Method for obtaining an elongate polysaccharide element, in particular a chitosan thread

Patent metadata

Field	Value
Publication number	US-9567406-B2
Application number	US-201113582537-A
Country	US
Kind code	B2
Filing date	Mar 4, 2011
Priority date	Mar 5, 2010
Publication date	Feb 14, 2017
Grant date	Feb 14, 2017

Abstract

A method for obtaining an elongate polysaccharide element, in particular a chitosan thread, includes extruding a hydroalcoholic extrusible solution containing a polyalcohol of said polysaccharide through an extrusion die, coagulating the extruded solution by neutralization, and at least one operation of removing the polyalcohol. The ratio of water to polyalcohol in the extrusible solution is determined such as to obtain in the elongate element a polysaccharide with the crystalline structure thereof mainly in the form of an anhydrous allomorph. Since the polysaccharide used to prepare the extrusible solution has a weight-average molar mass Mw 0 , the polysaccharide in the elongate element obtained preferably has a weight-average molar mass Mw 1 comprised between Mw 0 and 0.7 Mw 0 . Since the purpose is to obtain a chitosan thread, the latter has properties of mechanical strength and flexibility that allow the thread to be tied into overhand knots and to be woven without breaking.

First claim

We claim:

1. A chitosan yarn characterized in that it comprises a fraction of the anhydrous allomorph of chitosan of greater than or equal to 40%, corresponding to the crystalline structure.

2. The chitosan yarn as claimed in claim 1 , characterized in that it has mechanical strength and flexibility properties that enable it to be subjected, without breaking, to the formation of an overhand knot upon itself.

3. The chitosan yarn as claimed in claim 1 , characterized in that the weight-average molar mass Mw1 of the chitosan is greater than 350 000 g/mol.

4. A textile material comprising chitosan yarns, as claimed in claim 1 , alone or assembled with other yarns.

5. The chitosan yarn as claimed in claim 1 , characterized in that it comprises a fraction of the anhydrous allomorph of chitosan of greater than or equal to 50%, corresponding to the crystalline structure.

6. The textile material of claim 4 , characterized in that it is a knit fabric.

Assignees

• David Laurent
• Montembault Alexandra
• Desorme Mylène
• Laboratoire Tetra Medical
• Centre Nat Rech Scient
• Univ Claude Bernard Lyon

Inventors

• David Laurent
• Montembault Alexandra
• Desorme Mylène

Classifications

• B32B27/02

  in the form of fibres or filaments {(not used)} · CPC title

• Y10T428/2975

  Tubular or cellular · CPC title

• D01D5/06 Primary

  Wet spinning methods {(D01D5/0046 takes precedence)} · CPC title

• D01F9/04

  of alginates · CPC title

• C08B37/0024 Primary

  beta-D-Glucans; (beta-1,3)-D-Glucans, e.g. paramylon, coriolan, sclerotan, pachyman, callose, scleroglucan, schizophyllan, laminaran, lentinan or curdlan; (beta-1,6)-D-Glucans, e.g. pustulan; (beta-1,4)-D-Glucans; (beta-1,3)(beta-1,4)-D-Glucans, e.g. lichenan; Derivatives thereof · CPC title