BIOSOURCED POLYMER FOR MANUFACTURING, VIA CATALYTIC CARBONATION, A NON-BITUMINOUS POLYHYDROXYURETHANE BINDER FOR ROADWAY OR CIVIL ENGINEERING-RELATED USES

Abstract

The invention relates to a biosourced polymer obtained by dual chemical functionalization of chitosan, usable for catalytic carbonation of cyclic ethers by means of carbon dioxide, and a binder composition for creating layers and/or coatings for road construction and/or civil engineering, marking materials, or sealing or insulation materials. Said composition contains a polyhydroxyurethane polymer binder resulting from the reaction of at least one polyamine with at least one polycyclocarbonate. Said polycyclocarbonate was obtained by carbonating a (cyclic) poly(ether) with carbon dioxide catalyzed by said biosourced polymer.

Claims

1-15. (canceled)

16. Biosourced polymer obtained by functionalization of chitosan in a manner such that it comprises monomer units of formulas A and B: ##STR00012## wherein M.sup.+ is a cation, X.sup. is an anion, L.sub.1 and L.sub.2 are, independently of one another, a divalent group, GA is an anionic group, and GC is a cationic group.

17. Biosourced polymer according to claim 16, wherein GA is the carboxylate group.

18. Biosourced polymer according to claim 16, wherein GC is a quaternary ammonium group.

19. Biosourced polymer according to claim 16, further defined as being obtained by functionalization of chitosan so that it comprises monomer units of formulas A2 and B2: ##STR00013## wherein M.sup.+ is a cation and X.sup. is an anion.

20. Biosourced polymer according to claim 16, wherein M.sup.+ represents K.sup.+ and X.sup. represents I.sup..

21. Binder composition for making road construction and/or civil engineering layers and/or coatings, marking products, or sealants or insulating products, comprising a polymer binder of polyhydroxyurethane nature, derived from the reaction of at least one polyamine with at least one polycyclocarbonate, wherein the polycyclocarbonate was obtained by carbonation of a poly(cyclic ether) with carbon dioxide catalyzed by a biosourced polymer according to claim 16.

22. Binder composition according to claim 21, wherein the poly(cyclic ether) is a poly(epoxide).

23. Binder composition according to claim 22, wherein the poly(cyclic ether) is a diepoxide.

24. Binder composition according to claim 21, wherein the polyamine is a diamine and the polycyclocarbonate is a dicyclocarbonate.

25. Binder composition according to claim 21, wherein the cyclocarbonate groups of the polycyclocarbonate are a 5 or 6-membered ring.

26. Binder composition according to claim 21, wherein the polyhydroxyurethane was formed without using isocyanate reagents.

27. Method for carbonation with carbon dioxide, comprising the following steps: providing a cyclic ether; subjecting said cyclic ether to a carbonation reaction with carbon dioxide catalyzed by a biosourced polymer of claim 16, and recovering a cyclocarbonate.

28. Method according to claim 27, wherein the cyclic ether is a poly(cyclic ether) and the cyclocarbonate is a polycyclocarbonate.

29. Method according to claim 28, further comprising the following step: subjecting said polycyclocarbonate to a polycondensation reaction in the presence of at least one polyamine to obtain a polymer binder of polyhydroxyurethane nature, said binder comprising a polymer binder of polyhydroxyurethane nature, derived from the reaction of at least one polyamine with at least one polycyclocarbonate, wherein the polycyclocarbonate was obtained by carbonation of a poly(cyclic ether) with carbon dioxide catalyzed by a biosourced polymer obtained by functionalization of chitosan in a manner such that it comprises monomer units of formulas A and B: ##STR00014## wherein M.sup.+ is a cation, X.sup. is an anion, L.sub.1 and L.sub.2 are, independently of one another, a divalent group, GA is an anionic group, and GC is a cationic group.

30. Method according to claim 27, wherein the carbonation reaction is carried out at a temperature of less than or equal to 100 C. under a carbon dioxide pressure of less than 10 bar for less than 4 hours.

31. Material for making road construction and/or civil engineering layers and/or coatings, comprising a binder composition according to claim 21.

32. The material of claim 31, further comprising an aggregate.

Description

EXAMPLES

I. Materials Used

[0136] Chitosan used is chitosan 652, derived from shrimp shells, provided by the France Chitine company (Marseille, France), having a degree of acetylation (DA) in the order of 10%, a molecular weight of about 150,000 g/mol and a hydration rate of 10% by weight (determined by thermogravimetric analysis). It is soluble in aqueous solutions of pH<6.

[0137] The allyl glycidyl ether (97%, Alfa Aesar), glycidyl trimethyl ammonium chloride (>90%, Aldrich), 4,4-azobis(4-cyanovaleric acid) (>75%, Aldrich), 3-mercaptopropionic acid (>99%, Aldrich) and potassium iodide (99.5%, Aldrich) were used as received.

II. Preparation of a Catalyst According to the Invention Based on Functionalized Chitosan

[0138] The catalyst used in the examples according to the invention was prepared in three steps.

[0139] 1.sup.st step: In a three-necked 250 ml flask, 100 mL of deionized water which is heated to 85 C. were introduced. Then under stirring, 2 g of chitosan (10.9 mmol of primary amino moieties, 1 eq.) are gradually dispersed in the aqueous solution. 1.65 g of glycidyl trimethyl ammonium chloride (9.79 mmol, 0.9 eq.) and 0.60 g of allyl glycidyl ether (5.26 mmol, 0.48 eq.) are then added dropwise to the reaction medium. The same amounts of these two reagents are added after 24 hours and then after 48 hours of reaction. The reaction was stopped after 72 hours. The reaction medium is precipitated in acetone and dried in a vacuum oven at 45 C. for 48 hours. 2.55 g of a white powder were recovered. The functionalization rates of chitosan primary amine moieties were determined by .sup.1H-NMR. The resulting ratio of allyl functions/ammonium functions is 70/30. The compound obtained comprises monomer units of the formulas A and B2 wherein X.sup. is chloride anion:

##STR00010##

[0140] 2.sup.nd step: 0.5 g of functionalized chitosan (1 eq of allyl functions) obtained in the previous step is dissolved in 20 mL of deionized water by heating the solution to 50 C. After dissolution and cooling to room temperature, 0.1 g of 4,4-azobis(4-cyanovaleric acid) (about 0.2 eq.) previously dissolved in 2 mL of methanol and 2 g of mercaptopropionic acid (about 15 eq.) are added. After 20 minutes of bubbling with argon, the stirred mixture is heated to 70 C. The reaction is stopped after 20 hours, the pH is adjusted to 5.5 with a sodium hydroxide solution and the polymer is recovered after precipitation in acetone, dissolved in water, precipitated again and then dried in a vacuum oven at 45 C. for 48 hours. 0.47 g of a slightly yellow powder is obtained. .sup.1H-NMR showed that the reaction was quantitative (100% conversion of the allyl functions into carboxylic functions). The compound obtained comprises monomer units of the formulas A and B2:

##STR00011##

[0141] In a 3.sup.rd step, the catalyst according to the invention is formed by association in the reaction medium of the precursor compound obtained above with an equimolar amount of a salt of formula MX, such as KI.

III. Procedure of the Catalytic Carbonation Reaction of Cyclic Ethers

[0142] In a 50 mL autoclave, cyclic ether (20.83 mmol), the chitosan compound prepared above having monomer units of formulas A and B1 (0.125 mmol, 0.6%), and potassium iodide (0.125 mmol) are introduced. Carbon dioxide (7 bar, 99.999%) is then added, and the reaction conducted at 80 C. for typically 2 to 4 hours. The progress of the reaction can be monitored by .sup.1H-NMR. At the end of the reaction, the reaction mixture is filtered and distilled to separate the catalyst.

IV. Comparison of the Catalyst According to the Invention to Other Biosourced Catalysts of Cyclic Ether Carbonation

[0143] In order to highlight the high efficiency of the catalytic system according to the invention, the performance thereof (Example 1) was compared with those of one of the most efficient catalytic systems known, the lecithin/KI system (Comparative Example 1), which also presents the advantage of using a biosourced compound, a soy lecithin. These two catalysts were used in their optimal operating conditions to achieve the standard monoepoxide carbonation under carbon dioxide pressure. Two other catalytic systems based on partially functionalized chitosan were tested (Comparative Examples 2 and 3). Table 1 shows the reaction times and yields obtained for the various tested epoxy substrates.

TABLE-US-00003 TABLE 1 Example 1 Comp. 1 Comp. 2 Comp. 3 Epoxy Catalytic System Comparative test: Comparative experiment: Comparative experiment: Substrate of the invention Lecithin/KI 1.25% (b) Chitosan functionalized only Chitosan functionalized only 0.6% (a) with the glycidyl trimethyl with the glycidyl trimethyl ammonium chloride 0.8% (c) ammonium chloride 0.8% + KI 0.8% (a) Allyl glycidyl ether 98% (2 h)* 98% (4 h) 20% (24 h) 28% (4 h30) Epichlorohydrin 96% (7 h) 96% (12 h) Operating conditions (a) 7 bar, 80 C. (b) 20 bar, 100 C. (c) 15 bar, 80 C. Mol %. *Results unchanged after 4 recycles of the chitosan part of the catalyst.

[0144] The catalytic system according to the invention comprises monomer units of the formulas A and B, wherein the complexed salt MX is potassium iodide (KI). It allows the carbonation reaction to be conducted under milder conditions, which demonstrates an interesting security aspect. The amounts of catalyst used to achieve complete reaction are halved compared to the catalytic system based on lecithin. The catalysts based on chitosan functionalized only with glycidyl trimethyl ammonium chloride (formation of B type monomer units) lead in turn to low yields, indicating that the simultaneous presence of the A and B monomer units is required.

[0145] It was also shown that chitosan part of the catalytic system according to the invention can be repeatedly recycled without loss of activity (after washing with acetone and drying for 18 hours at 40 C. The KI salt can in turn be recovered in the acetone fraction), confirming its very good thermal stability under the conditions of the reaction.

V. Preparation of Polycyclocarbonate by Carbonation of Poly(Cyclic Ether) Catalyzed by the Catalyst According to the Invention

[0146] Since carbon dioxide is gaseous, the reaction is carried out in a 50 ml Parr Hastelloy autoclave equipped with a pressure gauge, a rupture disc and gas introduction and release valves. An electronic device controls both stirring and heating of the autoclave. 10 g (33.07 mmol) of tri-epoxidized trimethylolpropane, 0.39 mmol of the chitosan compound prepared above having monomer units of the formulas A and B1 and 64.23 mg (0.39 mmol) of potassium iodide are introduced. The autoclave is then pressurized to 20 bar of nitrogen for 1 hour to check tightness. The device is considered to be sealed if no pressure reduction is noted during the time of observation. The synthesis protocol can then proceed. The nitrogen is discharged and then the autoclave is placed under vacuum for 30 minutes. 7 bar of carbon dioxide are introduced at room temperature (22 C.). The autoclave is then heated to 80 C. and maintained under constant vigorous stirring. The reaction is stopped after 3 hours. The reactor is then degassed and the reaction residue is collected and filtered hot through filter paper. A colorless oil is obtained. 14.08 g (32.41 mmol) of tricyclocarbonate compound are recovered with a yield of 98% and present the characteristic NMR signals described in the literature (cf. European Polymer Journal, 2014, 55, 17-26).

VI. Preparation of a Polyhydroxyurethane Polymer Binder According to the Invention

[0147] 6 g (13.8 mmol) of polycyclocarbonate prepared in the preceding step and 2.61 g (13.8 mmol, 1 equiv.) of polyamine TEPA (tetraethylene pentamine) are reacted in a silicone mold, at 100 C. for 12 hours and then at 200 C. for 2 hours. The polyhydroxyurethane polymer obtained has a glass transition temperature of 56 C., a THF soluble fraction equal to 1% by weight and a swelling rate of 0.6%, showing its perfect polymerization.