BIOSOURCED COMPOUND HAVING EPOXIDE FUNCTIONS, METHOD FOR THE SYNTHESIS OF SUCH A COMPOUND, AND USE THEREOF FOR PRODUCING EPOXY RESIN

Abstract

A compound has at least one epoxide function which can be synthesized by an epoxidation reaction of a compound having at least one hydroxyl function obtained by depolymerization of condensed tannins by a nucleophile selected from furan and the derivatives thereof. The compound having at least one epoxide function has properties that are useful in the production of epoxy resins, as a synthon precursor and/or as a starting material for forming a polyamine hardener.

Claims

1. A compound having one or more epoxide function(s) of general formula (I): ##STR00047## wherein: R.sub.1, R.sub.2 and R.sub.3, which is identical or different, each represent a hydrogen atom, a group of formula (III), or a group OR.sub.9 where R.sub.9 represents a protective group for a hydroxyl function: ##STR00048## and (R.sub.1 and R.sub.2) or (R.sub.2 and R.sub.3) together represent a group of general formula (IV): ##STR00049## wherein R.sub.8 represents a hydroxyl group, a group of formula (III), or a group OR.sub.9 where R.sub.9 represents a protective group for a hydroxyl function, R.sub.4 represents a hydrogen atom, a hydroxyl group, optionally protected with a protective group, a group of formula (III) or a group OR.sub.7, wherein R.sub.7 represents a group of general formula (II): ##STR00050## wherein R.sub.1, R.sub.2 and R.sub.3, which is identical or different, each represent a group of formula (III), or a group OR.sub.9 where R.sub.9 represents a protective group for a hydroxyl function, R.sub.5 represents a hydrogen atom, a group of formula (III), or a group OR.sub.9 where R.sub.9 represents a protective group for a hydroxyl function, R.sub.6 represents a group of formula (III), or a group OR.sub.9 where R.sub.9 represents a protective group for a hydroxyl function, and R represents a furan nucleus, which may optionally be substituted, at least one substituent among R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.8, R.sub.1, R.sub.2 and R.sub.3 representing a group of formula (III), or a salt thereof.

2. The compound comprising one or more epoxide function(s) as claimed in claim 1, wherein at least two substituents among R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5, R.sub.6, R.sub.8, R.sub.1, R.sub.2 and R.sub.3 represent a group of formula (III).

3. A synthesis method for synthesizing a compound having one or more epoxide function(s) as claimed in claim 1, further comprising a step of epoxidation of a compound of general formula (V): ##STR00051## wherein: R.sub.11, R.sub.12, R.sub.13 and R.sub.15, which is identical or different, each represent a hydrogen atom or a hydroxyl group, optionally protected with a protective group, R.sub.14 represents a hydrogen atom or a group OR.sub.17, wherein R.sub.17 represents a hydrogen atom, a protective group for a hydroxyl function or a group of general formula (II): ##STR00052## wherein R.sub.11, R.sub.12 and R.sub.13, which is identical or different, each represent a hydroxyl group, optionally protected with a protective group, R.sub.16 represents a hydroxyl group, optionally protected with a protective group, and R represents a furan nucleus, optionally substitutable, at least one substituent among R.sub.11, R.sub.12, R.sub.13, R.sub.14, R.sub.15, R.sub.16, R.sub.11, R.sub.12 and R.sub.13 representing a hydroxyl group, or a salt thereof.

4. The synthesis method as claimed in claim 3, wherein the epoxidation of the compound of general formula (V) is carried out by placing said compound of general formula (V) in the presence of an epihalohydrin.

5. A synthesis method as claimed in claim 3, wherein the compound of general formula (V) is obtained by a reaction of depolymerization of condensed tannins in the presence of an acid by means of a nucleophile of general formula (VII): ##STR00053## wherein R.sub.11, R.sub.12, R.sub.13 and R.sub.14, which is identical or different, each represent a hydrogen atom or a substituent not comprising a mesomeric-effect electron-withdrawing group conjugated to the furan nucleus, at least one substituent among R.sub.11, R.sub.12, R.sub.13 and R.sub.14 representing a hydrogen atom.

6. The synthesis method as claimed in claim 5, wherein the epoxidation step is carried out on the reaction crude obtained by the reaction of condensed-tannin depolymerization in the presence of an acid by means of the nucleophile of general formula (VII).

7. A method for producing an epoxy resin using a compound having one or more epoxide function(s) as claimed in claim 1.

8. A method for producing an epoxy resin using a compound having one or more epoxide function(s) as claimed in claim 2, and constitutes a precursor synthon for said epoxy resin.

9. A method for producing an epoxy resin using a compound having one or more epoxide function(s) as claimed in claim 2, and is subjected, in order to form a compound constituting a precursor synthon for said epoxy resin, to a step of opening at least one of its epoxide rings by reaction with a nucleophilic reagent having a function capable of reacting with said epoxide ring so as to cause opening thereof, with an exclusion of an amine function, and having no other group that is reactive with respect to the epoxide functions, said step being carried out to leave intact at least one epoxide ring of said compound having one or more epoxide function(s).

10. The method as claimed in claim 7, wherein the compound having one or more epoxide function(s) is subjected to a step of opening at least one of its epoxide rings with introduction of an amine function, so as to form a curing agent for the production of said epoxy resin.

11. A method for producing an epoxy resin, by mixing at least one epoxide prepolymer and a curing agent in accordance with claim 2, wherein at least one of: said epoxide prepolymer is a compound comprising epoxide functions, or is obtained from a compound comprising epoxide functions by a step of opening at least one of its epoxide rings by reaction with a nucleophilic reagent having a function capable of reacting with said epoxide ring so as to cause opening thereof, with an exclusion of an amine function, and having no other group that is reactive with respect to the epoxide functions, said step being carried out so as to leave intact at least one epoxide ring of said compound having one or more epoxide function(s); and said curing agent is obtained from a compound having one or more epoxide function(s) by a step of opening at least one epoxide ring of said compound having one or more epoxide function(s) with introduction of an amine function.

12. The method for producing the epoxy resin as claimed in claim 11, wherein the step of opening at least one epoxide ring of the compound having one or more epoxide function(s) with an introduction of an amine function is carried out by placing said compound having one or more epoxide function(s) in the presence of a compound, called functionalization compound, comprising a first function capable of reacting with the epoxide ring so as to cause opening thereof, and a second function being a primary amine function, or in a presence of ammonia.

13. The method for producing an epoxy resin as claimed in claim 12, wherein the functionalization compound is cysteamine.

14. The method for producing an epoxy resin as claimed in claim 11, wherein the step of opening at least one epoxide ring of said compound having one or more epoxide function(s) with an introduction of an amine function is preceded by, or carried out simultaneously with, a step of opening at least one of the epoxide rings of said compound having one or more epoxide function(s) by reaction with a nucleophilic reagent having a function capable of reacting with said epoxide ring so as to cause opening thereof, with the exclusion of an amine function, and having no other group that is reactive with respect to the epoxide functions, said step being carried out so as to leave intact at least one epoxide ring of said compound having one or more epoxide function(s) for the step of opening said epoxide ring with the introduction of an amine function.

15. An epoxy resin obtained by the method as claimed in claim 11.

16. The epoxy resin as claimed in claim 15 to obtain materials for insulating electrical and/or electronic components.

17. The epoxy resin as claimed in claim 15 to manufacture materials to be in contact with food.

18. A compound having one or more amine function(s) obtained by a step of opening at least one epoxide ring of a compound having one or more epoxide function(s) as claimed in claim 1 with an introduction of an amine function, or a salt thereof.

19. The compound having one or more amine function(s) as claimed in claim 18, corresponding to general formula (VIII): ##STR00054## wherein: R.sub.21, R.sub.22 and R.sub.23, which is identical or different, each represent a hydrogen atom, a group of formula (IX) below, or a group OR.sub.29 where R.sub.29 represents a protective group for a hydroxyl function, and (R.sub.21 and R.sub.22) or (R.sub.22 and R.sub.23) together represent a group of general formula (X): ##STR00055## wherein R.sub.28 represents a hydroxyl group, a group of formula (IX) below, or a group OR.sub.29 where R.sub.29 represents a protective group for a hydroxyl function, R.sub.24 represents a hydrogen atom, a hydroxyl group, optionally protected with a protective group, a group of formula (IX) below or a group OR.sub.27, wherein R.sub.27 represents a group of general formula (XI): ##STR00056## wherein R.sub.21, R.sub.22 and R.sub.23, which is identical or different, each represent a group of formula (IX) below, or a group OR.sub.29 where R.sub.29 represents a protective group for a hydroxyl function, R.sub.25 represents a hydrogen atom, a group of formula (IX) below, or a group OR.sub.29 where R.sub.29 represents a protective group for a hydroxyl function, R.sub.26 represents a group of formula (IX) below, or a group OR.sub.29, where R.sub.29 represents a protective group for a hydroxyl function, and R represents a furan nucleus, optionally substitutable, at least one substituent among R.sub.21, R.sub.22, R.sub.23, R.sub.24, R.sub.25, R.sub.26, R.sub.28, R.sub.21, R.sub.22 or R.sub.23 representing a group of formula (IX) below, said group of formula (IX) being chosen from the groups: ##STR00057## or a salt thereof.

Description

[0188] The features and advantages of the invention will emerge more clearly in light of the implementation examples below, provided simply by way of illustration and which are in no way limiting with respect to the invention, with the support of FIGS. 1 to 9b, wherein:

[0189] FIG. 1 shows the MS(+) mass spectrum of a compound having epoxide functions according to the invention, synthesized by epoxidation of a compound obtained by depolymerization of condensed tannins from white seeds using furan;

[0190] FIG. 2 shows the .sup.1H NMR spectrum of the compound of FIG. 1;

[0191] FIG. 3 shows the .sup.13C NMR spectrum of the compound of FIG. 1;

[0192] FIG. 4 shows the MS(+) mass spectrum of a compound having epoxide functions according to the invention, synthesized by epoxidation of a compound obtained by depolymerization of condensed tannins from white seeds using sylvan;

[0193] FIG. 5 shows a photograph of a sample of epoxy resin formulated from a compound having epoxide functions according to the invention as epoxide prepolymer and from isophorone diamine as curing agent;

[0194] FIG. 6 represents curves illustrating the change in the elastic modulus and in the tan parameter as a function of the stress frequency, of a test sample of an epoxy resin formulated from a compound having epoxide functions according to the invention as epoxide prepolymer and from isophorone diamine as curing agent;

[0195] FIG. 7 shows the MS(+) mass spectrum of a compound having amine functions according to the invention, synthesized by derivatization by addition of cysteamine of a compound having one or more epoxide function(s) according to the invention, itself synthesized by epoxidation of a compound obtained by depolymerization of condensed tannins from white seeds using sylvan;

[0196] FIG. 8 shows the MS(+) mass spectrum of a compound having amine functions according to the invention, synthesized by derivatization by addition of ammonia of a compound having one or more epoxide function(s) according to the invention, itself synthesized by epoxidation of a compound obtained by depolymerization of condensed tannins from white seeds using sylvan; and

[0197] FIGS. 9a and 9b show images of an epoxy resin in accordance with the invention obtained, respectively, after deformation (1 min at 90 C., then cooling under deforming stress) for FIG. 9a, and after heating (1 min at 90 C., then return to ambient temperature without stress), for FIG. 9b.

A. SYNTHESIS OF COMPOUNDS HAVING EPOXIDE FUNCTIONS IN ACCORDANCE WITH THE INVENTION

[0198] Compounds having epoxide functions in accordance with the invention are prepared by glycidylation of the products of depolymerization of condensed tannins either using furan (of formula (VIIa) above), or using sylvan (of formula (VIIb) above). The condensed tannins are used in the form of industrial seed extracts produced from marcs originating from white wine productions (white seed tannins) (high quality grade), obtained from the Union des Distilleries de la Meditrrane [Mediterranean Union of Distilleries].

[0199] A.1. Depolymerization of Condensed Tannins Using Furan

[0200] The white seed tannin extract (5.0 g) is dissolved in MeOH (200 ml), in a bottle, then furan (108 ml) is added, followed by hydrochloric methanol (83 ml of fuming HCl in 108 ml of MeOH) without stirring. The mixture is brought to 40 C., for 30 min, and then cooled to 0 C. 500 ml of an aqueous Na.sub.2CO.sub.3 solution (106 g.Math.l.sup.1) are then added. The mixture is extracted with ethyl acetate (EtOAc) (3400 ml), then subjected to evaporation. A pasty brown-black solid (3.34 g) is obtained, which is taken up in diethyl ether (Et.sub.2O) (200 ml), triturated and sonicated, then washed with brine (300 ml). These operations are repeated twice, and the solutions obtained are dried (Na.sub.2SO.sub.4) and then evaporated so as to obtain a brownish pasty solid (2.40 g), which consists of a mixture of furylated extension units and terminal units below: [0201] furylated extension units corresponding to general formula (V) above:

##STR00027## [0202] terminal units:

##STR00028##

[0203] where Gal represents a gallate group of formula (VI) defined above.

[0204] A.2. Glycidylation of the Products Obtained by Depolymerization of Condensed Tannins Using Furan (A.1)

[0205] The products derived from the depolymerization of the tannins with furan (2.40 g) are dissolved in epichlorohydrin (20 ml), and benzyltriethylammonium chloride is added (154 mg). The reaction continues for 1 h at 100 C. An aqueous sodium hydroxide solution (aqueous NaOH, 20% by weight) is added (27 ml), as is additional benzyltriethylammonium chloride (308 mg). The reaction continues for 1 h 30 at 30 C.

[0206] The product is then extracted with ethyl acetate (350 ml), dried and evaporated. A yellow-orange oil is obtained which is triturated from hexane so as to remove the remaining traces of epichlorohydrin. The oil obtained is then deposited on silica gel and eluted with pure ethyl acetate, to give, after evaporation, a yellow oil (2.77 g), referred to as Ef.

[0207] This oil contains a mixture of compounds having epoxide functions of formula (Ic) below:

##STR00029##

[0208] The compounds which go to making up this oil are characterized by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) analysis. This analysis consists in performing a separation of the depolymerization reaction products by ultra performance liquid chromatography (Waters UPLC system) coupled in series to a diode array detector (DAD) and to a mass spectrometer (Brucker AmaZonX model) (UPLC-MS). The synthesis samples are analyzed extemporaneously, the product being diluted where appropriate for a final concentration of 1 g.Math.l.sup.1. The samples (2 l) are injected onto a Waters Acquity Atlantis HSS T3 1.8 m-2.1100 mm column, and eluted with the solvents A (99:1 H.sub.2O:HCOOH) and B (19:1:80 H.sub.2O:HCOOH:MeCN) according to the A/B gradient: 99% to 1% linear, 8 min; 1% isocratic, 1 min; 1% to 99% linear, 1 min; for a flow rate of 550 l.Math.min.sup.1. The UV chromatogram recorded at 280 nm allows phenolic derivatives to be analyzed. The MS(+) chromatogram allows the products to be identified on the basis of the m/z values.

[0209] The compounds having epoxide functions of catechin-furan type, corresponding to general formula (Ii):

##STR00030##

[0210] are purified by chromatography for formal characterization by .sup.1H NMR and .sup.13C NMR spectrometry and by mass spectrometry.

[0211] The purification is carried out by flash chromatography on an Interchim PF430 instrument and by solid deposit on 15 m silica gel, with a 0.fwdarw.100% EtOAc/heptane gradient. The fractions of interest are collected and evaporated to dryness under vacuum.

[0212] The acquisition of the NMR spectra is carried out on spectrometers at 400 MHz and 600 MHz (Brucker). The samples are dissolved in DMSO-d6. The spectra are obtained at 25 C. and the chemical shifts are given in parts per millions (ppm). The assignment of the signals (protons and carbons) is done by choosing as internal reference the chemical shifts of the DMSO-d6, that is to say 2.5 ppm for .sup.1H and 39.5 ppm for .sup.13C. Other than the 1D experiments (.sup.1H and .sup.13C), the interpretations of structures are carried out by means of HSQC and HMBC two-dimensional NMR experiments.

[0213] By way of example, the spectra obtained for the particular compound of general formula (Ii):

##STR00031##

[0214] are shown, respectively, in FIG. 1 for the mass spectrum (M+H.sup.+)/z=581, in FIG. 2 for the .sup.1H NMR spectrum and in FIG. 3 for the .sup.13C NMR spectrum (in DMSO-d6). These spectra confirm the structure of the compound (Ii) in accordance with the invention above, as shown in Table 1 below which summarizes the NMR data obtained.

TABLE-US-00001 TABLE 1 NMR characterization of the compound having epoxide functions (Ii) in accordance with the invention - m, d and dd signify respectively multiplet, doublet and doublet of doublets. Assignment .sup.13C (ppm) Type .sup.1H (ppm) Coupling J 1 74.6 CH 4.80 d - 7.3 Hz 2 67.8 CH 4.05 m 3 39.1 CH 4.20 m 4 101.4 Q 5 155.4 Q 6 94.4 CH 6.19 d - 2.2 Hz 7-9 158.5-158.2-158.1 Q 17-18 8 93.3 CH 6.24 d - 2.2 Hz 10 156.1 Q 11 106.7 CH 5.88 d - 3.1 Hz 12 110.5 CH 6.37 dd - 1.8/3.1 Hz 13 141.7 CH 7.58 d - 1.8 Hz 14 132.0 Q 15 120.2 CH 6.91 dd - 2.0/8.4 Hz 16 113.6 CH 6.98 d - 8.4 Hz 19 113.6 CH 7.04 d - 2.0 Hz 20-23 70.1-69.9 CH.sub.2 4.30-3.83 m 27-30 21-24 49.8 CH 3.33 m 28-31 22-25 43.7 CH.sub.2 2.72 m 29-32 43.4 2.84 26 OH 5.31 d - 4.6 Hz

[0215] The spectra obtained for the particular compound of general formula (Ii):

##STR00032##

[0216] make it possible to obtain the NMR data indicated in Table 2 below.

TABLE-US-00002 TABLE 2 NMR characterization of the compound having epoxide functions (Ii) in accordance with the invention - m, d and dd signify respectively multiplet, doublet and double of doublets. Assignment .sup.13C (ppm) Type .sup.1H (ppm) Coupling J 1 74.5 CH 4.74 m 2 67.9 CH 4.00 m 3 39.2 CH 4.17 m 4 101.4 Q 5 155.5 Q 6 94.4 CH 6.17 d - 2.1 Hz 7-9 158.5 Q 8 93.2 CH 6.22 d - 2.1 Hz 10 156.1 Q 11 106.7 CH 5.86 d - 3.0 Hz 12 110.4 CH 6.35 dd - 2.0/3.0 Hz 13 141.7 CH 7.55 d - 2.0 Hz 14 132.0 Q 15 119.5 CH 6.75 m 16 116.3 CH 6.81 m 17-18 142.5 Q 19 116.0 CH 6.91 m 20 65.2 CH.sub.2 4.30-3.97 m 21 73.7 CH 4.13 m 22 59.9 CH.sub.2 3.61 m 23 OH 5.03 m 24 OH 5.29 m 25-28 69.0 CH.sub.2 4.29-3.79 m 26-29 49.6 CH 3.03 m 27-30 43.4 CH.sub.2 2.72-2.53 dd - 4.2/5.1 Hz + dd - 43.7 2.83-2.68 2.5/5.1 Hz dd - 4.2/5.1 Hz + m

[0217] These data confirm the structure of the compound (Ii) in accordance with the invention above.

[0218] A.3. Depolymerization of Condensed Tannins Using Sylvan

[0219] In a round-bottomed flask, the white seed tannin extract (8.0 g) is dissolved in MeOH (300 ml), then the sylvan (100 ml) followed gently by the fuming HCl (3.33 ml) are added, with stirring. The mixture is brought to 30 C. for 60 min. 400 ml of an aqueous Na.sub.2CO.sub.3 solution are added (5.3 g.Math.l.sup.1), then an extraction with EtOAc (3400 ml) is carried out. The solution is evaporated to give a pasty brownish solid (5.7 g), which is taken up with Et.sub.2O (200 ml), triturated and sonicated, then washed with brine (300 ml). These operations are repeated twice, and the resulting solutions are combined, and dried with Na.sub.2SO.sub.4. The solution is evaporated so as to obtain a beige bullate solid (2.40 g), consisting of a mixture of sylvanylated extension units and terminal units below: [0220] sylvanylated extension units corresponding to general formula (V) above:

##STR00033## [0221] terminal units:

##STR00034##

[0222] where Gal represents a gallate group of formula (VI) defined above.

[0223] A.4. Glycidylation of the Products Obtained by Depolymerization of Condensed Tannins Using Sylvan (A.3)

[0224] The products resulting from the depolymerization of the tannins using sylvan (9.00 g) are dissolved in epichlorohydrin (98 ml), and benzyltriethylammonium chloride is added (707 mg). The reaction continues for 1 h at 100 C. In a second step, an aqueous sodium hydroxide solution (aqueous NaOH, 20% by weight) is added (124 ml), as is additional benzyltriethylammonium chloride (1.41 g). The reaction continues for 1 h 30 at 30 C. The product is then extracted with ethyl acetate (3200 ml), dried and evaporated. A brown oil is obtained which is triturated from hexane in order to remove the remaining traces of epichlorohydrin. The oil obtained is then deposited on silica gel and eluted with pure ethyl acetate to give, after evaporation, an orange oil (16.0 g), referred to as Es.

[0225] This oil contains a mixture of compounds having epoxide functions of formula (Id) below:

##STR00035##

[0226] The compounds which go to make up this oil are characterized by ultra-high performance liquid chromatography-mass spectrometry (UPLC-MS) analysis, as described above.

[0227] The compounds having epoxide functions of catechin-sylvan type, correspond to general formula (Ij):

##STR00036##

[0228] are purified for formal characterization by .sup.1H NMR and .sup.13C NMR spectrometry and by mass spectrometry, as described above.

[0229] By way of example, the mass spectrum (M+H.sup.+)/z=595 obtained for the particular compound of general formula (Ij):

##STR00037##

[0230] is show in FIG. 4.

[0231] The .sup.1H NMR and .sup.13C NMR spectra also carried out make it possible to obtain NMR data indicated in Table 3 below.

TABLE-US-00003 TABLE 3 NMR characterization of the compound having epoxide functions (Ij) in accordance with the invention - m, d and bs signify respectively multiplet, doublet and broad singlet. Assignment .sup.13C (ppm) type .sup.1H (ppm) Coupling J 1 74.6 CH 4.83 d - 8.8 Hz 2 67.9 CH 4.03 m 3 38.6 CH 4.11 m 4 101.6 Q 5 155.5 Q 6 94.5 CH 6.17 m 7 & 9 158.5 Q 158.1 8 93.2 CH 6.23 m 10 154.6 Q 11 107.4 CH 5.70 m 12 106.5 CH 5.94 m 13 150.1 CH 14 132.1 Q 15 120.3 CH 6.92 m 16 113.7 CH 6.98 d - 8.3 Hz 17 & 18 147.7 Q 147.6 19 113.7 CH 7.05 m 20-23 70.1-69.9 CH.sub.2 4.30-3.84 m 27-30 21-24 49.9-49.7 CH 3.32 m 28-31 22-25 43.7-43.4 CH.sub.2 2.83-2.70 m 29-32 26 OH 5.27 bs 33 13.1 CH.sub.3 2.24 m

[0232] These data, and also the mass spectrum obtained, confirm the structure of the compound (Ij) in accordance with the invention above.

[0233] A.5. Assaying of the Epoxide Functions of the Compounds Synthesized

[0234] The assaying of the epoxide functions makes it possible to obtain the EEW epoxide index.

[0235] Principle of the Assay

[0236] The objective of the assay is to open the epoxide ring under acid conditions and to determine the amount of acid having reacted, and therefore the amount of epoxide functions present.

[0237] The product to be analyzed is weighed exactly (approximately 100 mg) and dissolved in 13 ml of a 0.2 M solution of HCl in pyridine. The reaction medium is then heated at 120 C. for 20 min and then brought back to ambient temperature. The colorimetric assay of the excess acid is carried out with an exactly titrated solution of sodium hydroxide in methanol (approximately 6 to 7 mmol.Math.l.sup.1), in the presence of phenolphthalein. The assay is carried out in triplicate for each product. The 0.2 M HCl solution is also assayed with sodium hydroxide (blank).

[0238] The epoxide index is calculated according to the following equation, for a given weight of prepolymer w.sub.epoxide, a known sodium hydroxide concentration C.sub.NaoH and volumes of sodium hydroxide V.sub.0 for the blank (acid without epoxide) and V.sub.epoxide for the excess acid after reaction with the prepolymer:

[00002]$\mathrm{EEW}=\frac{w_{\mathrm{epoxide}}}{\left(V_0-V_{\mathrm{epoxide}}\right).Math.C_{\mathrm{NaOH}}}$

[0239] Experimental Results

[0240] DGEBA (Diglycidyl Ether of Bisphenol A) Reference Assay

[0241] Theoretical value (calculated): the molecular weight of DGEBA is 340 g.Math.mol.sup.1 and the structure contains two epoxide functions, that is to say an EEW.sub.th equal to 170 g.Math.mol.sup.1 of epoxide.

[0242] Experimental value (obtained by assaying): EEW=165 g.Math.mol.sup.1 of epoxide, that is to say a difference of 3% with the theoretical value, confirming the reliability of the assay method. [0243] Assaying of the oil Ef (products resulting from the glycidylation of the industrial extract of grape seed tannins depolymerized in the presence of furan):

EEW.sub.exp=116 g.Math.mol.sup.1 [0244] Assaying of the oil Es (products resulting from the glycidylation of the industrial extract of grape seed tannins depolymerized in the presence of sylvan):

EEW.sub.exp=133 g.Math.mol.sup.1

[0245] The values of these EEW indices are lower than that of DGEBA and conform to the UPLC-MS analyses indicating a high degree of glycidylation.

B. METHOD FOR PRODUCING EPOXY RESINS IN ACCORDANCE WITH THE INVENTION

[0246] A method for producing an epoxy resin in accordance with the invention involves the mixing of a compound having one or more epoxide function(s) according to the invention, as epoxide prepolymer, with a curing agent of polyamine type, more specifically with a stoichiometric molar ratio of amine active H per epoxide function.

[0247] The curing agent used is isophorone diamine, which comprises two primary amine functions, that is to say 4 active H per mole of curing agent.

[0248] B.1. Starting from the Oil Ef

[0249] The oil Ef obtained by oxidation of the reaction crude of the depolymerization of condensed tannins using furan (EEW=116 g.Math.l.sup.1) is used to produce an epoxy resin, as follows.

[0250] 950 mg of oil Ef and 372 l of isophorone diamine are mixed so as to prepare a homogeneous mixture. The mixture is cast into a test specimen and heated at 90 C. for 20 min. A disk of hard yellow translucent resin is obtained, an image of which is shown in FIG. 5.

[0251] B.2. Starting from the Oil Es

[0252] The oil Es obtained by epoxidation of the reaction crude of the depolymerization of condensed tannins using sylvane (EEW=133 g.Math.l.sup.1) is used to produce an epoxy resin, as follows.

[0253] 1.1 g of oil Ef and 377 l of isophorone diamine are mixed so as to produce a homogeneous mixture. The mixture is cast into a test specimen and heated at 90 C. for 30 min under pressure (200 bar). A test specimen 6.24 mm long, 5.28 mm wide and 0.98 mm thick, of hard yellow translucent resin is obtained. The appearance of this resin is similar to that shown in FIG. 5.

[0254] A study of the mechanical strength of this epoxy resin was carried out by dynamic mechanical analysis (DMA) at 25 C. of the resin test specimen obtained, by means of a TA Instruments DMA 2980 analyzer. The DMA measurement conditions are the following: scan of 0.6 to 300 Hz for a deformation of 0.05 mm, at 25 C. The curves obtained, representing the elastic modulus and the tan factor as a function of the stress frequency, are shown in FIG. 6. It is deduced therefrom that the characteristics of the epoxy resin according to the invention are those of a hard material, with a tan damping factor of 310.sup.2, that is to say in the range of those of Plexiglas, of concrete and of brick, and with an elastic modulus of 0.43 GPa.

C. PRODUCTION OF POLYAMINE CURING AGENTS IN ACCORDANCE WITH THE INVENTION

[0255] Polyamine curing agents in accordance with the invention are produced from, respectively, the oils Ef and Es obtained as indicated above, according to the protocols below.

[0256] C.1. Derivatization by Addition of Cysteamine

[0257] 1.0 g of oil (Ef or Es) is dissolved in MeOH (50 ml). Cysteamine hydrochloride is added (3.8 g), followed by N,N-diisopropylethylamine (2.9 ml). The reaction is left to take place for 20 h at ambient temperature. Sodium carbonate is added (8.3 g), and then the MeOH is evaporated off. The product is extracted by trituration of the residue from acetone (350 ml). The three organic phases are combined, dried, and evaporated to give an orangey oil.

[0258] Starting from the oil Es, a mixture of compounds of general formula (VIIIc) below is obtained, and starting from the oil Ef, a mixture of compounds of general formula (VIIId) above is obtained, with, for these two formulae, a group (IX) which can correspond to the formulae:

##STR00038##

[0259] Compounds having particular amine functions thus obtained are derivatives of catechin, and correspond to general formulae (VIIIe) and (VIIIf) below:

##STR00039##

[0260] wherein the group of formula (IX) can correspond to the formulae:

##STR00040##

[0261] Compounds of the invention thus obtained, which are particularly advantageous for use as curing agents, since they bear four primary amine functions, each being able to react with two epoxide functions, correspond to general formula (VIIIg):

##STR00041##

[0262] wherein R.sub.z represents a hydrogen atom or a methyl radical.

[0263] By way of example, FIG. 7 shows the mass spectrum obtained for the compound according to the invention of general formula (VIIIg) above, wherein Rz represents a methyl radical: (M+H.sup.+)/z=903 with z=1, (M+2H.sup.+)/z=452 with z=2, (M+3H.sup.+)/z=302 with z=3.

[0264] C.2. Derivatization by Addition of Aqueous Ammonia

[0265] In a pressure-resistant threaded flask, the oil (1.0 g) is dissolved in isopropanol (iPrOH) (67 ml). Aqueous ammonia (aqueous NH.sub.3, 25%) is added (33 ml). The tube is hermetically stoppered with a stopper which has a PTFE septum, and brought to 85 C. with stirring for 6 h. The aqueous ammonia and the iPrOH are then evaporated to dryness so as to directly give the expected product in the form of a viscous yellow-orange oil (1.2 g; quantitative yield).

[0266] Starting from the oil Es, a mixture of compounds of general formula (VIIIc) above is obtained, and starting from the oil Ef, a mixture of compounds of general formula (VIIId) above is obtained, with, for these two formulae, a group (IX) which can correspond to the formulae:

##STR00042##

[0267] Particular compounds having amine functions thus obtained are catechin derivatives, and correspond to general formulae (VIIIk) and (VIIIm) below:

##STR00043##

[0268] wherein the group of formula (IX) can correspond to the formulae:

##STR00044##

[0269] Compounds of the invention thus obtained that are particularly advantageous for use as curing agents, since they bear four primary amine functions, each being able to react with two epoxide functions, correspond to general formula (VIIIn):

##STR00045##

[0270] wherein R.sub.z represents a hydrogen atom or a methyl radical.

[0271] The structures of all of the compounds having one or more amine function(s) according to the invention that are obtained as indicated above were confirmed by mass spectrometry and NMR spectrometry analysis. By way of example, FIG. 8 shows the mass spectrum obtained for the compound according to the invention of general formula (VIIIn) above, wherein Rz is a hydrogen atom: (M+H.sup.+)/z=649 with z=1, (M+2H.sup.+)/z=325 with z=2, (M+3H.sup.+)/z=217 with z=3.

[0272] The NMR spectra obtained for the compound of general formula (VIIIo) according to the invention below:

##STR00046##

[0273] make it possible to obtain the NMR data indicated in Table 4 below.

TABLE-US-00004 TABLE 4 NMR characterization of the compound having epoxide functions (VIIIo) in accordance with the invention - m, d and s signify respectively multiplet, doublet and singlet Assignment .sup.13C (ppm) Type .sup.1H (ppm) Coupling J 1 74.1 CH 4.79 m 2 67.7 CH 3.97 m 3 38.5 CH 4.11 m 4 101.0 Q 5 155.2 Q 6 93.8 CH 6.11 d - 2.6 Hz 7 158.7 Q 8 92.4 CH 6.15 d - 2.6 Hz 9 158.3 Q 10 154.5 Q 11 105.9 CH 5.92 12 106.9 CH 5.69 13 149.7 Q 14 13.1 CH.sub.3 2.23 s 15 132.0 Q 16 119.4 CH 6.78 m 17 115.9 CH 6.83 m 18 142.2 Q 19 142.2 Q m 20 115.5 CH 6.94 m 21 64.7 CH.sub.2 4.31-4.01 m 22 71.7 CH 4.31 m 23 69.0 CH.sub.2 3.65 m 24 73.4 CH.sub.2 3.42-3.39 m 25 70.3 CH 3.52 m 26 44.4 CH.sub.2 2.59-2.46 m 27 70.0 CH.sub.2 3.92-3.83 m 28 70.0 CH 3.71 m 29 44.5 CH.sub.2 2.69-2.58 m 30 69.5 CH.sub.2 3.81-3.71 m 31 69.9 CH 3.59 m 32 44.3 CH.sub.2 2.50-2.35 m

[0274] These data confirm the structure of the compound (VIIIo) in accordance with the invention above.

D. EXAMPLES OF SYNTHESIS OF EPOXY RESINS IN ACCORDANCE WITH THE INVENTION

[0275] Epoxy resins are produced according to various methods in accordance with the present invention, in the following way.

[0276] D.1 Synthesis of a Material from the Prepolymer Es with the Octylamine Curing Agent

[0277] 142 mg of curing agent are dissolved in 222 mg of oil Es. The mixture is brought to 90 C. for 60 min. A hard translucent resin is obtained.

[0278] D.2. Synthesis of a Material from the Prepolymer Es with the Diethylamine Curing Agent

[0279] 103 mg of curing agent are dissolved in 103 mg of oil Es. The mixture is brought to 90 C. for 20 min. A shape-memory translucent resin is obtained.

[0280] D.3. Synthesis of a Material from the Prepolymer Es with Piperidine

[0281] 151 mg of piperidine are dissolved in 230 mg of oil Es. The mixture is brought to 90 C. for 20 min. A resin with thermoplastic properties, which becomes liquid again under hot conditions (90 C.), is obtained.

[0282] D.4. Synthesis of a Material from the Prepolymer Es with the Triethylamine Curing Agent

[0283] 108 mg of curing agent are dissolved in 137 mg of oil Es. The mixture is brought to 90 C. for 20 min. A hard translucent resin is obtained.

[0284] D.5. Synthesis of a Material from the Prepolymer Es with the Pyridine Curing Agent

[0285] 113 mg of curing agent are dissolved in 183 mg of oil Es. The mixture is brought to 90 C. for 20 min. A hard opaque resin which is very dark red in color is obtained.

[0286] D.6. Synthesis of a Material from the Prepolymer Es with the Ethanolamine Curing Agent

[0287] 71 mg of curing agent are dissolved in 299 mg of oil Es. The mixture is brought to 90 C. for 20 min. A shape-memory resin is obtained.

[0288] D.7. Synthesis of a Material from the Prepolymer Es with the Pyrrolidine Curing Agent

[0289] 72 mg of curing agent are dissolved in 150 mg of oil Es. The mixture is brought to 90 C. for 20 min. A hard resin is obtained.

[0290] D.8. Synthesis of a Material from the Commercial Prepolymer DGEBA with the Curing Agent-Sylv-NH.sub.3 (Obtained as Described in C.2.)

[0291] 99 mg of curing agent are dissolved in 99 mg of ethylene glycol. 120 mg of DGEBA are added. The mixture is brought to 90 C. for 20 min. A hard translucent resin is obtained.

[0292] D.9. Synthesis of a Material from the Prepolymer (Es) with the Curing Agent Obtained by Derivatization, by Addition of Aqueous Ammonia, of the Oil Ef (as Described in C.2.)

[0293] 98 mg of curing agent are dissolved in 98 mg of ethylene glycol. 118 mg of oil Es are added. The mixture is brought to 90 C. for 20 min. A hard resin is obtained.

[0294] D.10. Synthesis of a Material from the Prepolymer (Es) with the Curing Agent Obtained by Derivatization, by Addition of Aqueous Ammonia, of the Oil Es (as Described in C.2/)

[0295] 101 mg of curing agent are dissolved in 101 mg of ethylene glycol. 94 mg of oil Es are added. The mixture is brought to 90 C. for 20 min. A hard translucent resin is obtained.

[0296] D.11. Synthesis of a Material from the Prepolymer (Es) with the Curing Agent Obtained by Derivatization, by Addition of Cysteamine, of the Oil Es (as Described in C.1/).

[0297] 93 mg of curing agent are dissolved in 93 mg of ethylene glycol. 115 mg of oil Es are added. The mixture is brought to 90 C. for 20 min. A hard resin is obtained.

[0298] D.12. Synthesis of a Material from the Prepolymer (Es) with, as Curing Agent, the Polyphenols Resulting from the Depolymerization of Tannins with Sylvan (Obtained as Described in A.3/)

[0299] 56 mg of curing agent are dissolved in 123 mg of oil Es. The mixture is brought to 90 C. for 20 min. A hard translucent resin is obtained.

[0300] D.13. Synthesis of a Material from the Prepolymer (Es) with, as Curing Agent, a Furan Derivative, Furfurylamine

[0301] 3.52 g of curing agent are dissolved in 1.28 g of oil Es. The mixture is left at ambient temperature for 16 h, and then brought to 90 C. for 20 min. A resin which has viscoelastic properties is obtained: it is possible to push the nails into said resin, and the marks left by said nails disappear in a few instants.

E. SYNTHESIS OF SHAPE-MEMORY RESINS IN ACCORDANCE WITH THE INVENTION

[0302] The prepolymer Es (1 g) is mixed with diethylamine (1 g).

[0303] The mixture is poured into a pyramidal silicone mold, and cured at 90 C. for 1 h, and then the mold is left to cool to ambient temperature.

[0304] After removal from the mold, a hard object is obtained. When the object is reheated at 90 C., it becomes soft, and it is possible to force it to adopt another shape, which is preserved if the object is cooled to ambient temperature. If the object is again brought to 90 C., it softens again, and adopts the shape that it had at the time of the initial molding.

[0305] FIGS. 9a and 9b illustrate, respectively, the resin obtained: after deformation (1 min at 90 C., then cooling under deforming stress), demonstrating the maintaining of the deformation applied; and after heating (1 min at 90 C., then return to ambient temperature without stress), demonstrating the return to the initial pyramidal shape.