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EP-4741570-A2 - FUNCTIONALIZATION AND WET STRENGTHENING OF CELLULOSIC MATERIAL BY OXIDIZED POLYSACCHARIDE

EP4741570A2EP 4741570 A2EP4741570 A2EP 4741570A2EP-4741570-A2

Abstract

The invention relates to compounds, particularly those based on polysaccharides, that adsorb onto a cellulosic material. The present invention relates in particular to the application of such compounds as reinforcing agents for cellulosic materials, in both wet and dry states. The invention relates to compounds comprising an association of at least one polysaccharide adsorbed on a cellulosic material, said polysaccharide comprising at least two different monosaccharide units, forming first and second monosaccharide units, said second monosaccharide units being branched on a chain comprising at least said first monosaccharide units, at least some of the second monosaccharide units being non-cyclic and bearing aldehyde functions, said aldehyde functions possibly forming hemiacetal functions with hydroxy functions of the cellulosic material.

Inventors

  • GAFFIOT, Lauric
  • HEUX, LAURENT

Assignees

  • Centre National de la Recherche Scientifique

Dates

Publication Date
20260513
Application Date
20190905

Claims (15)

  1. Compound comprising an association of at least one polysaccharide adsorbed on a cellulosic material, said polysaccharide comprising at least two different monosaccharide units, forming first and second monosaccharide units, said second monosaccharide units being branched on a chain comprising at least said first monosaccharide units, at least some of the second monosaccharide units being non-cyclic and bearing aldehyde functions, said aldehyde functions possibly forming hemiacetal functions with hydroxy functions of the cellulosic material, said polysaccharide being further covalently linked by one or more reactive molecules, reacting with aldehyde functions of the polysaccharide.
  2. Compound according to claim 1, characterized in that the polysaccharide comprises a chain with 1-4 glucan linkages, and preferably β(1→4) glucan linkages.
  3. Compound according to claim 1 or 2, characterized in that the adsorbed polysaccharide comprises a glucan chain, a mannan chain and/or a xylan chain.
  4. Compound according to any one of claims 1 to 3, characterized in that the non-cyclic branched monosaccharides are xyloses, galactoses, fucoses and/or arabinoses, preferably α(1→6) xylose branches, where the non-cyclic branched monosaccharides are oxidized xyloses.
  5. Compound according to any one of claims 1 to 4, characterized in that the adsorbed polysaccharide is selected from the group consisting of a xyloglucan, a glucomannan, a mannan and a galactomannan.
  6. Compound according to any one of claims 1 to 5, characterized in that the adsorbed polysaccharide is selected from the group consisting of tamarind seed xyloglucan (TXG), pea xyloglucan, low galactose galactomannan, guar gum, tara gum, cassia gum, locust bean gum and any mixture thereof.
  7. Compound according to any one of claims 1 to 6, characterized in that the adsorbed polysaccharide is a xyloglucan.
  8. Compound according to any one of claims 1 to 7, characterized in that the polysaccharide is oxidized by a periodate, and preferably sodium metaperiodate, and preferably in that the polysaccharide has a percentage of oxidation greater than 0% and less than or equal to 50%, and preferably less than or equal to 40%, and preferably less than or equal to 30%, expressed as the number of oxidized saccharide units out of the total number of saccharidic units.
  9. Compound according to any one of claims 1 to 8, characterized in that the polysaccharide is covalently linked to the cellulosic material by hemiacetal functions between aldehyde functions of branched monosaccharides and hydroxy functions of the cellulosic material.
  10. Compound according to any one of claims 1 to 9, characterized in that the reactive molecules are selected from the group comprising amines, polyamines, hydroxylamines, imines, hydrazide and any combination thereof.
  11. Method for covalently linking a cellulosic material to a polysaccharide, said method comprising the adsorption of a polysaccharide onto a cellulosic material, preferably the adsorption is carried out with the cellulosic material in aqueous media, to form a compound according to any one of claims 1 to 10 and the reaction of aldehyde functions of the polysaccharide with hydroxy functions of the cellulosic material to form hemiacetal functions, and said polysaccharide is covalently linked to the cellulosic substrate and made to react with one or more reactive molecules, reacting with aldehyde functions of the polysaccharide.
  12. Method according to claim 11, characterized in that the reactive molecules are selected from the group comprising amines, polyamines, hydroxylamines, imines, hydrazide and any of their combinations.
  13. Method according to claim 11 or 12, characterized in that it comprises, prior to the adsorption of the polysaccharide onto the cellulosic material, an oxidation step of a precursor polysaccharide of the adsorbable polysaccharide onto the cellulosic material, the oxidation step can be controlled to oxidize only the branches of the polysaccharide.
  14. Method according to any one of claims 11 to 13, characterized in that the compound according to any one of claims 1 to 10 is shaped and dried into papers, fibers, non-wovens, other.
  15. Use of one or more reactive molecules reacting with aldehyde functions of the compound as defined according to any one of claims 1 to 10, to impart a new functionality to the compound, for example antiseptic, coloring, and/or increase the mechanical properties of the material thus formed, said reactive molecules being for example selected from the group comprising amines, polyamines, hydroxylamines, imines, hydrazide and any combination thereof.

Description

The present invention relates to compounds, particularly those based on polysaccharides, that adsorb onto a cellulosic material. The present invention relates in particular to the application of such compounds as reinforcing agents for cellulosic materials, in both wet and dry states. State of the art One of the technical challenges is developing easy-to-use, and preferably inexpensive, reinforcing agents, particularly for industrial applications. Cellulosic materials, such as paper fibers or textile fibers, are widely used in numerous applications (paper and cardboard for packaging, graphic printing, specialty papers, reinforcement for composites, etc.). In many applications, the water sensitivity of these materials is a major obstacle to their use, although their biorenewable nature makes them attractive from a sustainable development perspective. Many additives have already been developed to give treated cellulosic materials Wet Strength (WSE). The solutions recommended in the state of the art generally require specific and more or less complex processes, mostly using compounds derived from petrochemicals and whose toxicity is recognized (glyoxal, formaldehyde, epichlorohydrin, etc.). Furthermore, in general, the additives or reinforcing agents used exhibit either strength-enhancing properties for cellulosic materials in their dry or wet state. However, it is not easy to identify reinforcing agents that enhance the strength of cellulosic materials in both their wet and dry states. The prior art generally uses different additives to fulfill these two technical functions. Therefore, there is an interest in developing new reinforcing agents to overcome this technical problem. Furthermore, existing petrochemical products are generally toxic or suspected of being so. To circumvent this difficulty, dosages are reduced and/or restrictions are placed on the commercial use of these products. In general, for applications where reinforcing agents must be effective in the wet state, currently available solutions are unsatisfactory, particularly because reinforcement requires the use of products toxic materials and heavy processes, or materials with complex structures and/or containing aluminum or plastic sheets. Often, manufacturers will prefer a plastic material, which is unfortunate. We know of the patent US 3,205,125 a papermaking process, comprising a step of adding to the paper pulp before sheet formation 0.1 to 5% of an oxidized polygalactomannan gum, the oxidizing agent being periodic acid or its alkali metal salts and being used in an amount of 0.01 to 0.4 mole per anhydrous hexose unit. We also know about the patent US 5,554,745 Derivatives of galactose-containing polysaccharides containing cationic aldehydes are obtained by oxidation with the enzyme galactose oxidase. The oxidized products have an aldehyde group at a specific position on the polysaccharide, namely the C6 position of the galactose unit. These cationic derivatives are used as paper strength additives. Objectives of the invention The inventors have discovered that a compound according to the present invention makes it possible to solve at least one, and preferably all, of the technical problems mentioned in the present invention. The present invention aims in particular to solve the technical problem of providing a new compound that can serve as a reinforcing agent for a cellulosic material, in particular for reinforcing the strength of the cellulosic material in the dry and/or wet state. The present invention aims to solve the technical problem of providing a cellulosic material that is resistant in particular in the wet state, and preferably in both the dry and wet states. The present invention aims to solve the technical problem of providing a process enabling the controlled preparation of such a compound. The present invention aims in particular to solve the technical problem of providing such a compound, its preparation process in environmentally friendly ways, and in particular to use compounds of natural origin and to limit the use of toxic materials. The present invention aims to solve technical problems in an industrial, reliable, and preferably inexpensive manner without modification of the existing process. Description of the invention In particular, the present invention relates to the preparation of polysaccharide compounds, their complexation with a cellulosic material and their applications, in particular as resistance strengthening agents for cellulosic materials, in dry and/or wet state. The present invention relates to a compound comprising an association of at least one polysaccharide adsorbed on a cellulosic material, said polysaccharide comprising at least two different monosaccharide units, forming first and second monosaccharide units, said second monosaccharide units being branched on a chain comprising at least said first monosaccharide units, at least some of the second monosaccharide units being non-cyclic and bear