WO2019171005A1

WO2019171005A1 - Functionalised material derived from cellulose

Info

Publication number: WO2019171005A1
Application number: PCT/FR2019/050507
Authority: WO
Inventors: François-Xavier FELPIN; Guillaume BRETEL; Erwan LE GROGNEC
Original assignee: Universite De Nantes; Centre National De La Recherche Scientifique
Priority date: 2018-03-08
Filing date: 2019-03-07
Publication date: 2019-09-12
Also published as: FR3078705A1

Abstract

The invention relates to a functionalised material derived from cellulose, to a method for preparing same, and to the use thereof for hydrophobic covalent labelling.

Description

FUNCTIONALIZED MATERIAL DERIVED FROM CELLULOSE

The present invention relates to a functionalized material derived from cellulose, its method of preparation and its use for hydrophobic covalent labeling.

Cellulose is one of the most promising renewable biomass feedstocks with an annual production of 10 ¹¹ to 10 ¹² tonnes. Natural cellulose fibers have many interesting properties such as good mechanical strength, renewable character, biodegradable and non-toxic. As a result, the value of cellulose is widely recognized for various uses, for example as raw material in wood or textile fibers or as a polymer used as an additive in materials, food, cosmetics or pharmaceuticals.

Cellulose-based materials have a strong tendency to absorb moisture due to the high hydrophilicity of cellulose fibers. Although this property may be interesting for certain specific uses, this can be a major disadvantage when the mechanical strength and the physical integrity of the material are degraded by moisture. This problem is particularly prevalent for paper used as packaging or as a printing medium.

The hydrophobization of cellulose therefore represents an interesting opportunity to combine the advantages of natural fibers with properties of moisture resistance and repellence. The approaches traditionally used for the hydrophobization of cellulose rely on the addition of coatings covalently or not, without any spatial control. The control of hydrophobic areas on a cellulose paper is very interesting because it allows applications such as hydrophobic writing, microfluidic devices or parallel synthesis platforms.

The methods developed for the creation of hydrophobic patterns on a cellulose paper are based on the use of wax, poly (dimethylsiloxane), methylsilesquioxane, plasma treatment, photolithography or teflon. All these methods involve the impregnation of the hydrophobic units within the porous structure of the cellulose, without creating chemical bonds with the glucose units composing the cellulose.

On the other hand, the creation of stronger hydrophobic motifs that would be covalently bound to the cellulose surface is still an almost unexplored approach, probably because the synthetic methods allowing spatial control of hydrophobization are very limited. In this area, the work of Bamer-Kowolloik et al. show spatially controlled grafting via a photocatalyzed cycloaddition reaction between a maleimide and a nitrilimine (Adv Funct, Mat, 2012, 22, 304). One of the aims of the invention is to provide a cellulosic material comprising hydrophobic and hydrophilic zones.

Another object of the invention is to provide a cellulosic material comprising a hydrophobic agent grafted covalently on spatially controlled zones.

Another object of the invention is to provide a cellulosic material having hydrophobic zones involved in the manufacture of microfluidic devices, medical devices, moisture-proof packaging or fiduciary systems.

Another object of the invention is to provide a simple process for preparing a cellulosic material having hydrophobic zones.

A first subject of the present invention is a CG-Hyd cellulosic material comprising cellulose covalently functionalized with a hydrophobic agent, characterized in that: a) the cellulose (C) is covalently bonded to a group (G) comprising a sulfur atom, b) the hydrophobic agent (Hyd) is covalently bonded to said group (G) comprising a sulfur atom by a carbon-sulfur bond with said sulfur atom of said group (G), the atom sulfur is not in the delta position of a carbonyl function.

The inventors have unexpectedly developed a cellulosic material covalently functionalized by hydrophobic groups in a controlled manner.

For the purposes of the present invention, the term "cellulosic material" means a material containing cellulose, optionally mixed with other substances. The cellulosic material may be for example paper, that is to say a mixture of cellulose and chemical substances, cardboard, fabric such as cotton, or a composite material comprising cellulose such as cellulose mixtures and synthetic polymers.

Advantageously, the cellulosic material according to the present invention comprises from 0.0001 to 100% by weight of the total weight of the cellulosic cellulose material covalently functionalized by a hydrophobic agent.

In the present invention, the cellulose is covalently functionalized via an oxygen atom of the cellulose, for example via an oxygen-carbon bond. Advantageously, the cellulose is functionalized via a carbonyl function, especially carbamate, thiocarbamate or ester or an ether function with the oxygen atom of the cellulose. The degree of functionalization of the cellulose may vary from 1 to 100%, especially from 10 to 25%.

By "degree of functionalization of cellulose" is meant in the sense of the present invention the average number of primary alcohols of the cellulose reacted with the group (G) and / or with the hydrophobic agent (Hyd). This is the percentage of primary alcohols of the cellulose reacted with the group (G) and / or with the hydrophobic agent (Hyd) per glucose unit.

For the purposes of the present invention, the term "hydrophobic agent" means an agent for reaching contact angles of a drop of aqueous solution (Q) greater than or equal to 120 °.

For the purposes of the present invention, the term "contact angle of a drop of an aqueous solution (Q)" the angle formed by the surface of the solid with the tangent to a drop of an aqueous solution deposited on it solid passing through the edge of the drop (see Figure 1).

The hydrophobic agent may in particular be chosen from the following compounds:

- long linear or branched carbon chains with more than 8 carbon atoms

- derivatives of steroids (eg cholesterol) - derived from terpenes (eg dimonene, myrcene, pinene, ocimene ...)

- silicone type derivatives

- derivatives of fluorinated molecules.

For the purposes of the present invention, the term "sulfur atom not being in the delta position of a carbonyl function" means that the compounds do not contain a sulfur atom bonded to a carbonyl function by an alkyl chain. in C3. For the purposes of the present invention, the term "C ₃ alkyl" means an acyclic carbon chain, saturated, linear or branched, comprising 3 carbon atoms.

The present invention also relates to a CG-Hyd cellulosic material according to the invention, corresponding to the following formula (A):

in which :

m is 1, 2 or 3,

n is 15 to 15,000,

i is 0 or 1,

j is 0 or 1,

p is 0 or 1,

p is 0 and - is a double bond

p is 1 and - is a single bond

L represents a single bond or a spacer,

Y represents NR ^a , O or S, where

R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

X represents a single bond, O or NR ^C , where

R ^c is H, alkyl to C _6, aryl, (Ci-Ce) -aryl,

where C = Y represents CH ₂ and X represents a single bond,

U represents C1-C10 alkyl, aryl- (C1-C6) alkyl,

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

in which Y ', X' and U ', which are identical or different respectively from Y, X and U, have the definition given for Y, X and U,

V represents H, C 1 -C 10 alkyl, aryl or (C 1 -C 6) alkyl-aryl, Hyd represents a hydrophobic agent as defined according to the invention.

In cellulosic materials, the hydrophobic agent Hyd can be bound to cellulose by one, two or three carbon-sulfur bonds.

The present invention also relates to a C-G-Hyd cellulosic material according to the invention, corresponding to the following formula (I):

in which: m is 1, 2 or 3, n is 15 to 15,000, i is 0 or 1, j is 0 or 1, L represents a single bond or a spacer,

Y represents NR ^a , O or S, where

R ^a represents H, alkyl Ci-Ce, aryl, heteroaryl or (Ci-alkyl) -aryl, X represents a single bond, O or NR ^C wherein R ^c is H, alkyl to C _6, aryl (C 1 -C 6) alkylaryl, where C = Y is CH ₂ and X is a single bond,

U represents C1-C10 alkyl, aryl- (C1-C6) alkyl,

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent as defined according to the invention.

For the purposes of the present invention, the cellulose is represented as follows:

The number n of glucose units of the cellulose depends essentially on the type of cellulose used and / or the cellulosic material. The value of n will therefore depend on the cellulosic material used. Typically, n is from 15 to 15,000. In cellulosic materials, the hydrophobic agent Hyd can be bound to cellulose by one, two or three carbon-sulfur bonds.

Advantageously, m is 1 or 2.

The compounds according to the present invention have the following formula when m = 1:

For the purposes of the present invention, the term "spacer" means a group for binding the hydrophobic agent to the rest of the molecule. The spacer may in particular be necessary for synthetic reasons, for example to introduce the double bond or the triple bond useful for the photo-thiol-ene or photo-thiol-yne reaction. The nature of the spacer is not essential in the present invention but it must be chosen so as not to alter the properties of the hydrophobic agent and / or the stability of the CG-Hyd cellulosic material, in particular of formula (I ).

When L is a spacer, it is for example chosen from the group consisting of:

(C, to C ^e) -C and m is 3 or (C₁-Ce) and m is 2 -CH or (C, to C ^e) - CH ₂ - and m is 1,

(alkyl Ci -C _f) -O or (C, to C ₆₎ -OCH ₂ - and m is 1, (C₁-C ₆₎ -NH (CH ₂₎ - and m is 1,

(C ₁ -C ₆ alkyl) -N (CH ₂ ) ₂ - and m is 2,

(alkyl -C ₆₎ -COOCH ₂ - and m is 1, or (C, to C ₆₎ -CON (CH ₂₎ ₂ - and m is 2,

(alkyl -C ₆₎ -NHCO- (C, to C ^e) - and m is 1, (C, to C ₆₎ -NHCO- (alkyleène C ₂ -C ^e) - and m is 1,

(alkyl -C ₆₎ -NHCOO- and m is 1, • (C ₁ -C ₆ alkyl) -NHCOOCH ₂ - and m is 1,

• (C, to C ₆₎ -NHC0- (alkyl Ci-Ce) COO- and m is 1.

• (C, to C ₆₎ -NHC0- (alkyl -C ₆₎ -COOCH ₂ - and m is 1.

For the purposes of the present invention, "L represents a single bond" means that the hydrophobic agent is directly bonded to the carbon carrying the group Z.

For the purposes of the present invention, "X represents a single bond" means that the group C = Y is linked directly to the group U.

For the purposes of the present invention, the term "C1-C6 alkyl" means an acyclic, saturated, linear or branched carbon chain comprising 1 to 6 carbon atoms. These are the methyl, ethyl, propyl, butyl, pentyl and hexyl groups. The definition of propyl, butyl, pentyl, hexyl includes all possible isomers. For example, the term butyl includes n-butyl, n-butyl, n-butyl and tert-butyl.

For the purposes of the present invention, the term "C1-C10 alkyl" means an acyclic carbon chain, saturated, linear or branched, comprising 1 to 10 carbon atoms. These are methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl groups. The definition of propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl and decyl includes all possible isomers. For example, the term butyl includes n-butyl, n-butyl, n-butyl and tert-butyl.

For the purposes of the present invention, the term "aryl" means an aromatic monocycle comprising from 5 to 6 carbon atoms, which can itself be fused with a second saturated, unsaturated or aromatic ring. The term aryl includes, without limitation, phenyl and its derivatives in which one or more hydrogen atoms have been replaced by a group independently selected from alkyl, halogen, alkyl-halogen, hydroxyl, alkoxy, amino, amido, nitro groups. cyano, trifluoromethyl, carboxylic acid or carboxylic ester and naphthyl. Examples of substituted aryl include, without limitation, 2-, 3- or 4- (N, N-dimethylamino) -phenyl, 2-, 3- or 4-cyanophenyl, 2-, 3- or 4-nitrophenyl. 2-, 3- or 4-fluoro-, chloro-, bromo or iodo-phenyl, 2-, 3- or 4-methoxyphenyl.

For the purposes of the present invention, the term "(C 1 -C 8) alkyl-aryl" means a group comprising an acyclic, saturated, linear or branched carbon chain comprising 1 to 6 carbon atoms as defined above. linked to an aryl. An example of (C 1 -C 6) alkyl-aryl is especially the benzyl group.

For the purposes of the present invention, the term "heteroaryl" means an unsaturated, mono- or polycyclic aromatic ring of 5 to 10 members in which one or more of the CH groups have been replaced by one or more heteroatoms. Among the heteroaryls, mention may especially be made of pyridyl, pyrrolyl, furyl, pyrimidyl, thienyl, imidazolyl and pyrrolyl groups.

According to a particular embodiment, the present invention also relates to a C-G-Hyd cellulosic material according to the invention, corresponding to the following formula:

in which: m is 1, 2 or 3, n is 15 to 15,000,

L represents a single bond or a spacer, Y represents NR ^a , O or S, where

R ^a represents H, alkyl Ci-Ce, aryl, heteroaryl or (Ci-alkyl) -aryl, X represents a single bond, O or NR ^C wherein R ^c is H, alkyl to C _6, aryl (C1-C6) alkyl-aryl, or C = Y is CH ₂ and X is a single bond, U is (C1-C10) alkyl, aryl (C1-C6) alkyl,

Z represents H, C 1 -C 10 alkyl, aryl or (C 1 -C 6) alkyl-aryl or a unit:

in which: m is 1, 2 or 3, n is 15 to 15,000,

L represents a single bond or a spacer,

Y represents NR ^a , O or S, where

R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl, X is a single bond, O or NR ^C , where

R ^c is H, alkyl to C _6, aryl, (Ci-Ce) -aryl, where C = Y represents CH ₂ and X represents a single bond,

U represents C1-C10 alkyl, aryl- (C1-C6) alkyl,

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent as defined according to the invention.

wherein m is 1, 2 or 3, n is 15 to 15,000, L is a single bond or a spacer,

Y represents NR ^a , O or S, where R ^a represents H, alkyl Ci-Ce, aryl, heteroaryl or (Ci-alkyl) -aryl, X represents a single bond, O or NR ^C wherein R ^c is H, alkyl to C _6, aryl (C1-C6) alkyl-aryl, or C = Y is CH ₂ and X is a single bond, U is (C1-C10) alkyl, aryl (C1-C6) alkyl,

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

in which Y ', X' and U ', which are the same or different from Y, X and U, respectively, have the given definition for Y, X and U, V represents H, C1-C10 alkyl, aryl or (C1-C4) alkyl. Cr,) - arylC,

Hyd represents a hydrophobic agent as defined according to the invention.

in which: m is 1, 2 or 3, n is 15 to 15,000,

L represents a single bond or a spacer,

Y represents NR ^a , O or S, where

R ^c is H, alkyl to C _6, aryl, (Ci-Ce) aryl, or C = Y is CH ₂ and X is a single bond,

U represents C1-C10 alkyl, aryl- (C1-C6) alkyl,

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent as defined according to the invention. The present invention also relates to a CG-Hyd cellulosic material according to the invention, corresponding to the following formula (I):

in which :

m is 1, 2 or 3,

n is 15 to 15,000,

i is 0 or 1, j is 0 or 1,

L represents a single bond or a spacer,

Y represents NR ^a , O or S, where

R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

X represents a single bond, O or NR ^C , where

R ^c is H, alkyl to C _6, aryl, (Ci-Ce) -aryl,

where C = Y represents CH ₂ and X represents a single bond,

U represents (C1-C10) alkyl, aryl (C1-C6) alkyl, especially (C1-C6) alkyl _.

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

in particular U and U 'are identical, X and X' are identical and Y and Y 'are identical, V is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl,

Hyd represents a hydrophobic agent.

The present invention also relates to a cellulosic material C-G-Hyd according to the invention, corresponding to the following formula (1-1):

in which: m is 1, 2 or 3, n is 15 to 15,000, i is 0 or 1, j is 0 or 1, p is 0 or 1, p is 0 and - is a double bond p is 1 and - is a simple bond

L represents a single bond or a spacer, Y represents NR ^a , O or S, where

R ^c is H, alkyl to C _6, aryl, (Ci-Ce) aryl, or C = Y is CH ₂ and X is a single bond, U represents C1-C10 alkyl, aryl- (C1-C6) alkyl,

Z represents H, C 1 -C 10 alkyl, aryl or (C 1 -C 6) alkyl-aryl or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent as defined according to the invention.

In cellulosic materials, the hydrophobic agent Hyd can be bound to cellulose by one, two or three carbon-sulfur bonds. According to a particular embodiment, the present invention also relates to a C-G-Hyd cellulosic material according to the invention, corresponding to the following formula:

in which: m is 1, 2 or 3, n is 15 to 15,000,

L represents a single bond or a spacer, Y represents NR ^a , O or S, where

R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

X represents a single bond, O or NR ^C , where

U represents C1-C10 alkyl, aryl- (C1-C6) alkyl,

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent as defined according to the invention.

in which: m is 1, 2 or 3, n is 15 to 15,000,

L represents a single bond or a spacer, Y represents NR ^a , O or S, where

R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

X represents a single bond, O or NR ^C , where

R ^c is H, alkyl to C _6, aryl, (Ci-Ce) aryl, or C = Y is CH ₂ and X is a single bond, U represents Ci-Cio alkyl, aryl- (C in Ci to Ce),

V is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl,

Hyd represents a hydrophobic agent as defined according to the invention.

in which: m is 1, 2 or 3, n is 15 to 15,000,

L represents a single bond or a spacer, Y represents NR ^a , O or S, where

R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

X represents a single bond, O or NR ^C , where

U represents C1-C10 alkyl, aryl- (C1-C6) alkyl,

Hyd represents a hydrophobic agent as defined according to the invention.

The present invention relates in particular to the following Cell-en-Chol, Cell-Chol and Cell-Norb compounds:

Cell-ene-Chol

Cell-Norb

By way of nonlimiting examples, the invention also relates to the following compounds:

Cell-F1

Cell-F4

Cell-ene-C8 Cell-ene-C12

The present invention also relates to a CG-Hyd cellulosic material as defined above, with the exception of a compound in which X represents a single bond and U represents an alkyl having 3 carbon atoms in the C = Y and C bonding chain. sulfur atom, and / or X 'represents a single bond and U' represents an alkyl having 3 carbon atoms in the C = Y 'bond chain and the sulfur atom. The present invention also relates to a cellulosic material as defined above, characterized in that U represents (C 1 -C 10) alkyl, in particular Ci.

The present invention also relates to a cellulosic material as defined above, characterized in that U and U 'are identical, X and X' are identical and Y and Y 'are identical.

The present invention also relates to a cellulosic material as defined above, characterized in that the surface of the cellulose covalently functionalized with a hydrophobic agent represents 1 to 99%, in particular 1 to 40%, and especially 5 to 30% of the total surface of the cellulose, and the surface of the cellulose non-functionalised covalently with a hydrophobic agent represents 99 to 1%, in particular 99 to 60%, and in particular 95 to 70% of the total surface area of the cellulose. cellulose.

When the surface of the functionalized cellulose represents more than 40% of the total surface area of the cellulose, the cellulosic material may lose its initial physical properties of insolubility in most solvents and mechanical strength.

The present invention also relates to a cellulosic material as defined above, characterized in that the surface of the cellulose covalently functionalized with a hydrophobic agent represents 1 to 99%, in particular 1 to 40%, and especially 5 to 30% of the total surface of the cellulose, and the surface of the cellulose of hydrophilic nature represents 99 to 1%, in particular 99 to 60%, and in particular 95 to 70% of the total surface of the cellulose.

For the purposes of the present invention, the term "cellulose of hydrophilic nature" means a cellulose for which the contact angle of a drop of aqueous solution (Q) is less than or equal to 60 °.

For the purposes of the present invention, it is considered that the cellulose for which the contact angle of a drop of aqueous solution (Q) is between 60 ° and 120 ° has an intermediate hydrophilic / hydrophobic character.

The present invention also relates to a cellulosic material as defined above, characterized in that the surface of the cellulose covalently functionalized with a hydrophobic agent represents 100% of the total surface area of the cellulose.

The present invention also relates to a cellulosic material as defined above, characterized in that the surface of the cellulose covalently functionalized with a hydrophobic agent represents 1 to 99%, and in particular 5 to 30% of the total surface area of the cellulose. , and the surface of the cellulose non-functionalised covalently by a hydrophobic agent represents 99 to 1% and in particular from 95 to 70% of the total surface of the cellulose, or in that the surface of the cellulose covalently functionalized by an agent hydrophobic represents 100% of the total surface of the cellulose.

The present invention also relates to a cellulosic material as defined above, characterized in that the value of the contact angle of a drop of an aqueous solution (Q) is constant at any point on the surface of the functionalized cellulose of covalently by a hydrophobic agent.

The present invention also relates to a cellulosic material as defined above, characterized in that the difference between the contact angle of a drop of an aqueous solution (Q) on the cellulose functionally covalently functionalized by a hydrophobic agent and the the contact angle of a drop of an aqueous solution (Q) on the non-functionalized cellulose is at least 100 °, in particular at least 110 °, and especially from 120 to 145 °.

The cellulosic material according to the invention thus has the advantage of having well differentiated zones in terms of hydrophilicity and hydrophobicity. In addition, these differentiated zones are obtained directly during functionalization controlled by a hydrophobic agent without the need to regraffer a hydrophilic agent on a material that would have become completely hydrophobic after the first functionalization step.

The present invention also relates to a cellulosic material as defined above, characterized in that the value of the contact angle of a drop of an aqueous solution (Q) is constant at any point on the surface of the functionalized cellulose of covalently by a hydrophobic agent,

and in particular that the difference between the contact angle of a drop of an aqueous solution (Q) on the cellulose functionally covalently functionalized by a hydrophobic agent and the contact angle of a drop of an aqueous solution ( Q) on the non-functionalized cellulose is at least 100 °, in particular at least 110 °, and in particular from 120 to 145 °.

Another subject of the invention is the use of a cellulosic material comprising cellulose functionalised covalently with groups comprising a disulphide function SS, corresponding to formula (II):

in which :

Y and Y ', which may be identical or different, represent NR ^a , O or S,

where R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

X and X ', which are identical or different, represent a single bond, O or NR ^b ,

where C = Y and C = Y 'represent CH ₂ and X and X' represent a single bond,

U is C1-C10 alkyl, aryl-C1-C6 alkyl, where

R ^b is H, alkyl to C _6, aryl, (Ci-Ce) -aryl,

for the covalent attachment of a hydrophobic agent comprising an alkene or alkyne function, said covalent attachment resulting from a photo-thiol-ene or photo-thiol-yne type reaction between said alkene function or said alkyne function and the thiyl radical generated by said disulfide function SS.

The cellulose covalently functionalized with groups comprising a disulfide function SS, corresponding to formula (II), is thus used as synthesis intermediate for the preparation of a CG-Hyd cellulosic material of formula (A) or (I) according to the invention.

For the purposes of the present invention, the term "cellulose functionalised covalently with groups comprising a disulfide function SS" means that part of the hydroxyl functions of D-glucose constituting the cellulose fibers is bonded via a covalent bond to a group containing a sulfur-sulfur bond. Said covalent bond is in particular an OC bond.

In the rest of the present application, the materials will be described as comprising a group containing an S-S bond bonded at each of its ends to a hydroxyl group belonging to two different cellulose fibers. It is, however, likely that a group containing a sulfur-sulfur bond may be bonded to two hydroxyl functions belonging to the same cellulosic fiber. It is also possible that a group containing a sulfur-sulfur bond is bonded to a single hydroxyl function.

Within the meaning of the present invention, the cellulosic material of formula (A) or (I) can be obtained according to the method by photo-thiol-ene reaction with a terminal alkene or photo-thiol-yne with a terminal alkyne (or true alkyne). ).

For the purposes of the present invention, the term "terminal alkene or terminal alkyne" means that the double bond or the triple bond has at one of its ends no substituent other than one or two hydrogens. A terminal alkene will therefore have, at one of its ends, a CH 2 group and a terminal alkyne CH group.

For the purposes of the present invention, the term "resulting from a photo-thiol-ene or photo-thiol-yne reaction between said alkene function or said non-conjugated alkyne function to a carbonyl group and the thiyl radical generated by said SS disulfide function "the fact that the bond between the sulfur and the carbon atom of the binding of the cellulosic material is formed directly from the disulfide function.

Advantageously, it is therefore excluded from the present invention the use of a thiol (SH) to form the C-S bond with the alkene function or the alkyne function. The inventors of the present invention have in fact demonstrated that the use of an S-S disulphide makes it possible to reduce the energy input necessary for the formation of the C-S bond. The least energy required by this reaction makes it possible, among other advantages, to make the preparation of the material less costly but also to limit the degradation of the cellulose, in particular to limit its coloring during the photo-thiol-ene or photo reaction. thiol-yn.

For the purposes of the present invention, the term "photo-thiol-ene or photo-thiol-yne type reaction" means a photocatalyzed thiol-ene or thiol-yn type reaction.

For the purposes of the present invention, the term "photocatalyst" means that the thiyl radical is generated by subjecting the functionalized cellulose by the disulfide function SS to a source of energy sufficient to generate a radical S ·, in particular an ultraviolet irradiation . The photo-thiol-ene or photo-thiol-yne reaction is a reaction well known to those skilled in the art and has been described in numerous books and reviews, for example Hoyle, CE; Bowman, CN Angew. Chem. Int. Ed. 2010, 49, 1540; Hoyle, CE; Lowe, AB; Bowman, CN Chem. Soc. Rev. 2010, 39, 1355; Lowe, AB Polym. Chem. 2010, 1, 17; Lowe, AB Polymer 2014, 55, 5517. The present invention also relates to the use of a cellulosic material as defined above, said material having the formula (II) excluding a compound in which X represents a single bond and U represents an alkyl having 3 carbon atoms in the linking chain C = Y and the sulfur atom, and / or X 'represents a single bond and U' represents an alkyl having 3 carbon atoms in the C = Y 'bonding chain and the atom of sulfur.

The present invention also relates to the use of a cellulosic material as defined above, characterized in that the hydrophobic agent is bonded to a double or triple bond, or contains within its own structure a double or triple bond.

The present invention also relates to the use of a cellulosic material as defined above, characterized in that the hydrophobic agent comprising an alkene or alkyne function corresponds to formula (III):

in which :

m is 1 to 3,

L represents a single bond or a spacer,

Z represents H, C 1 -C 10 alkyl, aryl or (C 1 -C 6) alkyl-aryl or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent, p is 0 and is a triple bond, or

p is 1 and is a double bond.

According to one embodiment, the present invention also relates to the use of a cellulosic material as defined above, characterized in that the hydrophobic agent comprising an alkene function which corresponds to the following formula:

in which :

m is 1 to 3,

L represents a single bond or a spacer,

Z represents H, C1-C10 alkyl, aryl or (C1-C6) alkyl-arylc, or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent,

p is 0 and is a triple bond, or

p is 1 and is a double bond.

According to one embodiment, the present invention also relates to the use of a cellulosic material as defined above, characterized in that the hydrophobic agent comprising an alkyne function which corresponds to the following formula: Hyd

in which :

m is 1 to 3,

L represents a single bond or a spacer,

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent,

According to one embodiment, the present invention also relates to the use of a cellulosic material as defined above, characterized in that the hydrophobic agent comprising an alkyne function has the formula:

Hyd

in which :

m is 1 to 3,

L represents a single bond or a spacer,

Hyd represents a hydrophobic agent,

By way of nonlimiting examples, the hydrophobic agents of formula (III) are the following compounds: 3- (prop-2-yn-1-yloxy) cholesterol

norborn

- molecules with long carbon chains

C8-yne C8-ene

C12-yne C12-ene

- the following fluorinated derivatives

Another subject of the invention is the process for preparing a cellulosic material according to the invention, comprising the reaction of the functionalized cellulose with a group comprising a disulfide function SS as defined according to the invention, with a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiol-ene or photo-thiol-yne reaction between said alkene function or said alkyne function and the thiyl radical generated by said disulfide function SS.

According to one embodiment, the process for preparing a cellulosic material comprises:

the reaction of the functionalized cellulose with a group comprising an S-S disulphide function as defined according to the invention, with a hydrophobic agent comprising an alkyne function, in a photo-thiol-yne type reaction between said alkyne function and the radical thiyl generated by said SS disulfide function leading to the transformation of the alkyne function to alkene function

optionally followed by a photo-thiol-ene reaction between said alkene function and the thiyl radical generated by said disulfide function SS. By way of nonlimiting example, the reaction of the functionalized cellulose with a group comprising a disulfide function SS with 3- (prop-2-yn-1-yloxy) cholesterol successively leads to Cellen-Chol and Cell-Chol. by a photo-thiol-yne reaction followed by a photothiol-ene reaction.

The present invention also relates to the preparation method as defined above, comprising reacting the functionalized cellulose with a group comprising an SS disulfide function as defined according to the invention, with a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiol-ene or photo-thiol-yne reaction between said alkene function or said alkyne function and the thiyl radical generated by said disulfide function SS, in the presence of a solvent, in particular ethyl hexanoate, dimethylsulfoxide, dimethylformamide, acetone, methanol, water or acetonitrile.

The present invention also relates to the process of preparation as defined above, comprising the reaction of the functionalized cellulose with a group comprising an SS disulphide function, with a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-type reaction. thiol-ene or photo-thiol-yne between said alkene function or said alkyne function and thiyl radical generated by said disulfide function SS, especially in the presence of a solvent, in particular ethyl hexanoate, dimethylsulfoxide, dimethylformamide, acetone, methanol, water or acetonitrile. The present invention also relates to the process for preparing a cellulosic material as defined above, comprising the steps of:

(a) covalent functionalization of the cellulose with a group comprising an S-S disulphide function, in particular chosen from:

A compound of formula (IVa):

A compound of formula (IVb):

A compound of formula (IVc):

in which :

Y, Y ', X, X', U and U 'are as defined for formula (I), and

GP and GP ', which are identical or different from one another, represent OH or a leaving group such as halogen, acyl or sulphonate,

under conditions capable of forming a covalent bond between the cellulose and said group comprising an S-S disulfide function to obtain a cellulosic material according to the invention,

(b) reaction between the cellulosic material as defined above and a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiolene or photo-thiol-yne type reaction between said alkene function or said alkyne function and the thiyl radical generated by said disulfide function SS,

to obtain a cellulosic material according to the invention. For the purposes of the present invention, the term "leaving group" means a functional group capable of promoting a nucleophilic substitution reaction.

Such groups include, but are not limited to, activated esters (eg, hydroxybenzotriazole / carbodiimide system, carboxylic anhydrides, acyl chlorides), alkyl halides and alkyl sulfonates.

The present invention also relates to the process for preparing a cellulosic material as defined above, comprising the steps of:

A compound of formula (IVa):

A compound of formula (IVb):

A compound of formula (IVc):

in which :

Y, Y ', X, X', U and U 'are as defined for formula (A) or (I), and

under conditions suitable for forming a covalent bond between cellulose and said group comprising a disulfide function SS, in the presence of an acid, in particular BF -, * Et ₂ 0, the acid paratoluenesulfonic acid or camphorsulfonic acid, to obtain a cellulosic material according to the invention,

(b) reaction between the cellulosic material as defined above and a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiolene or photo-thiol-yne type reaction between said alkene function or said alkyne function and the thiyl radical generated by said disulfide function SS, in the presence of a solvent, in particular ethyl hexanoate, dimethylsulfoxide or acetonitrile,

to obtain a cellulosic material according to the invention.

A compound of formula (IVa):

A compound of formula (IVb):

A compound of formula (IVc):

in which :

Y, Y ', X, X', U and U 'are as defined for formula (A) or (I), and

GP and GP ', which are identical or different from one another, represent OH or a leaving group such as halogen, acyl or sulphonate, under conditions capable of forming a covalent bond between the cellulose and said group comprising a disulphide function SS, especially in the presence of an acid, in particular BF _{3 *} and ₂ 0, paratoluenesulphonic acid or camphorsulfonic acid, to obtain a cellulosic material according to the invention,

(b) reaction between the cellulosic material as defined above and a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiolene or photo-thiol-yne type reaction between said alkene function or said alkyne function and the thiyl radical generated by said disulfide function SS, especially in the presence of a solvent, in particular ethyl hexanoate, dimethylsulfoxide or acetonitrile,

to obtain a cellulosic material according to the invention.

According to a particular embodiment, the present invention also relates to the process for preparing a cellulosic material as defined above, in which the solvent used in the photo-thiol-ene or photo-thiol-yne reaction is the ethyl hexanoate.

According to a particular embodiment, the present invention also relates to the process for preparing a cellulosic material as defined above, in which the acid used in the covalent functionalization of cellulose with a group comprising a disulphide function SS is BR ₃ · Eί ₂ 0.

The cellulosic material C-G-Hyd according to the invention may preferably be prepared according to a process comprising the steps of:

(a) covalent functionalization of the cellulose with a group comprising a disulfide function SS, especially dithiodiglycolic acid, in toluene as solvent, in the presence of BR ₃ · Eί ₂ 0, by heating for 10 to 24 hours at a temperature of 80 to 110 ° C under nitrogen atmosphere and protected from light;

(b) reaction between the functionalized cellulosic material obtained after the first step and a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiol-ene or photo-thiol-yne reaction, in the hexanoate of ethyl as solvent, under UV irradiation, at room temperature for 5 to 150 minutes.

The cellulosic material CG-Hyd according to the invention can advantageously be prepared according to a process comprising the steps of: (a) covalent functionalization of the cellulose with a group comprising a disulphide function SS, especially dithiodiglycolic acid, in toluene as a solvent, in the presence of _3% BF and ₂₀ %, by heating for 24 hours at 10 ° C. under an atmosphere of nitrogen and protected from light;

(b) reaction between the functionalized cellulosic material obtained after the first step and a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiol-ene or photo-thiol-yne reaction, in the hexanoate of ethyl as solvent, under UV irradiation, at room temperature for 150 minutes.

The present invention also relates to the process for preparing a cellulosic material as defined above, in which the solvent used in the photo-thiol-ene or photo-thiol-yne reaction is ethyl hexanoate and the acid used in the covalent functionalization of cellulose with a group comprising a disulfide function SS is in particular BR ₃ · Eί ₂ 0.

Another object of the present invention is the use of a cellulosic material according to the invention for spatially controlled hydrophobic covalent labeling.

For the purposes of the present invention, the term "spatially controlled hydrophobic covalent labeling" means the covalent grafting of hydrophobic agents onto specific areas of a cellulosic support.

Another object of the present invention is the use of a cellulosic material according to the invention in the manufacture of microfluidic devices.

For the purposes of the present invention, the term "microfluidic devices" means devices that comprise a set of miniaturized components allowing the study and analysis of chemical or biological samples.

Another object of the present invention is the use of a cellulosic material according to the invention in the manufacture of medical devices.

Within the meaning of the present invention, the term "medical devices" means any instrument, apparatus, equipment or software intended by its manufacturer to be used in humans for purposes, including, diagnosis, prevention, control, treatment, mitigation of illness or injury.

Another object of the present invention is the use of a cellulosic material according to the invention in the manufacture of protective packaging against moisture. For the purposes of the present invention, the term "protective packaging against moisture" means a hydrophobic cellulosic material used for packaging moisture-sensitive materials by degradation or transformation.

Another object of the present invention is the use of a cellulosic material according to the invention in the manufacture of fiduciary documents.

For the purposes of the present invention, the term "fiduciary documents" means identification and authentication documents, for example passports or identity cards.

The present invention also relates to the use of a cellulosic material according to the invention for spatially controlled hydrophobic covalent labeling, or in the manufacture of microfluidic devices, medical devices, moisture-proof packaging or fiduciary documents.

figures

Figure 1: Angle of contact of a drop of an aqueous solution

Figure 1 shows the contact angle (Q) of a drop of an aqueous solution which corresponds to the angle formed by the surface of the solid (2) with the tangent to a drop (1) of an aqueous solution deposited on this solid passing through the edge of the drop.

Figure 2: Measurements of the contact angle of a drop of an aqueous solution on the Cell-Norb and Cell-Chol samples

Figure 2 shows the photos of a drop of water deposited on the surface of the Cell-Norb, Cell-Chol and Cell-DiS samples as well as the measured Q value for each of these samples.

Examples

Example 1: General Procedure for Pretreatment of Cellulose

A piece of cellulosic filter paper is immersed in a freshly prepared aqueous solution of 10% NaOH (40 mL). The solution is stirred overnight on an orbital shaker at 100 rpm (revolutions per minute). The cellulose sample is then washed six times with 50 mL of ethanol and stored in ethanol. Example 2 Synthesis of Dithiodiglycolic Acid

In a flask, a solution of 10% H ₂ O ₂ (120 mL) and tetrabutylammonium iodide (TBAI, 0.54 mmol) was stirred for 5 minutes. Then thioglycolic acid (3.78 mL, 54.3 mmol) is added to the reaction medium at room temperature with vigorous stirring for 30 minutes. When the reaction is complete (10 minutes), the crude reaction product is filtered and extracted with ethyl acetate (3 x 50 mL). The organic phases are then washed with water (2 ^c 40 mL) and dried over anhydrous MgS0 _4. The solvent is evaporated under reduced pressure to give dithiodiglycolic acid 1 in the form of a white solid (yield = 98%). (Warning: the mixture of H ₂ 0 ₂ and TBAI is very exothermic)

Example 3: Optimization of Cell-DiS Preparation

for details

Input Acid / nb Acid Temperature Time Degree of eq. dithiodiglycolic (° C) (h) Substitution

(eq.) (

1 PTSA / 0.05

110 17

2 PTSA / 0.1

110 17 13

3 PTSA / 0.2

110 17 10 ^a

4 PTSA / 0.5

110 17 ND ^¾C

5 CSA / 0.1

110 17 14

6 BF ₃ .Et ₂ 0 / 0.1

110 17 16

7 BF ₃ .Et ₂ 0 / 0.1

110 24 17

8 BF ₃ .Et ₂ 0 / 0.2

110 24 18

9 BF ₃ .Et ₂ 0 / 0.1

110 24 13

10 BF ₃ .Et ₂ 0 / 0.1

110 24 17

11 BF ₃ .Et ₂ 0 / 0.1

90 24 13 12 BF ₃ .Et ₂ 0 / 0.1

25 24 3 ^a Brown marks frequently observed; ^b ND: Not determined; ^c Paper tinted on its entire surface; PTSA: para-toluenesulfonic acid; CSA: camphorsulfonic acid. Example 4: Preparation of Cell-DiS

Pretreated cellulose filter paper (about 140 mg, 0.86 mmol glucose units) washed 4 times with 40 mL of dry toluene is immersed in dry toluene. A solution of BF ₃ .Et ₂ (11 μL, 0.086 mmol) in toluene (11 mL) is added to the reaction medium, which is then stirred for 5 minutes. Dithiodiglycolic acid (3 equivalents per glucose unit) is then added to the solution. The mixture is stirred for 24 hours at 110.degree. C. under a nitrogen atmosphere, protected from light. The piece of paper is then washed successively with ethanol, methanol, acetone and dichloromethane under sonication. Cell-Dis is dried under vacuum and stored under nitrogen.

Example 5 Synthesis of 3- (prop-2-yn-1-yloxy) cholesterol 3

A solution of cholesterol (1.98 g, 4.90 mmol) in THF (27 mL) under a nitrogen atmosphere is treated with NaH (60% in mineral oil, 294 mg, 7.35 mmol) at room temperature. The suspension is stirred for 30 minutes, then the propargyl bromide is added (80% in toluene, 727 μL, 6.13 mmol) and the reaction mixture is stirred at 50 ° C. for 24 hours. The solution is then quenched with methanol (10 mL) and the solvent is removed by evaporation under reduced pressure. The solid obtained is dissolved in CHCl (50 mL) and washed with water (2 × 20 mL) and saturated NaCl solution (20 mL). The organic phase is dried over MgSO ₄ , filtered and concentrated under reduced pressure. The crude product is then purified by flash chromatography on silica gel (100% petroleum ether) to give the expected product 3 in the form of a white solid (1.98 g, yield = 95%).

Melting point: 104-106 ° C. ^l U NMR (400MHz, CDC1 _3, ppm): ¾ 5.36-5.37 (m, 1H), 4.19 (d, 2H, J = 2.4 Hz), 3.35-3.43 (m, 1H), 2.68-2.76 (m, 1H), 2.36-2.41 (ddd, 1H, J = 2.3 Hz, 4.8 Hz, 13.1 Hz), 2.40 (t, 1H, J = 2.4 Hz), 2.20-2.26 (m, 1H), 1.79-2.05 (m, 5H), 1.44-1.61 (m, 7H), 1.26-1.40 (m, 4H), 1.00-1.21 (m, 9H), 1.01 (s, 3H), 0.93 (d, 3H, J = 6.5 Hz), 0.88; (dd, 6H, J = 1.7 Hz, 6.6 Hz), 0.69 (s, 3H). ¹³ C NMR (100 MHz, CDCl ₃ , ppm): S _c 140.7, 122.0, 80.6, 78.3, 73.9, 56.9, 56.3, 55.2, 50.3, 42.5,

39.9, 39.7, 38.9, 37.3, 36.9, 36.3, 35.9, 32.1, 32.0, 28.4, 28.2, 28.1, 24.4, 24.0, 22.9, 22.7, 21.2, 19.5,

18.9, 12.0.

Example 6: Preparation of Cell-Norb

A mixture of norbornene 2 (100 mg, 1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass vessel. Then 12 mg of Cell-DiS are placed between a photomask and an aluminum plate (2 x 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. Finally, Cell-Norb is washed successively with ethanol, methanol, acetone and dichloromethane, sonicated, dried under vacuum and stored under nitrogen.

Example 7 Preparation of Cell-en-Chol

A mixture of 3- (prop-2-yn-1-yloxy) cholesterol 3 (451 mg, 1,062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tub. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, Cell-ene-Chol is washed successively with ethanol, methanol, acetone and dichloromethane, under sonication, dried under vacuum and stored under nitrogen.

Example 8: Preparation of Cell-Chol A mixture of Cell-ene-Chol (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tub. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, Cell-Chol is washed successively with ethanol, methanol, acetone and dichloromethane, sonicated, dried under vacuum and stored under nitrogen.

Example 9 Preparation of cellulosic Cell-Fl materials

A mixture of hydrophobic agent F1, defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tank. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, the Cell-F1 material is washed successively with ethanol, methanol, acetone and dichloromethane, under sonication, dried under vacuum and stored under nitrogen. Cell-F1

Example 10 Preparation of cellulosic Cell-F2 Materials

A mixture of hydrophobic agent F 2, defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tank. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, the Cell-F2 material is washed successively with ethanol, methanol, acetone and dichloromethane, under sonication, dried under vacuum and stored under nitrogen.

Cell-F2

Example 11 Preparation of Cellulosic Cell-F3 Materials

A mixture of hydrophobic agent F3, defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tank. Then 12 mg of Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes. with strong agitation. Finally, the Cell-F3 material is washed successively with ethanol, methanol, acetone and dichloromethane, sonicated, dried under vacuum and stored under nitrogen.

Cell-F3

Example 12 Preparation of cellulosic materials Cell-F4 A mixture of the hydrophobic agent F4 defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in hexanoate of ethyl (6 mL) is placed in a glass vessel. Then 12 mg of Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _{it1 1c} = 365 nm) for 150 minutes with stirring. strong. Finally, the Cell-F4 material is washed successively with ethanol, methanol, acetone and dichloromethane, sonicated, dried under vacuum and stored under nitrogen.

Cell-F4

Example 13 Preparation of cellulosic Cell-C8 Materials

A mixture of the hydrophobic agent C8-enene, defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tub. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, the Cell-C8 material is washed successively with ethanol, methanol, acetone and dichloromethane, sonicated, dried under vacuum and stored under nitrogen.

Cell-C8

Example 14 Preparation of cellulosic Cell-ene-C8 Materials

A mixture of the hydrophobic agent C8-yne, defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tub. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, the Cell-ene-C8 material is washed successively with ethanol, methanol, acetone and dichloromethane, under sonication, dried under vacuum and stored under nitrogen.

Example 15 Preparation of Cellulosic Cell-C12 Materials

A mixture of the hydrophobic agent Cl 2 -ene, defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass tub. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, the Cell-C8 material is washed successively with ethanol, methanol, acetone and dichloromethane, sonicated, dried under vacuum and stored under nitrogen.

Cell-C12

EXAMPLE 16 Preparation of cellulosic Cell-ene-C12 Materials A mixture of the hydrophobic agent Cl2-yne, defined below (1.062 mmol) and 2,2-dimethoxy-2-phenylacetophenone (40 mg, 0.16 mmol) in ethyl hexanoate (6 mL) is placed in a glass vessel. Then 12 mg Cell-DiS are placed between a photomask and an aluminum plate (2 × 2.5 cm), immersed in the solution and irradiated under UV light (l _iticc = 365 nm) for 150 minutes with vigorous stirring. . Finally, the Cell-ene-C12 material is washed successively with ethanol, methanol, acetone and dichloromethane, under sonication, dried under vacuum and stored under nitrogen.

C12-yne Cell-ene-C12 Example 17 Measurement of the Hydrophobicity of the Synthesized Compounds

The contact angle is measured on a Kruss brand "Drop Shape Analyzer". The resolution of the camera coupled to the device is 1024x768 pixels, the volume of the drop of water is 1.0 μL and the diameter of the needle is 0.514 mm. The images in FIG. 2 represent the measurements of the contact angle Q of a water drop for Cell-Norb, Cell-Chol and Cell-DiS with angle values determined at 125.3 ± 1.4 °, 140. 8 ± l. 1 ° and 0 °, respectively.

Claims

Cellulosic material C-G-Hyd comprising cellulose functionalised covalently by a hydrophobic agent, characterized in that:

a) the cellulose (C) is covalently bound to a group (G) comprising a sulfur atom, b) the hydrophobic agent (Hyd) is covalently bonded to said group (G) comprising a sulfur atom by a carbon-sulfur bond with said sulfur atom of said group (G), the sulfur atom not being in the delta position of a carbonyl function,

having the following formula (A):

L represents a single bond or a spacer, Y represents NR ^a , O or S, where

U represents alkyl Cl-Ce, aryl- (C, to C _6),

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl or a unit:

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent.

2. Cellulosic material C-G-Hyd according to claim 1, corresponding to the following formula (I):

in which :

m is 1, 2 or 3,

n is 15 to 15,000,

i is 0 or 1, j is 0 or 1,

L represents a single bond or a spacer,

Y represents NR ^a , O or S, where

R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

X represents a single bond, O or NR ^C , where

R ^c is H, alkyl to C _6, aryl, (Ci-Ce) -aryl,

where C = Y represents CH ₂ and X represents a single bond,

U represents (C1-C6) alkyl, aryl (C1-C6) alkyl, especially (C1-C6) alkyl _.

Z represents H, C 1 -C 10 alkyl, aryl or (C 1 -C 6) alkyl-aryl or a unit:

in particular U and U 'are identical, X and X' are identical and Y and Y 'are identical,

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent.

3. CG-Hyd cellulosic material according to claim 1, corresponding to the following formula:

in which: m is 1, 2 or 3, n is 15 to 15,000,

L represents a single bond or a spacer,

Y represents NR ^a , O or S, where

U represents alkyl Cl-Ce, aryl- (C, to C _6),

V is H, C1-C10 alkyl, aryl or (C1-C6) alkylaryl,

Hyd represents a hydrophobic agent.

4. CG-Hyd cellulosic material according to one of claims 1 to 3, excluding a compound in which X represents a single bond and U represents an alkyl having 3 carbon atoms in the C = Y bonding chain and the sulfur atom, and / or X 'represents a single bond and U' represents an alkyl having 3 carbon atoms in the C = Y 'bond chain and the sulfur atom.

5. Cellulosic material according to one of claims 1 to 4, characterized in that the surface of the cellulose covalently functionalized with a hydrophobic agent represents 1 to 99%, and in particular from 5 to 30% of the total surface area of the cellulose, and the surface of the cellulose non-covalently functionalized with a hydrophobic agent represents 99 to 1% and especially 95 to 70% of the total surface area of the cellulose, or in that the surface of the cellulose covalently functionalized with a hydrophobic agent represents 100% of the total surface area of the cellulose.

6. Cellulosic material according to one of claims 1 to 5, characterized in that the value of the contact angle of a drop of an aqueous solution (Q) is constant at any point on the surface of the functionalized cellulose covalently by a hydrophobic agent and in particular that the difference between the contact angle of a drop of an aqueous solution (Q) on the cellulose covalently functionalized by a hydrophobic agent and the contact angle of a drop of an aqueous solution (Q) on the non-functionalized cellulose is at least 100 °, especially at least 110 °, and especially from 120 to 145 °.

7. Use of a Cellulosic Material Comprising Covalently Functionalized Cellulose by Groups Comprising an S-S Disulfide Function, Having the Formula (II):

in which :

Y and Y ', which may be identical or different, represent NR ^a , O or S,

where R ^a is H, C1-C6 alkyl, aryl, heteroaryl or (C1-C6) alkylaryl,

where C = Y and C = Y 'represent CH ₂ and X and X' represent a single bond, U is C1-C10 alkyl, aryl-C1-C6 alkyl, where

R ^b is H, alkyl to C _6, aryl, (Ci-Ce) -aryl,

8. Use of a cellulosic material according to claim 7, said material having the formula (II) excluding a compound wherein X represents a single bond and U represents an alkyl having 3 carbon atoms in the linker chain C = Y and the sulfur atom, and / or X 'represents a single bond and U' represents an alkyl having 3 carbon atoms in the C = Y 'bonding chain and the sulfur atom.

9. Use according to one of claims 7 or 8, characterized in that the hydrophobic agent comprising an alkene or alkyne function corresponds to formula (III):

in which :

m is 1 to 3,

L represents a single bond or a spacer,

Z is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

V is H, C1-C10 alkyl, aryl or (C1-C6) alkyl-aryl,

Hyd represents a hydrophobic agent,

p is 0 and is a triple bond, or

p is 1 and is a double bond.

10. Process for the preparation of a cellulosic material according to one of claims 1 to 6, comprising the reaction of the functionalized cellulose with a group comprising a disulfide function SS as defined in claim 7, with a hydrophobic agent comprising a function an alkene or an alkyne function, in a photo-thiol-ene or photo-thiol-yne reaction between said alkene function or said alkyne function and the thiyl radical generated by said function SS disulfide, especially in the presence of a solvent, especially ethyl hexanoate, dimethylsulfoxide, dimethylformamide, acetone, methanol, water or acetonitrile.

11. Process for preparing a cellulosic material according to one of claims 1 to 6, comprising the steps of:

A compound of formula (IVa):

A compound of formula (IVb):

A compound of formula (IVc):

in which :

Y, Y ', X, X', U and U 'are as defined for formula (I), and

under conditions suitable for forming a covalent bond between cellulose and said group comprising a disulfide function SS, especially in the presence of an acid, in particular BF -, * Et ₂ 0, para-toluenesulfonic acid or camphorsulfonic acid to give a cellulosic material according to claim 7,

(b) reaction between the cellulosic material according to claim 7 and a hydrophobic agent comprising an alkene function or an alkyne function, in a photo-thiol-type reaction. enene or photo-thiol-yne between said alkene function or said alkyne function and the thiyl radical generated by said disulfide function SS, especially in the presence of a solvent, in particular ethyl hexanoate, dimethylsulfoxide or acetonitrile,

to obtain a cellulosic material according to one of claims 1 to 6.

12. Method according to one of claims 10 or 11, wherein the solvent used in the photo-thiol-ene or photo-thiol-yne type reaction is ethyl hexanoate and the acid used in the covalent functionalization. cellulose with a group comprising a disulphide function SS is in particular BR ₃ · Eί ₂ 0.

Use of a cellulosic material according to one of claims 1 to 6 for spatially controlled hydrophobic covalent labeling, or in the manufacture of microfluidic devices, medical devices, moisture-proof packaging or fiduciary documents.