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: The present invention is directed to methods for flameproofing cellulose fibres and articles containing these fibres. The method involves treatment of materials with cyanuric chloride.

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 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: 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.