coagulant or a mixture of protic coagulants. The method according to the invention is characterized in that the surface tension ? of the coagulant or the mixture of coagulants is 99% to 30% of the surface tension ? of water, the surface tension being measured according to ASTM D 1590-60 at a temperature of 50° C. The method according to the invention is economical and flexible and leads to advantageous products, especially in the form of staple fibers which are especially not fibrillated and have an advantageous wet to dry strength ratio.

Abstract: A process for the manufacture of a fiber or foil comprising at least one optionally functionalized polymer with a high Tg selected from the group consisting of poly(aryl ether sulfone) (PAES), poly(aryl ether ketone) (PAEK) and aromatic polyimide, comprising the steps of (aa) providing a solution comprising at least 45 wt. % of the polymer, and at least 20 wt. %, of at least one halogen-free organic solvent (S1) for the polymer, both wt % based upon the weight of the solution; (bb) pushing the solution through a nozzle; and (cc) introducing the solution into a coagulation bath comprising: (cc1) at least one liquid (L1) in which the polymer is insoluble, and optionally (cc2) at least one organic solvent (S2) for the polymer, identical to or different from the organic solvent (S1), to form a fiber or foil. A fiber or foil obtained by this process as well as to fibers or foils with specific porosity features and/or mechanical properties.

Abstract: A solution system for biopolymers in the form of carbohydrates based on a molten ionic liquid, additives optionally being contained in the solution system, is described. This solution system contains a protic solvent or a mixture of several protic solvents, and in the case where the protic solvent is solely water, this is present in the solution system in an amount of more than about 5 wt. %. Carbohydrates can be incorporated into the solution system, in particular in the form of starch, cellulose and derivatives thereof, and it can then be used for regeneration of the carbohydrates contained therein. A particularly advantageous process for the preparation of the solution system containing the carbohydrates and for the preparation of regenerated carbohydrates, in particular in the form of regenerated cellulose fibers, is moreover described. The invention accordingly also provides such spun fibers as are distinguished in that they are non-fibrillating.

Abstract: A process for the manufacture of a fiber or foil comprising at least one optionally functionalized polymer with a high Tg selected from the group consisting of poly(aryl ether sulfone) (PAES), poly(aryl ether ketone) (PAEK) and aromatic polyimide, comprising the steps of (aa) providing a solution comprising at least 45 wt. % of the polymer, and at least 20 wt. % of at least one halogen-free organic solvent (S1) for the polymer, both wt % based upon the weight of the solution; (bb) pushing the solution through a nozzle; and (cc) introducing the solution into a coagulation bath comprising: (cc1) at least one liquid (L1) in which the polymer is insoluble, and optionally (cc2) at least one organic solvent (S2) for the polymer, identical to or different from the organic solvent (S1), to form a fiber or foil. A fiber or foil obtained by this process as well as to fibers or foils with specific porosity features and/or mechanical properties.

Abstract: A process for producing porous structures from polyamide by dissolving the polyamide in an ionic liquid and precipitating or coagulating the dissolved polyamide by contacting the solution with a liquid precipitant medium. Fibers are produced from the dissolved polyamide in a wet-spinning process by precipitation in protic solvents, in particular water, a C1-4-alkanol or mixtures thereof, and subsequent freeze-drying. Foils, films or coatings are produced by blade coating the dissolved polyamide onto a substrate surface, optionally spraying with protic solvent, in particular water, a C1-4-alcohol or mixtures thereof, dipping into a precipitation or coagulation bath, freeze-drying of the resulting foil, of the film or of the coated substrate. Molded parts are prepared by extracting the dissolved polyamide with protic solvents, preferably water, a C1-4-alcohol or mixtures thereof, wherein the dissolved polymer is transformed to a solid or wax-like state by cooling and extracted after subsequent moulding.

Abstract: The invention relates to a method for producing regenerated biopolymers in the form of carbohydrates, using a solvent system that contains the biopolymers dissolved therein. The solvent system is based on a melted ionic liquid and optionally a protic solvent or a mixture thereof. The biopolymers dissolved in the solvent system are precipitated in a coagulation medium, said medium comprising a protic coagulant or a mixture of protic coagulants. The method according to the invention is characterized in that the surface tension a of the coagulant or the mixture of coagulants is 99% to 30% of the surface tension a of water, the surface tension being measured according to ASTM D 1590-60 at a temperature of 50° C. The method according to the invention is economical and flexible and leads to advantageous products, especially in the form of staple fibers which are especially not fibrillated and have an advantageous wet to dry strength ratio.

Abstract: The invention relates to a polyester based on a polycondensation product of terephthalic acid and/or terephthalic acid derivatives comprising bivalent alcohols. Said polyester is characterised in that (I) between 40 and less than 90 mol. % of ethylene glycol, propane-1,3-diol and/or butane-1,4-diol is combined with (II) between 60 and more than 10 mol. % alkane-1,2-diol, exclusively ethylene glycol, and the polyester has a melting point of between approximately 145 and 250° C. (in accordance with DIN EN ISO 53765). It has a comparatively low melting point, such that it can be retreated at the lower melting temperature. This prevents undesired secondary and decomposition reactions during the retreatment, and enables energy costs to be reduced. The inventive polyester is especially suitable for producing fibres or filaments by melt-spinning, and films, bottles and other moulded parts according to an injection moulding method. The fibres can be treated to form a high-quality nonwoven material.

Abstract: A solution system for biopolymers in the form of carbohydrates based on a molten ionic liquid, additives optionally being contained in the solution system, is described. This solution system contains a protic solvent or a mixture of several protic solvents, and in the case where the protic solvent is solely water, this is present in the solution system in an amount of more than about 5 wt. %. Carbohydrates can be incorporated into the solution system, in particular in the form of starch, cellulose and derivatives thereof, and it can then be used for regeneration of the carbohydrates contained therein. A particularly advantageous process for the preparation of the solution system containing the carbohydrates and for the preparation of regenerated carbohydrates, in particular in the form of regenerated cellulose fibers, is moreover described. The invention accordingly also provides such spun fibers as are distinguished in that they are non-fibrillating.

Abstract: The invention relates to a method for reducing the caprolactam content of polyamide 6 obtained especially by hydrolytic polymerization of epsilon-caprolactam. The method is characterized by the use of an additive that forms isocyanuric acid under the influence of heat. The additive or the isocyanuric acid produced externally under the influence of heat is added (a) to the polymerization or (b) to a melt of polyamide 6. This enables the caprolactam content of the polyamide 6 to be reduced considerably compared to that of usual commercial polyamide 6. In particular, the resulting polyamide 6 shows good characteristics for reprocessing e.g. into fiber and molding masses by melt extension.