Centre National De La Recherche Scientifique

Université Claude Bernard Lyon I

Ahlstrom Corporation

Commissariat a L'energie Atomique

Laboratoire Tetra Medical

Alain Domard

Laurent David

Florence Dupasquier

Eliane Espuche

Yves Berton

Alexandra Montembault

Noel Cartier

Mylène Desorme

Noël Cartier

Séverine Despond

Severine Despond

Veronique Federici

Estelle Piron

Ricio Rivas

Christophe Viton

The invention relates to a method for producing an elongate polysaccharide element, in particular a chitosan thread, comprising an operation of extruding an extrusible solution of said polysaccharide through an extrusion die and an operation of coagulating the extruded solution. The extrusible solution is a hydroalcoholic solution containing an alcohol that does not form an azeotrope with water and which has a boiling point of more than 150&#xb0; C. at atmospheric pressure. The coagulation operation includes a step of evaporating the water, preferably over the alcohol, producing a gelled extruded elongate element in the form of a mainly alcoholic gel, in particular by subjecting the extruded solution to a hot air flow. At least one operation of eliminating the alcohol contained in said gel makes it possible to obtain the elongate polysaccharide element. The chitosan thread has a crystalline structure corresponding to the anhydrous allomorph and a rupture stress of at least 150 MPa after being immersed in demineralized water for fifteen hours. The apparatus (1) for the wet extrusion of polysaccharide thread () includes an extruder () with at least one extrusion die (), an evaporation enclosure () placed immediately after the output () of the extrusion die () and supplied with a hot air flow, a neutralization unit (), a washing unit (), a drying unit () and a winding unit ().

Chitosan yarn having a crystal structure corresponding to the anhydrous allomorph and a tensile strength, after immersion in demineralized water for fifteen hours, of at least 150 MPA

The present invention relates to a method for preparing by wet spinning a continuous filament based on hyaluronic acid in free acid form, notably soluble in water. The preparation method according to the invention comprises the following steps: a) preparing a spinnable aqueous solution of hyaluronic acid or of a hyaluronic acid salt, preferably a sodium hyaluronate solution; b) extruding said solution to an extrusion die; c) forming the filament by passing the extruded solution into a bath of acetic acid, concentrated to more than 80%, drawing and drying. The invention also relates to a filament based on hyaluronic acid in free acid form, said filament having swelling properties in water and physiological liquids and moreover being solubilizable in water under certain conditions.

Filament based on hyaluronic acid in the form of free acid and method for obtaining it

Support based on organic and/or inorganic fibres covered at least on one of the faces thereof with a chitosan-based layer, characterized in that the layer is obtained by depositing a chitosan-based aqueous solution, the average molar mass of which has a mass less then 130 000 g/mol, the concentration of which is between 6 and 30% by weight and the viscosity of which is between 100 and 3000 cps.

Support covered with a chitosan-based coating and method for the production thereof

The invention concerns the use of a material based on organic and/or inorganic fibres and chitosan for fixing metal ions contained in an effluent. The invention is characterised in that chitosan represents between 0.01 and 20% by dry weight of fibres and its degree of deacetylation is higher than 90%.

Use of material based on organic and/or inorganic fibres and chitosan for fixing metal ions

The invention relates to a method for separating metals present in a solution using chitosane. According to the present invention, chitosane in modified physical form is used which allows faster, more extensive fixation of the metals present in a solution. This purpose is achieved using a method in which the chitosane used is a lyophilizate of chitosane, in particular a lyophilizate of chitosane salt. ##STR1##

Method of separating at least one metal present in a solution by

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Lyons, France

Alain Domard