Polyepoxidized biphenyl compounds, preparation and uses

Abstract

A multi-epoxidized biphenyl compound has the formula (I) below ##STR00001##
wherein R, R.sub.1, R.sub.2 and R.sub.3 are as defined in the description, as well as mixtures of at least two of the compounds. These multi-epoxidized biphenyl compounds are fully suitable as main constituents of thermosetting epoxy resins, i.e. as polyepoxides precursors. They are beneficial substitutes for bisphenol A diglycidyl ether.

Claims

1. A compound selected from the group consisting of: (1) a compound of formula (I): ##STR00060## wherein: R is —O-Alk, where Alk is a linear or branched alkyl group having 1 to 6 carbon atoms, R.sub.3 is —O—Z where Z is a linear or branched alkyl group containing 2 to 8 carbon atoms and containing an epoxy function, or R.sub.3 is —O-Alk′ where Alk′ is a linear or branched alkyl group containing 1 to 6 carbon atoms; when R.sub.3 is —O—Z: either R.sub.1 and R.sub.2, which may be the same or different, are independently selected from —CH.sub.2—OH and —CH.sub.2—O—Z; or R.sub.1 and R.sub.2, which may be the same or different, are independently selected from —OH and —O—Z; or R.sub.1 and R.sub.2, which may be the same or different, are independently selected from —COOH and —COO—Z, when R.sub.3=—O-Alk′: R.sub.1 and R.sub.2 are identical and are selected from the group consisting of: —CH.sub.2—O—Z, —O—Z, —COO—Z, —CH.sub.2-epoxy, and ##STR00061## Z being as defined above; and (2) a mixture of at least two compounds of formula (I).

2. The compound of claim 1, wherein R.sub.3 is —O—Z, and Z is a linear alkyl group containing 2 to 8 carbon atoms and an epoxy function.

3. The compound of claim 1, wherein the epoxy function is located at the end of the alkyl chain.

4. The compound of claim 1, wherein R.sub.3 is —O—[CH.sub.2—].sub.n-epoxy, where n is an integer from 0 to 6.

5. The compound of claim 4, wherein n is an integer from 1 to 6.

6. The compound of claim 4, wherein 1≤n≤4.

7. The compound of claim 1, wherein R.sub.3 is —OAlk′, and R.sub.1 and R.sub.2 are identical and are selected from the group consisting of: —CH.sub.2—O—Z, —O—Z and —COO—Z, where Z is a linear alkyl group containing 2 to 8 carbon atoms and an epoxy function.

8. The compound of claim 7, wherein the epoxy function is located at the end of the alkyl chain.

9. The compound of claim 7, wherein R.sub.1 and R.sub.2 are identical and are selected from the group consisting of: —CH.sub.2—O—[CH.sub.2—].sub.n-epoxy, —O—[CH.sub.2—].sub.n-epoxy or —COO—[CH.sub.2].sub.n-epoxy, where n is an integer from 0 to 6.

10. The compound of claim 9, wherein R.sub.1 and R.sub.2 are each —CH.sub.2O—CH.sub.2-epoxy, —O—CH.sub.2-epoxy or —COO—CH.sub.2-epoxy.

11. The compound of claim 1, wherein R.sub.3 is —O—CH.sub.3.

12. A process for preparing a compound of formula (I) as defined in claim 1, the process comprising the steps of: a) providing a dimer selected from the group consisting of: (i) divanillin, divanillyl alcohol, dimethoxyhydroquinone, divanillic acid, dieugenol and diisoeugenol, said dimers having at least two phenolic —OH functions and two —O—CH.sub.3 functions, and (ii) analogs of said dimers having said at least two phenolic —OH functions and two —O—(C.sub.2-C.sub.6)alkyl functions, b) optionally, alkylating the phenolic —OH functions of the dimer provided in step a) or of an analog thereof, it being understood that the alkylation of divanillin or an analog thereof is followed by oxidation to obtain alkylated di(C.sub.1-C.sub.6)alkoxyhydroquinone; c1) either epoxidizing the phenolic —OH functions of the non-alkylated dimer or analog thereof, or c2) epoxidizing the non-alkylated functions still present on the biphenyl nucleus of the alkylated dimer or analog thereof.

13. The process of claim 12, wherein the epoxidation is carried out: by reaction with a compound of formula Cl—Z, wherein Z is a linear or branched alkyl group containing from 2 to 8 carbon atoms and containing an epoxy function, said compound advantageously, or by allylation and subsequent oxidative epoxidation of the double bonds introduced, or by oxidative epoxidation of at least one double bond present.

14. The process of claim 13 wherein Cl—Z is epichlorohydrin.

15. A thermosetting epoxy resin containing at least one compound of claim 1.

16. A thermoset epoxy resin obtained by heat treatment, in the presence of at least one thermosetting agent, of a thermosetting epoxy resin of claim 15.

17. A compound selected from the group consisting of: the diglycidyl ether of divanillyl alcohol of formula: ##STR00062## the triglycidyl ether of divanillyl alcohol of formula: ##STR00063## the tetraglycidyl ether of divanillyl alcohol of formula: ##STR00064## mixtures of at least two of said glycidyl ethers of divanillyl alcohol, the diglycidyl ether of divanillin of formula: ##STR00065## the diglycidyl ether of dimethoxyhydroquinone of formula: ##STR00066## the triglycidyl ether of dimethoxyhydroquinone of formula: ##STR00067## the tetraglycidyl ether of dimethoxyhydroquinone of formula: ##STR00068## mixtures of at least two of said glycidyl ethers of dimethoxyhydroquinone, the diglycidyl ether of divanillic acid of formula: ##STR00069## the triglycidyl ether of divanillic acid of formula: ##STR00070## the tetraglycidyl ether of divanillic acid of formula: ##STR00071## mixtures of at least two of said glycidyl ethers of divanillic acid, the diglycidyl ether of dieugenol of formula: ##STR00072## the triglycidyl ether of dieugenol of formula: ##STR00073## the tetraglycidyl ether of dieugenol of formula: ##STR00074## mixtures of at least two of said glycidyl ethers of dieugenol, the diglycidyl ether of diisoeugenol of formula: ##STR00075## the triglycidyl ether of diisoeugenol of formula: ##STR00076## the tetraglycidyl ether of diisoeugenol of formula: ##STR00077## mixtures of at least two of said glycidyl ethers of diisoeugenol, the diglycidyl ether of methylated divanillyl alcohol of formula: ##STR00078## the diglycidyl ether of methylated divanillic acid of formula: ##STR00079## the diglycidyl ether of methylated dimethoxyhydroquinone of formula: ##STR00080## the diglycidyl ether of methylated dieugenol of formula: ##STR00081## and the diglycidyl ether of methylated diisoeugenol of formula: ##STR00082##

18. The compound of claim 17, which is selected from the group consisting of: the diglycidyl ether of divanillyl alcohol of formula: ##STR00083## the triglycidyl ether of divanillyl alcohol of formula: ##STR00084## the tetraglycidyl ether of divanillyl alcohol of formula: ##STR00085## and mixtures of at least two of said glycidyl ethers of divanillyl alcohol.

19. A thermosetting epoxy resin containing a compound of claim 18.

20. The compound of claim 17, which is the diglycidyl ether of divanillin of formula: ##STR00086##

21. A thermosetting epoxy resin containing at least one compound of claim 20.

22. The compound of claim 17, selected from the group consisting of: the diglycidyl ether of dimethoxyhydroquinone of formula: ##STR00087## the triglycidyl ether of dimethoxyhydroquinone of formula: ##STR00088## the tetraglycidyl ether of dimethoxyhydroquinone of formula: ##STR00089## and mixtures of at least two of said glycidyl ethers of dimethoxyhydroquinone.

23. A thermosetting epoxy resin containing at least one compound of claim 22.

24. The compound of claim 17, selected from the group consisting of: the diglycidyl ether of divanillic acid of formula: ##STR00090## the triglycidyl ether of divanillic acid of formula: ##STR00091## the tetraglycidyl ether of divanillic acid of formula: ##STR00092## and mixtures of at least two of said glycidyl ethers of divanillic acid.

25. A thermosetting epoxy resin containing at least one compound of claim 24.

26. The compound of claim 17, which is selected from the group consisting of: the diglycidyl ether of dieugenol of formula: ##STR00093## the triglycidyl ether of dieugenol of formula: ##STR00094## the tetraglycidyl ether of dieugenol of formula: ##STR00095## and mixtures of at least two of said glycidyl ethers of dieugenol.

27. A thermosetting epoxy resin containing at least one compound of claim 26.

28. The compound of claim 17, selected from the group consisting of: the diglycidyl ether of diisoeugenol of formula: ##STR00096## the triglycidyl ether of diisoeugenol of formula: ##STR00097## the tetraglycidyl ether of diisoeugenol of formula: ##STR00098## and mixtures of at least two of said glycidyl ethers of diisoeugenol.

29. A thermosetting epoxy resin containing at least one compound of claim 28.

30. The compound of claim 17, selected from the group consisting of: the diglycidyl ether of methylated divanillyl alcohol of formula: ##STR00099## the diglycidyl ether of methylated divanillic acid of formula: ##STR00100## the diglycidyl ether of methylated dimethoxyhydroquinone of formula: ##STR00101## the diglycidyl ether of methylated dieugenol of formula: ##STR00102## and the diglycidyl ether of methylated diisoeugenol of formula: ##STR00103##

31. A thermosetting epoxy resin containing at least one compound of claim 30.

Description

(1) The invention is now illustrated by the following examples and the appended figures.

(2) FIGS. 1A and 1B are diagrams illustrating the process of the invention as described above.

(3) FIG. 2 shows the result of chromatography conducted on a mixture of multi-GEDVAs (see Example 1).

(4) FIGS. 3A to 13A are .sup.1H NMR spectra of compounds (or mixtures of compounds) of the invention prepared in the following examples; FIGS. 3B to 13B are .sup.13C NMR spectra of compounds of the invention prepared in the following examples (however, there is no FIG. 7B).

I. COMPOUNDS OF FORMULA (I), IN WHICH R.SUB.3.=O—CH.SUB.2.-EPOXY, DERIVATIVES OF VANILLIN, METHYL VANILLATE OR EUGENOL (ISOLATED AND/OR AS A MIXTURE)

Example 1

(5) A1. Synthesis of Compounds of Formula (I) from Divanillyl Alcohol (DVA)

(6) The different steps of the reaction scheme below have been successively implemented.

(7) ##STR00029## ##STR00030##
Synthesis of Divanillin (DV)

(8) The preparation of divanillin was carried out according to the procedure described in Example 1 of patent application EP 3 002 333. Specifically, the following procedure was followed.

(9) Vanillin (20 g) (the one used, marketed by the company Acros, was not biosourced. For all intents and purposes, it is indicated that the biosourced vanillin marketed by Borregaard could have been used) was solubilized in acetone (160 mL) and acetate buffer (1.5 L, prepared from 2.63 g acetic acid and 8.4 g sodium acetate). Laccase from Trametes versicolor (170 mg) was added to the resulting mixture. In order to be recycled in active form, said laccase requires oxygen. The reaction medium was therefore left under stirring with constant air bubbling for 24 hours. The divanillin was then recovered by filtration of the buffer solution through a Büchner filter. The filtrate was recovered and reused for further dimerization reactions.

(10) Purification of Synthesized Divanillin (DV)

(11) Traces of vanillin were likely to be present in the recovered divanillin. To remove them, said divanillin was solubilized in an aqueous solution of NaOH (200 mL at 0.5 M; a few drops of 5 M solution were conveniently added to facilitate solubilization). A large volume of ethanol (600 mL) was then added to the solution as well as an aqueous solution of hydrochloric acid (115 mL at 2 M) until pH=3 was reached for the mixture. Both divanillin and vanillin are soluble at basic pH in ethanol. Divanillin, on the other hand, is not soluble in ethanol at acidic pH, unlike vanillin. The addition of acid therefore allows the two products to be separated by precipitation of divanillin.

(12) The resulting product was filtered and dried in an oven to remove all traces of solvent. The synthesis and purification operations were repeated. The yield was approximately 95% each time.

(13) Obtaining divanillin (DV) was confirmed by NMR spectroscopy:

(14) ##STR00031##

(15) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm): δ 9.69 (s, H.sub.7), 7.57 (d, H.sub.1), 7.16 (d, H.sub.5), 3.76 (s, H.sub.8).

(16) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 191.62 (s, C.sub.7), 150.88 (s, C.sub.3), 148.61 (s, C.sub.2), 128.64 (s, C.sub.6), 128.21 (s, C.sub.4), 125.02 (s, C.sub.5), 109.6 (s, C.sub.1), 56.25 (C.sub.8).

(17) Synthesis of Divanillyl Alcohol (DVA)

(18) The preparation of divanillyl alcohol was carried out according to the protocol described in Example 8 of patent application EP 3 002 333. Specifically, the process was as follows.

(19) Purified divanillin (20 g) was reduced with sodium borohydride (NaBH.sub.4) to form divanillyl alcohol. It was solubilized in 0.5 M sodium hydroxide solution (180 mL; a few drops of 5 M solution were conveniently added to facilitate solubilization). Then NaBH.sub.4 (3 g) was added and the mixture was kept under stirring until completely dissolved. After one hour of stirring, the reaction was stopped by adding, dropwise, an aqueous solution of hydrochloric acid (160 mL at 2 M) until pH=3 was reached. The divanillyl alcohol then precipitated. It was recovered by filtration. The recovered product was dried in an oven. Synthesis was repeated. The yield was approximately 80% each time.

(20) Obtaining divanillyl alcohol (DVA) was confirmed by NMR spectroscopy:

(21) ##STR00032##

(22) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 8.22 (s, H.sub.9), 6.88 (d, H.sub.1), 6.67 (d, H.sub.5), 5.01 (t, H.sub.10), 4.41 (d, H.sub.7), 3.82 (s, H.sub.8).

(23) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 147.94 (s, C.sub.3), 142.77 (s, C.sub.2), 133.08 (s, C.sub.6), 125.92 (s, C.sub.4), 121.83 (s, C.sub.5), 109.50 (s, C.sub.1), 63.38 (s, C.sub.7), 56.25 (s, C.sub.8).

(24) Synthesis of Compounds of Formula (I) (Multi-Epoxidized Prepolymers)

(25) The last step consisted of epoxidizing divanillyl alcohol (DVA) with epichlorohydrin and resulted in mixtures of different polyglycidyl ethers of divanillyl alcohol. It was used under different conditions to obtain different mixtures.

(26) The multi-epoxidized compounds that could be obtained and whose presence was confirmed (quantitatively and qualitatively) were those with the formula shown in the above reaction scheme, namely:

(27) diglycidyl ether of divanillyl alcohol (DiGEDVA),

(28) triglycidyl ether of divanillyl alcohol (TriGEDVA), and

(29) tetraglycidyl ether of divanillyl alcohol (TetraGEDVA).

(30) a) The experimental conditions used to obtain a mixture of 25% TriGEDVA and 75% TetraGEDVA (% by mass) are described below.

(31) DVA (20 g) was first mixed with epichlorohydrin (100 mL) and tetrabutylammonium bromide (TEBAC) (2 g). TEBAC is a phase transfer agent that allows phenol to react with epichlorohydrin, introduced in excess to form a di-epoxide. The reaction mixture was left to stir at 80° C. for 1.5 hours and then cooled to room temperature.

(32) Subsequently, an aqueous solution of sodium hydroxide (NaOH) (160 mL at 10 M: 10 NaOH eq./OH) was added. The addition of the base closed the open epoxides but also deprotonated the benzyl alcohols which, in turn, were epoxidized by nucleophilic substitution with epichlorohydrin. The solution was then mechanically stirred for 20 h in a cold-water bath.

(33) At the end of the reaction, dichloromethane (DCM) (300 mL) was added to the reaction medium to precipitate the salts (NaCl). The liquid phases were separated from the reaction medium and the salts rinsed with 100 mL DCM. The liquid phases were collected and the aqueous phase was extracted with 2×50 mL DCM. The individual organic phases were collected and washed with 100 mL water. The organic phase was concentrated using a rotary evaporator and the epichlorohydrin was finally evaporated under vacuum. The yield was quantitative. The proportion of di-, tri-, and tetra-epoxidized compounds was quantified by HPLC (high performance liquid chromatography). The apparatus used was a SpectraSYSTEM®, mounted on a Phenomenex 5μ C18 100A column. The detector used was a SpectraSYSTEM® UV2000 system from Thermo Separation Products. The analyses were performed with an eluent composed of acetonitrile and water in a 50/50 isocratic proportion.

(34) FIG. 2 attached shows the chromatograph obtained.

(35) b) The procedure described in a) above was reproduced (in all respects) but with the addition of an aqueous solution of NaOH (50 mL at 5 M) and with mechanical stirring for only 1 h. A mixture of 80% DiGEDVA, 15% TriGEDVA and 5% TetraGEDVA (% by mass) was then obtained.

(36) c) The procedure described in a) above was repeated (in all respects) but with the addition of an aqueous solution of NaOH (50 mL at 5 M) and with mechanical stirring for only 8 h. A mixture of 35% DiGEDVA, 50% TriGEDVA and 15% TetraGEDVA (% by mass) was then obtained.

(37) In order to obtain, separately, these different compounds of formula (I) (di-, tri- and tetra-epoxidized), a purification step by flash or instantaneous chromatography, on a Grace Reveleris® apparatus, equipped with a silica cartridge and a UV detector, was carried out on the mixtures, using a dichloromethane/methanol solvent gradient from 99/1 to 90/10 (by volume) for 30 minutes.

(38) The identity of said compounds of formula (I) was confirmed by NMR spectroscopy:

(39) ##STR00033##

(40) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 7.0 (d, H.sub.1), 6.71 (d, H.sub.5), 5.16 (t, H.sub.10), 4.47 (d, H.sub.7), 3.88 (m, H.sub.11), 3.83 (s, H.sub.8), 3.74 (m, H.sub.11b), 2.95 (m, H.sub.12), 2.6 (t, H.sub.13), 2.36 (t, H.sub.13b).

(41) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 152.33 (s, C.sub.3), 144.47 (s, C.sub.2), 138.26 (s, C.sub.6), 132.59 (s, C.sub.4), 120.86 (s, C.sub.5), 110.79 (s, C.sub.1), 74.22 (s, C.sub.11), 63.14 (s, C.sub.7), 56.18 (s, C.sub.8), 50.53 (s, C.sub.12), 43.97 (s, C.sub.13).

(42) The spectra are shown in FIGS. 3A and 3B respectively.

(43) ##STR00034##

(44) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 7.01 (d, H.sub.1), 6.75 (d, H.sub.5), 5.18 (t, H.sub.10), 4.47 (d, H.sub.7 H.sub.14), 3.92 (m, H.sub.11), 3.84 (s, H.sub.8), 3.76 (m, H.sub.11b), 3.69 (m, H.sub.15), 3.29 (m, H.sub.15b), 3.14 (m, H.sub.16), 2.97 (m, H.sub.12), 2.72 (m, H.sub.17), 2.6 (m, H.sub.13), 2.5 (m, H.sub.17b), 2.36 (m, H.sub.13b).

(45) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 152.02 (s, C.sub.3′), δ 151.89 (s, C.sub.3), 144.38 (s, C.sub.2′), 143.68 (s, C.sub.2), 138.12 (s, C.sub.6′), 133.39 (s, C.sub.6), 132.06 (s, C.sub.4′), 131.76 (s, C.sub.4), 121.78 (s, C.sub.5′), 120.26 (s, C.sub.5), 111.55 (s, C.sub.1′), 110.46 (s, C.sub.1), 73.85 (s, C.sub.14), 71.81 (s, C.sub.15), 70.79 (s, C.sub.11), 62.67 (s, C.sub.7), 55.90 (s, C.sub.8), 50.42 (s, C.sub.12), 50.16 (s, C.sub.16), 43.42 (s, C.sub.13C.sub.17).

(46) The spectra are shown in FIGS. 4A and 4B respectively.

(47) ##STR00035##

(48) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 7.02 (d, H.sub.1), 6.76 (d, H.sub.5), 4.50 (s, H.sub.14), 3.92 (m, H.sub.11), 3.86 (s, H.sub.8), 3.76 (m, H.sub.11b), 3.70 (m, H.sub.15), 3.28 (m, H.sub.15b), 3.14 (m, H.sub.16), 2.97 (m, H.sub.12), 2.73 (m, H.sub.17), 2.60 (m, H.sub.13), 2.55 (m, H.sub.17b), 2.35 (m, H.sub.13b).

(49) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 152.10 (s, C.sub.3), 144.51 (s, C.sub.2), 133.51 (s, C.sub.6), 131.81 (s, C.sub.4), 121.83 (s, C.sub.5), 111.52 (s, C.sub.1), 73.77 (s, C.sub.14), 71.90 (s, C.sub.15), 63.14 (s, C.sub.11), 55.79 (s, C.sub.8), 50.30 (s, C.sub.12), 50.03 (s, C.sub.16), 43.44 (s, C.sub.13 C.sub.17).

(50) The spectra are shown in FIGS. 5A and 5B respectively.

(51) B1. Polyepoxides Obtained from Said Compounds of Formula (I) (Isolated and/or as a Mixture) (Multi-Epoxidized Prepolymers)

(52) For the polymerization (cross-linking polymerization) of the compounds of the invention obtained in this example (DiGEDVA, TriGEDVA and TetraGEDVA, separately and in a mixture: TriGEDVA (25%)+TetraGEDVA (75% (see above)), diaminodiphenyl sulfone (DDS) was used as hardener. This has the formula:

(53) ##STR00036##

(54) This hardener was used in a stoichiometric ratio: epoxy/amine=2/1 and the reaction was carried out at 180° C. for 2 hours.

(55) The same reaction was carried out with bisphenol A diglycidyl ether (DGEBA; prepolymer of the prior art obtained from bisphenol A (BPA)).

(56) The polyepoxides obtained have been evaluated in particular by their alpha transition temperature (it can be assimilated to a glass transition temperature. It was determined by dynamic mechanical analysis (DMA)), by their residual coke rate after degradation at 900° C. (Char900; determined by thermogravimetric analysis (TGA)) and by their Young's modulus. The results are shown in Table 1 below.

(57) TABLE-US-00001 TABLE 1 Polyepoxide Young's precursor modulus prepolymers Tα (° C.) Char900 (%) (GPa) DGEBA 203 18 1.5 DiGEDVA 206 51 1.5 TriGEDVA 254 49 1.4 TetraGEDVA 312 48 1.8 TriGEDVA (25%) + 280 50 1.4 TetraGEDVA (75%)

(58) The figures in said Table 1 confirm the interest of the compounds of the invention.

(59) The higher aromaticity of the polyepoxides of the invention strengthens their structure and leads to networks with Ta values of 206 to 312° C. and Young's moduli of 1.4 to 1.8 GPa.

(60) The residual mass at 900° C. is about 50% for the polyepoxides of the invention and only 18% for the polyepoxide of the prior art. This is very interesting in so far as a high residual mass value indicates good flame retardant properties of the materials. Flame tests were carried out on various samples to verify this claim. Epoxies obtained from DGEBA, on direct contact with the flame, burn and the combustion increases and spreads rapidly throughout the sample. Conversely, for the epoxies of the invention, combustion stops rapidly due to the formation of a protective layer of coke on the surface of the materials.

Example 2

(61) A2. Synthesis of a Compound of Formula (I) from Divanillin (DV)

(62) The different steps of the reaction scheme below have been successively implemented.

(63) ##STR00037##
Synthesis of Divanillin (DV)

(64) This was done as explained above (according to the protocol in Example 1 of patent application EP 3 002 333).

(65) Synthesis of a Compound of Formula (I) (Multi-Epoxidized Prepolymer): Diglycidyl Ether of Divanillin (DiGEDV)

(66) The aldehyde functions of divanillin were preserved. The OH functions were epoxidized with epichlorohydrin. The procedure was as follows.

(67) 3 g of divanillin (10 mmol) was dissolved in 15 mL of epichlorohydrin. 0.3 g of tetrabutylammonium bromide (TEBAC) (0.95 mmol) was added and the resulting mixture was stirred at 80° C. for 12 h. 8 mL of (5 M) NaOH solution (40 mmol) were then added and the mixture was stirred at room temperature for 1.5 h. The product was finally extracted with dichloromethane and washed with water. Dichloromethane and epichlorohydrin were removed from the organic phase using a rotary evaporator. The yield was 90%. Purification was conveniently carried out by flash chromatography using a dichloromethane/methanol solvent gradient (from 99/1 to 90/10 (by volume) for 30 minutes).

(68) The identity of the compound of formula (I) obtained was confirmed by NMR spectroscopy:

(69) ##STR00038##

(70) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 9.94 (s, H.sub.7), 7.60 (d, H.sub.1), 7.48 (s, H.sub.5), 3.93 (s, H.sub.8), 7.0 (s, H.sub.5), 6.71 (s, H.sub.1), 5.16 (t, H.sub.10), 4.47 (d, H.sub.7), 4.18 (m, H.sub.11), 3.95 (s, H.sub.8), 3.85 (m, H.sub.11b), 2.98 (m, H.sub.12), 2.61 (t, H.sub.13), 2.40 (t, H.sub.13b).

(71) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 191.79 (s, C.sub.7), δ 152.48 (s, C.sub.3), 150.67 (s, C.sub.2), 131.84 (s, C.sub.6), 131.29 (s, C.sub.4), 126.40 (s, C.sub.5), 111.48 (s, C.sub.1), 74.24 (s, C.sub.11), 63.14 (s, C.sub.7), 55.89 (s, C.sub.8), 50.12 (s, C.sub.12), 43.44 (s, C.sub.13).

(72) The spectra are shown in FIGS. 6A and 6B respectively.

(73) B2. Polyepoxide Obtained from Said Compound of Formula (I) (Multi-Epoxidized Prepolymer)

(74) For the polymerization of the compound of the invention obtained in this example (diglycidyl ether of divanillin: DiGEDIV), diaminodiphenyl sulfone (DDS), whose chemical formula has been recalled above, was also used as hardener.

(75) This hardener was used in a stoichiometric ratio: epoxy/amine=2/1 and the reaction was carried out at 180° C. for 2 h.

(76) As above, the glass transition temperature (determined by dynamic mechanical analysis (DMA)) and the residual coke content after degradation at 900° C. (determined by thermogravimetric analysis (TGA)) of the prepared polyepoxide were investigated. The results are shown in Table 2 below.

(77) TABLE-US-00002 TABLE 2 Polyepoxide precursor prepolymer Tα (° C.) Char900 (%) DiGEDV 180 54

(78) The figures in said Table 2 confirm the interest of the compounds of the invention.

Example 3

(79) A3. Synthesis of Compounds of Formula (I) (in a Mixture) from Dimethoxyhydroquinone

(80) The different steps of the reaction scheme below have been successively implemented.

(81) ##STR00039## ##STR00040##
Synthesis of Divanillin (DV)

(82) This was done as explained above (according to the protocol in Example 1 of patent application EP 3 002 333).

(83) Synthesis of Dimethoxyhydroquinone (DMHQ)

(84) 6 mmol of divanillin (≈1 g) was dissolved in 10 mL of NaOH (0.5 M). 7 mmol of sodium percarbonate were then added slowly. The mixture was then stirred at room temperature for 12 h. After stirring, the solution was acidified with an aqueous solution of HCl (2 M) until pH=3 was reached. The aqueous phase was then extracted with ethyl acetate. The organic phases were collected and washed with water and dried over magnesium sulfate (MgSO.sub.4). Ethyl acetate was then removed under vacuum using a rotary evaporator. Further purification was carried out by flash chromatography using a dichloromethane/methanol gradient solvent (from 99/1 to 90/10 (by volume) for 30 minutes). The yield was less than 50%. It should be noted that the synthesis carried out (repeated several times) had not been optimized either for higher yield or for obtaining a pure compound.

(85) The identity of DMHQ was confirmed by NMR spectroscopy:

(86) ##STR00041##

(87) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 8.79 (s, H.sub.8), 7.76 (s, H.sub.9), 6.38 (d, H.sub.1), 6.15 (d, H.sub.5), 3.75 (s, H.sub.7).

(88) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 149.76 (s, C.sub.3), 148.62 (s, C.sub.2), 135.77 (s, C.sub.6), 126.65 (s, C.sub.4), 108.35 (s, C.sub.5), 99.35 (s, C.sub.3), 55.65 (s, C.sub.7).

(89) Synthesis of Compounds of Formula (I) (Multi-Epoxidized Prepolymers): Polyglycidyl Ethers of Dimethoxyhydroquinone

(90) 0.5 g of dimethoxyhydroquinone (as prepared above) was dissolved in 10 mL of epichlorohydrin. 0.05 g of tetrabutylammonium bromide (TEBAC) was added and the resulting mixture was stirred at 80° C. for 20 h. 5 mL of a NaOH solution (5 M) (40 mmol) were then added and the resulting new mixture was stirred at room temperature for 24 h. The resulting mixture was extracted with dichloromethane and washed with water. Dichloromethane and epichlorohydrin were removed from the organic phase using a rotary evaporator. The synthesis used was not optimized.

(91) A mixture of polyglycidyl ethers of dimethoxyhydroquinone was thus obtained, said polyglycidyl ethers present in variable proportions, not evaluated. This mixture was analyzed by .sup.1H NMR spectroscopy. The spectrum obtained is shown in FIG. 7A. This spectrum certainly confirms the presence of several epoxy functions.

(92) B3. Polyepoxide Obtained from Said Compounds of Formula (I) (Multi-Epoxidized Prepolymers)

(93) For the polymerization of the mixture of compounds of the invention obtained in this example, diaminodiphenyl sulfone (DDS), whose chemical formula has been recalled above, was also used as a hardener.

(94) This hardener was used in a stoichiometric ratio: epoxy/amine=2/1. In this example, the polyepoxide was not successively prepared and then analyzed by DMA (for determination of its Tg). It was generated, in small amounts (a few mg), during the implementation of differential scanning calorimetry (DSC), for determination of its Tg.

(95) The rate of residual coke, after degradation at 900° C., determined by thermogravimetric analysis (TGA), was determined on this small amount generated during the DSC analysis. The results are shown in Table 3 below.

(96) TABLE-US-00003 TABLE 3 Polyepoxide precursor prepolymer Tg (° C.) Char900 (%) PolyGEDMHQ 212 41

(97) The figures in said Table 3 confirm the interest of the compounds of the invention.

Example 4

(98) A4. Synthesis of a Compound of Formula (I) from Methyl Vanillate

(99) The different steps of the reaction scheme below have been successively implemented.

(100) ##STR00042## ##STR00043##
Synthesis of Methyl Divanillate

(101) For the preparation of methyl divanillate, starting from methyl vanillate (marketed by Sigma-Aldrich), a procedure has been followed which is very similar to that described for the preparation of divanillin in point A1 above (i.e. according to the procedure described in Example 4 of patent application EP 3 002 333).

(102) Obtaining methyl divanillate was confirmed by NMR spectroscopy:

(103) ##STR00044##

(104) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 9.51 (s, H.sub.8), 7.46 (d, H.sub.1), 7.45 (d, H.sub.5), 3.90 (s, H.sub.7), 3.80 (s, H.sub.10).

(105) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 166.09 (s, C.sub.9), 148.88 (s, C.sub.3), 147.47 (s, C.sub.2), 125.40 (s, C.sub.5), 124.36 (s, C.sub.6), 119.48 (s, C.sub.4), 110.92 (s, C.sub.1), 56.01 (s, C.sub.7), 51.79 (s, C.sub.10).

(106) Synthesis of Divanillic Acid (DVAc)

(107) This saponification was carried out according to the procedure described in Example 13 of patent application EP 3 002 333.

(108) Obtaining divanillic acid (DVAc) was confirmed by NMR spectroscopy:

(109) ##STR00045##

(110) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm): δ 9.39 (s, H.sub.8), 7.45 (d, H.sub.1), 7.41 (d, H.sub.5), 3.89 (s, H.sub.7).

(111) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 167.18 (s, C.sub.9), 148.36 (s, C.sub.3), 147.22 (s, C.sub.2), 125.44 (s, C.sub.6), 124.19 (s, C.sub.4), 120.44 (s, C.sub.5), 111.05 (s, C.sub.1), 55.89 (s, C.sub.7).

(112) Synthesis of a Compound of Formula (I) (Multi-Epoxidized Prepolymer): Tetraglycidyl Ether of Divanillic Acid (TetraGEDVAc)

(113) 0.5 g of divanillic acid was dissolved in 10 mL of epichlorohydrin. 0.05 g of tetrabutylammonium bromide (TEBAC) was added and the resulting mixture was stirred at 80° C. for 2 h. 5 mL of a NaOH solution (5 M) (40 mmol) were then added and the resulting new mixture was stirred at room temperature for 20 h. The product was extracted with dichloromethane and washed with water. Dichloromethane and epichlorohydrin were removed from the organic phase using a rotary evaporator. Tetraglycidyl ether of divanillyl acid was isolated from the reaction mixture by flash chromatography, using a dichloromethane/methanol gradient solvent (from 99/1 to 90/10 (by volume) for 30 minutes). The yield was less than 50%. The implemented synthesis was not optimized.

(114) Obtaining said tetraglycidyl ether of divanillic acid was confirmed by NMR spectroscopy:

(115) ##STR00046##

(116) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 7.63 (d, H.sub.1), 7.50 (d, H.sub.5), 4.65 (d, H.sub.10), 4.15 (m, H.sub.10b), 4.09 (s, H.sub.14), 3.94 (m, H.sub.7), 3.86 (m, H.sub.14b), 3.35 (m, H.sub.11), 2.97 (m, H.sub.13), 2.83 (m, H.sub.12), 2.73 (m, H.sub.15), 2.62 (m, H.sub.12b), 2.38 (m, H.sub.15b).

(117) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 164.94 (s, C.sub.9), 152.12 (s, C.sub.3), 149.56 (s, C.sub.2), 131.23 (s, C.sub.6), 124.57 (s, C.sub.4), 124.18 (s, C.sub.5), 112.98 (s, C.sub.1), 74.01 (s, C.sub.13), 56.08 (s, C.sub.10), 50.24 (s, C.sub.7), 49.94 (s, C.sub.14), 49.04 (s, C.sub.11), 43.90 (s, C.sub.12), 43.36 (s, C.sub.15).

(118) The spectra are shown in FIGS. 8A and 8B respectively.

Example 5

(119) A5. Synthesis of Compounds of Formula (I) from Eugenol

(120) The different steps of the reaction scheme below have been successively implemented.

(121) ##STR00047## ##STR00048##
Synthesis of Dieugenol (DEG)

(122) For the preparation of dieugenol, the procedure is very similar to that described for the preparation of divanillin in point A1 above. This procedure has already been described in Example 7 of patent application EP 3 002 333.

(123) Obtaining dieugenol (DEG) was confirmed by NMR spectroscopy:

(124) ##STR00049##

(125) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 8.16 (s, H.sub.8), 6.73 (d, H.sub.1), 6.52 (d, H.sub.5), 5.93 (m, H.sub.10), 5.05 (m, H.sub.11), 3.79 (s, H.sub.7), 3.27 (d, H.sub.9).

(126) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 147.61 (s, C.sub.2), 141.79 (s, C.sub.3), 138.15 (s, C.sub.10), 129.60 (s, C.sub.6), 125.91 (s, C.sub.4), 122.84 (s, C.sub.5), 115.39 (s, C.sub.11), 110.79 (s, C.sub.1), 55.82 (s, C.sub.7), 39.23 (s, C.sub.9).

(127) Synthesis of a Compound of Formula (I) (Multi-Epoxidized Prepolymer):

(128) Diglycidyl Ether of Dieugenol (DiGEDEG)

(129) 3 g of dieugenol was dissolved in 15 mL of epichlorohydrin. 0.3 g of tetrabutylammonium bromide (TEBAC) (0.95 mmol) was added and the resulting mixture was stirred at 80° C. for 24 h. 8 mL of a NaOH solution (5 M) (40 mmol) were then added and the new resulting mixture was stirred at room temperature for 24 h. The product was extracted with dichloromethane and washed with water. Dichloromethane and epichlorohydrin were removed from the organic phase using a rotary evaporator. The synthesis used was not optimized: the conversion was not total. The product obtained was not pure.

(130) Obtaining diglycidyl ether of dieugenol (DiGEDEG) was confirmed by NMR spectroscopy:

(131) ##STR00050##

(132) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 6.87 (d, H.sub.1), 6.59 (d, H.sub.5), 5.96 (m, H.sub.10), 5.02 (m, H.sub.11), 3.87 (s, H.sub.12), 3.81 (s, H.sub.7), 3.73 (s, H.sub.12b), 3.35 (d, H.sub.9), 2.93 (d, H.sub.13), 2.59 (d, H.sub.14), 2.34 (d, H.sub.14b).

(133) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 151.99 (s, C.sub.2), 143.47 (s, C.sub.3), 137.66 (s, C.sub.10), 135.03 (s, C.sub.6), 132.09 (s, C.sub.4), 122.39 (s, C.sub.5), 115.79 (s, C.sub.11), 112.30 (s, C.sub.1), 73.72 (s, C.sub.12), 55.73 (s, C.sub.7), 50.04 (s, C.sub.13), 43.41 (s, C.sub.14), 39.22 (s, C.sub.9).

(134) The spectra are shown in FIGS. 9A and 9B respectively.

(135) Synthesis of Another Compound of Formula (I) (Multi-Epoxidized Prepolymer): Tetraglycidyl Ether of Dieugenol (TetraGEDEG)

(136) 0.5 g of diglycidyl ether of dieugenol (as obtained above) was dissolved in 7.5 mL of cold DCM. 1 g of mCPBA was solubilized in 7.5 mL of cold DCM and then gradually added to the DiGEDEG solution. The mixture was stirred at room temperature for 24 h. The product was then washed twice with a saturated solution of NaHCO.sub.3 and three times with distilled water. Finally, dichloromethane was removed using a rotary evaporator. Further purification was carried out by flash chromatography using a dichloromethane/methanol gradient solvent (from 99/1 to 90/10 (by volume) for 30 minutes). The yield of this non-optimized synthesis was less than 50%. However, only the tetraglycidyl ether of dieugenol was synthesized (in view of the amount of mCPBA used and the reaction time (24 h) with said mCPBA) and isolated.

(137) Obtaining tetraglycidyl ether of dieugenol was confirmed by NMR spectroscopy:

(138) ##STR00051##

(139) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 6.98 (d, H.sub.1), 6.71 (d, H.sub.5), 3.93 (m, H.sub.12), 3.83 (s, H.sub.7), 3.73 (m, H.sub.12), 3.13 (m, H.sub.10), 2.94 (m, H.sub.13), 2.77 (m, H.sub.9 H.sub.11), 2.60 (m, H.sub.11b H.sub.14), 2.36 (m, H.sub.14b).

(140) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 151.94 (s, C.sub.2), 143.79 (s, C.sub.3), 132.84 (s, C.sub.6), 131.98 (s, C.sub.4), 122.94 (s, C.sub.5), 112.86 (s, C.sub.1), 73.74 (s, C.sub.12), 55.75 (s, C.sub.7), 51.98 (s, C.sub.11), 50.03 (s, C.sub.10), 46.10 (s, C.sub.13), 43.39 (s, C.sub.14), 37.5 (s, C.sub.9.

(141) The spectra are shown in FIGS. 10A and 10B respectively.

(142) B5. Polyepoxide Obtained from the Compound of Formula (I): Diglycidyl Ether of Dieugenol (DiGEDEG) (Multi-Epoxidized Prepolymer)

(143) For the polymerization of the di-epoxidized compound of the invention obtained in this example (diglycidyl ether of dieugenol: DiGEDEG), diaminodiphenyl sulfone (DDS), whose chemical formula has been recalled above, was also used as a hardener.

(144) This hardener was used in a stoichiometric ratio: epoxy/amine=2/1. In this example too, the polyepoxide was not successively prepared and then analyzed by DMA (for determination of its Tg). It was generated, in small amounts (a few mg), during the implementation of differential scanning calorimetry (DSC) for determination of its Tg.

(145) The rate of residual coke, after degradation at 900° C., determined by thermogravimetric analysis (TGA), was determined on this small amount generated during the DSC analysis. The results are shown in Table 4 below.

(146) TABLE-US-00004 TABLE 4 Polyepoxide precursor prepolymer Tg (° C.) Char900 (%) DiGEDEG 144 38

(147) The figures in said Table 4 confirm the interest of the compounds of the invention.

II. COMPOUNDS OF FORMULA (I), IN WHICH R.SUB.3.=O—CH.SUB.3., DERIVED FROM VANILLIN, METHYL VANILLATE OR EUGENOL

Example 6

(148) A6. Synthesis of Compounds of Formula (I) (Multi-Epoxidized Phenolic Compounds) from Methylated Biphenols

(149) Etherification under the conditions explained below has been implemented on the biphenols identified below.

(150) ##STR00052##
Synthesis of Methylated Biphenols

(151) 26 mmol of bisphenol (see below) and 15.2 g of potassium carbonate (110 mmol) were dissolved in 120 mL of DMF. 9.6 mL of iodomethane (158 mmol) were then slowly added to the mixture. After 15 h at 80° C., the mixture was filtered and the resulting solution was poured into cold water. The methylated compound precipitated and was recovered by filtration and dried under vacuum. The typical yield was 80%.

(152) Etherification was implemented with successively: divanillyl alcohol (DVA; T=CH.sub.2OH) (as obtained in point A1 of Example 1 above), to obtain methylated divanillyl alcohol (mDVA). Said mDVA was characterized by NMR spectroscopy:

(153) ##STR00053##

(154) 1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 6.99 (d, H.sub.1), 6.67 (d, H.sub.5), 5.15 (s, H.sub.10), 4.47 (s, H.sub.9), 3.83 (s, H.sub.7), 3.50 (s, H.sub.8).

(155) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 152.00 (s, C.sub.3), 144.81 (s, C.sub.2), 137.64 (s, C.sub.6), 132.12 (s, C.sub.4), 120.33 (s, C.sub.5), 110.18 (s, C.sub.1), 62.63 (s, C.sub.9), 59.91 (s, C.sub.8), 55.52 (C.sub.7). methyl divanillate (MDEV; T=—COOCH.sub.3) (as obtained in point A4 of Example 4 above), to obtain methylated methyl divanillate (mDVE). This was characterized by spectroscopy:

(156) ##STR00054##

(157) 1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 7.59 (d, H.sub.1), 7.40 (d, H.sub.5), 3.92 (s, H.sub.7), 3.83 (s, H.sub.10), 3.62 (s, H.sub.8).

(158) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 165.67 (s, C.sub.9), 152.27 (s, C.sub.3), 150.36 (s, C.sub.2), 131.28 (s, C.sub.6), 124.70 (s, C.sub.4), 123.96 (s, C.sub.5), 112.76 (s, C.sub.1), 60.29 (s, C.sub.8), 55.92 (s, C.sub.7), 52.18 (C.sub.10).

(159) Said methylated methyl divanillate was then hydrolyzed under the conditions specified below. 10 mmol of methyl divanillate was solubilized in 30 mL of methanol. 3 g of sodium hydroxide (75 mmol) were added to the mixture, which was then stirred and heated at reflux for 4 h. After cooling to room temperature, an aqueous solution of hydrochloric acid (2 M) was added until pH=3 was reached. The resulting precipitate (methylated divanillic acid (mDVAc)) was then filtered and dried at 80° C. in an oven under reduced pressure. Said methylated divanillic acid (mDVAc) was characterized by NMR spectroscopy:

(160) ##STR00055##

(161) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 12.94 (s, H.sub.10), 7.58 (d, H.sub.1), 7.39 (d, H.sub.5), 3.91 (s, H.sub.7), 3.61 (s, H.sub.8).

(162) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 166.83 (s, C.sub.9), 152.20 (s, C.sub.3), 150.07 (s, C.sub.2), 131.34 (s, C.sub.6), 125.91 (s, C.sub.4), 124.13 (s, C.sub.5), 112.93 (s, C.sub.1), 60.28 (s, C.sub.8), 55.87 (s, C.sub.7). dieugenol (DEG; T=—CH.sub.2—CH═CH.sub.2) (as obtained in point A5 of Example 5 above), to obtain methylated dieugenol (mDEG). Said mDEG was characterized by NMR spectroscopy:

(163) ##STR00056##

(164) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 6.85 (d, H.sub.1), 6.54 (d, H.sub.5), 5.96 (m, H.sub.10), 5.07 (m, H.sub.11), 3.81 (s, H.sub.7), 3.48 (s, H.sub.8), 3.34 (d, H.sub.9)

(165) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 152.16 (s, C.sub.2), 144.41 (s, C.sub.3), 137.67 (s, C.sub.10), 134.78 (s, C.sub.6), 132.29 (s, C.sub.4), 122.26 (s, C.sub.5), 115.80 (s, C.sub.11), 112.17 (s, C.sub.1), 59.91 (s, C.sub.7), 55.58 (s, C.sub.9), 39.22 (s, C.sub.7), 35.76 (s, C.sub.7).

(166) Synthesis of Compounds of Formula (I) (Multi-Epoxidized Prepolymers)

(167) Epoxidation was carried out as described above: (with epichlorohydrin) to epoxidize the alcohol functions of mDVA. The diglycidyl ether of methylated divanillyl alcohol (DiGEmDVA) was obtained. Said DiGEmDVA was characterized by NMR spectroscopy:

(168) ##STR00057##

(169) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 7.01 (d, H.sub.1), 6.72 (d, H.sub.5), 4.49 (t, H.sub.9), 3.84 (d, H.sub.7), 3.77 (m, H.sub.10), 3.52 (s, H.sub.8), 3.31 (m, H.sub.10b), 3.15 (m, H.sub.11), 2.73 (t, H.sub.12), 2.55 (m, H.sub.12b).

(170) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 152.20 (s, C.sub.3), 145.48 (s, C.sub.2), 133.25 (s, C.sub.6), 131.98 (s, C.sub.4), 121.66 (s, C.sub.5), 111.35 (s, C.sub.1), 71.90 (s, C.sub.9), 70.71 (s, C.sub.10), 59.90 (s, C.sub.8), 55.61 (s, C.sub.7), 50.27 (s, C.sub.11), 43.41 (s, C.sub.12).

(171) The spectra are shown in FIGS. 11A and 11B respectively. (with epichlorohydrin) to epoxidize the acid functions of mDVAc. The diglycidyl ether of methylated divanillic acid (DiGEmDVAc) was obtained. Said DiGEmDVAc was characterized by NMR spectroscopy:

(172) ##STR00058##

(173) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 7.61 (d, H.sub.1), 7.45 (d, H.sub.5), 4.65 (d, H.sub.10), 4.08 (q, H.sub.10b), 3.93 (s, H.sub.7), 3.64 (m, H.sub.8), 3.34 (m, H.sub.11), 2.82 (m, H.sub.12), 2.72 (m, H.sub.12b).

(174) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 164.92 (s, C.sub.9), 152.34 (s, C.sub.3), 150.55 (s, C.sub.2), 131.28 (s, C.sub.6), 124.41 (s, C.sub.4), 124.04 (s, C.sub.5), 112.92 (s, C.sub.1), 65.58 (s, C.sub.10), 60.34 (s, C.sub.8), 55.97 (s, C.sub.7), 49.01 (s, C.sub.11), 43.90 (s, C.sub.12).

(175) The spectra are shown in FIGS. 12A and 12B respectively. (with the oxidant CPBA) to epoxidize the double bonds of dieugenol. The diglycidyl ether of methylated dieugenol (DiGEmDEG) was obtained. Said DiGEmDEG was characterized by NMR spectroscopy:

(176) ##STR00059##

(177) .sup.1H NMR (400 MHz, DMSO-d6, δ (ppm)): δ 6.95 (d, H.sub.1), 6.66 (d, H.sub.5), 3.83 (s, H.sub.7), 3.51 (s, H.sub.8), 3.12 (m, H.sub.10), 2.74 (m, H.sub.9), 2.57 (m, H.sub.11)

(178) .sup.13C NMR (400 MHz, DMSO-d6, δ (ppm)): δ 152.15 (s, C.sub.2), 144.77 (s, C.sub.3), 132.67 (s, C.sub.6), 132.24 (s, C.sub.4), 122.84 (s, C.sub.5), 112.80 (s, C.sub.1), 59.95 (s, C.sub.8), 55.65 (s, C.sub.7), 52.05 (s, C.sub.10), 46.15 (s, C.sub.11), 37.90 (s, C.sub.9).

(179) The spectra are shown in FIGS. 13A and 13B respectively.

(180) B6. Polyepoxides Obtained from Said Compounds of Formula (I) (Multi-Epoxidized Prepolymers)

(181) For the polymerization of the compounds of the invention obtained in this example, diaminodiphenyl sulfone (DDS), whose chemical formula has been recalled above, was also used as a hardener.

(182) This hardener was used in a stoichiometric ratio: epoxy/amine=2/1. The polyepoxides were not successively prepared and then analyzed by DMA (for determination of its Tg). They were generated, in small amounts (a few mg), during the implementation of differential scanning calorimetry (DSC), for determination of their Tg.

(183) The rate of residual coke, after degradation at 900° C., determined by thermogravimetric analysis (TGA), was determined on the small amount of DiGEmDVac generated during the DSC analysis. The results are shown in Table 5 below.

(184) TABLE-US-00005 TABLE 5 Polyepoxide precursor prepolymers Tg (° C.) Char900 (%) DiGEmDVA 211 47 DiGEmDVAc 175 32 DiGEmDEG 134 nd* *nd = not determined.