SELF-HEALING COMPOSITION

Abstract

The invention relates to a self-healing composition based on at least one elastomer matrix comprising a segment chosen from polysiloxanes, polyesters, polyethers, polycarbonates and polyolefins and a polyurea or polyurethane segment and on at least one polymer material as healing additive, to its process of preparation, to its uses, to an electrical and/or optical cable comprising a layer obtained from said composition, and to a specific healing additive.

Claims

1. A self-healing composition comprising at least one elastomer matrix corresponding to the following formula (I): ##STR00033## in which: m and n are such that the molar mass of the elastomer matrix of formula (I) is between 2 and 200 kg/mol, SM.sub.1 is a segment chosen from polysiloxanes, polyesters, polyethers, polycarbonates and polyolefins, said segment SM.sub.1 being combined with a polyurea or polyurethane segment SD.sub.1, in which: R.sub.1 is a divalent alkylene, arylene or aralkylene group comprising from 3 to 20 carbon atoms, R.sub.2 is a divalent alkylene, arylene or aralkylene group comprising from 1 to 30 carbon atoms, said group optionally comprising one or more heteroatoms chosen from an oxygen atom, a sulfur atom or a halogen atom, X.sub.1 and X.sub.2, which are identical, are oxygen —O— atoms or amine —NH— groups, and n≥0, wherein said self-healing composition additionally comprises a polymer material corresponding to the following formula (II): ##STR00034## in which: 0≤s≤10, R.sub.3 is an at least trivalent alkylene, arylene or aralkylene group comprising from 3 to 30 carbon atoms, said R.sub.3 group optionally comprising one or more heteroatoms chosen from an oxygen atom, a nitrogen atom and one of their mixtures, it being possible for said R.sub.3 group to be substituted by 1, 2 or 3 additional —NH—C(═O)X′.sub.1-E groups, X′.sub.1 is an oxygen —O— atom, an amine —NH— group or an amine —NR.sub.4— group, R.sub.4 being an alkyl group comprising from 1 to 12 carbon atoms, a benzyl group, an allyl group, or an alkylene group such that and the X.sub.3 group as defined below together form a ring, and E corresponds to the following formula (II′): ##STR00035## in which: SM.sub.2 is a segment chosen from polysiloxanes, polyesters, polyethers, polycarbonates and polyolefins, said segment SM.sub.2 being combined with a segment SD.sub.2, in which: R′.sub.1 is a divalent alkylene, arylene or aralkylene group comprising from 3 to 20 carbon atoms, R′.sub.2 is a divalent alkylene, arylene or aralkylene group comprising from 1 to 30 carbon atoms, said group optionally comprising one or more heteroatoms chosen from an oxygen atom, a sulfur atom or a halogen atom, X.sub.1 is as defined above for the formula (I), X′.sub.1 is as defined above for the formula (II), X′.sub.2 is an oxygen —O— atom, an amine —NH— group or an amine —NR.sub.5— group, R.sub.5 being an alkyl group comprising from 1 to 12 carbon atoms, a benzyl group or an allyl group, X.sub.3 is an amine —NH— group or an amine —NR.sub.6— group, R.sub.6 being an alkyl group comprising from 1 to 12 carbon atoms, a benzyl group or an allyl group, X.sub.4 is an oxygen atom or a sulfur atom, p≥0, 0<q≤1, and p, q, r and s are such that the molar mass of the polymer material of formula (II) is between 1 and 200 kg/mol, said elastomer matrix (I) and said polymer material (II) being such that: when X.sub.1 is an amine —NH— group, X′.sub.1 is other than an oxygen —O— atom, X′.sub.2 is other than an oxygen —O— atom when p≠0, and at least one of the following definitions applies: X.sub.4 is a sulfur atom, X′.sub.1 is an amine —NR.sub.4— group, X′.sub.2 is an amine —NR.sub.5— group and p≠0, X.sub.3 is an amine —NR.sub.6— group, when X.sub.1 is an oxygen —O— atom, X′.sub.1 is an oxygen —O— atom, X′.sub.2 is an oxygen —O— atom when p≠0, and at least one of the following definitions applies: X.sub.4 is a sulfur atom, X.sub.3 is an amine —NR.sub.6— group.

2. The self-healing composition comprising at least one elastomer matrix corresponding to the formula (I) as defined in claim 1 and a polymer material corresponding to the following formula (IIa): ##STR00036## Formula (IIa) having: SM.sub.2, said segment SM.sub.2 being combined with a segment SD.sub.2, in which: R′.sub.1, R′.sub.2, X′.sub.1 is an oxygen —O— atom, an amine —NH— group, an amine —NR.sub.4— group, or a mixture of an amine —NH— group and of an amine —NR.sub.4— group, R.sub.4, X′.sub.2 is an oxygen —O— atom, an amine —NH— group, an amine —NR.sub.5— group, or a mixture of an amine —NH— group and of an amine —NR.sub.5— group, R.sub.5, X.sub.3 is an amine —NH— group, an amine —NR.sub.6— group, or a mixture of an amine —NH— group and of an amine —NR.sub.6— group, R.sub.6, X.sub.4 is an oxygen atom or a sulfur atom, p, q=1, and p and r are such that the molar mass of the polymer material of formula (IIa) is between 1 and 200 kg/mol approximately, said elastomer matrix (I) and said polymer material (IIa) being such that: when X.sub.1 is an amine —NH— group, X′.sub.1 is other than an oxygen —O— atom, X′.sub.2 is other than an oxygen —O— atom when p≠0, and at least one of the following definitions applies: X′.sub.1 is a mixture of an amine —NH— group and of an amine —NR.sub.4— group, X′.sub.2 is a mixture of an amine —NH— group and of an amine —NR.sub.5— group, and p≠0, X.sub.3 is a mixture of an amine —NH— group and of an amine —NR.sub.6— group, when X.sub.1 is an oxygen —O— atom, X′.sub.1 is an oxygen —O— atom, X′.sub.2 is an oxygen —O— atom when p≠0, and X.sub.3 is a mixture of an amine —NH— group and of an amine —NR.sub.6— group.

3. The self-healing composition according to claim 1, wherein R.sub.1 and R′.sub.1, which are identical or different, are chosen from the following formulae: ##STR00037## in which the # signs represent the points of attachment of the R.sub.1 radical and of the R′.sub.1 radical to the NH radicals and of the R′.sub.1 radical to the X.sub.3 radicals.

4. The self-healing composition according to claim 1, wherein R.sub.1 and R′.sub.1, which are identical, are chosen from the following formulae: ##STR00038## in which the # signs represent the points of attachment of the R.sub.1 radical and of the R′.sub.1 radical to the NH radicals and of the R′.sub.1 radical to the X.sub.3 radicals.

5. The self-healing composition according to claim 1, wherein: when X′.sub.2 is an amine —NH— and/or —NR.sub.5— group, R′.sub.2 is chosen from an alkylene group comprising from 2 to 12 carbon atoms and the groups having the following formulae: ##STR00039## in which the # signs represent the points of attachment of the R′.sub.2 radical to the X′.sub.2 radicals, when X′.sub.2 is an oxygen —O— atom, R′.sub.2 is chosen from an alkylene group comprising from 2 to 12 carbon atoms and the groups having the following formulae: ##STR00040## in which the # signs represent the points of attachment of the R′.sub.2 radical to the X′.sub.2 radicals.

6. The self-healing composition according to claim 1, wherein the segments SM.sub.1 and SM.sub.2 are polysiloxanes or polyethers.

7. The self-healing composition according to claim 1, wherein X.sub.1 is an amine —NH— group, X′.sub.1 is an amine —NH— or —NR.sub.4— group, X.sub.3 is an amine —NH— or —NR.sub.6— group and X.sub.4 is a sulfur atom.

8. The self-healing composition according to claim 1, wherein X.sub.1 is an amine —NH— group, X′.sub.1 is an amine —NR.sub.4— group, X.sub.3 is an amine —NH— or —NR.sub.6— group and X.sub.4 is an oxygen atom.

9. The self-healing composition according to claim 1, wherein X.sub.1 is an oxygen —O— atom, X′.sub.1 is an oxygen —O— atom, X.sub.3 is an amine —NR.sub.6— group and X.sub.4 is an oxygen atom.

10. The self-healing composition according to claim 1, wherein R.sub.3 is chosen from an alkylene group comprising from 3 to 24 carbon atoms and the groups having the following formulae: ##STR00041## in which the # signs represent the points of attachment of the R.sub.3 radical to the —NH— radicals.

11. The self-healing composition according to claim 1, wherein the ratio: molar mass segment SD.sub.2/(molar mass segment SD.sub.2+molar mass segment SM.sub.2), varies from 0.01 to 0.6.

12. The self-healing composition according to claim 1, wherein: when X.sub.2 is an amine —NH— group, R.sub.2 is chosen from an alkylene group comprising from 2 to 12 carbon atoms and the groups having the following formulae: ##STR00042## in which the # signs represent the points of attachment of the R.sub.2 radical to the X.sub.2 radicals, when X.sub.2 is an oxygen —O— atom, R.sub.2 is chosen from an alkylene group comprising from 2 to 12 carbon atoms and the groups having the following formulae: ##STR00043## in which the # signs represent the points of attachment of the R.sub.2 radical to the X.sub.2 radicals.

13. The self-healing composition according to claim 1, wherein the ratio: molar mass segment SD.sub.1/(molar mass segment SD.sub.1+molar mass segment SM.sub.1) in the elastomer (I), varies from 0.01 to 0.6.

14. The self-healing composition according to claim 1, wherein the composition additionally comprises at least one inorganic filler.

15. The self-healing composition according to claim 1, wherein the polymer material (II) or (IIa) represents from 0.1% to 100% by weight, with respect to the total weight of the elastomer matrix (I).

16. A process for the preparation of a composition as defined in claim 1, wherein said process comprises at least one stage of mixing the elastomer (I) with the polymer material (II) or (IIa), by the solvent route or by the molten route.

17. A healing additive for an elastomer for an elastomer corresponding to the formula (I), wherein said healing additive comprises at least a polymer material corresponding to the formula (II) or (IIa), said formulae (II) and (IIa) as defined in claim 1.

18. An ambient temperature self-healing material, said ambient temperature self-healing material comprises at least said self-healing composition as defined in claim 1.

19. A seal, coating, vibration damping material, and/or an insulating material for an electrical and/or optical cable, comprising: a self-healing composition as defined in claim 1.

20. An electrical and/or optical cable comprising at least one electrical and/or optical conducting element and at least one polymer layer surrounding the electrical and/or optical conducting element, wherein the polymer layer is obtained from a self-healing composition as defined in claim 1.

21. A healing additive, wherein said healing additive is a polymer material corresponding to the formula (II) as defined in claim 1 and in which X′.sub.1 is an amine N-ethyl, N-benzyl or N-allyl group, X.sub.3 is an amine —NH— group, SM.sub.2 is a polydimethylsiloxane segment and X.sub.4 is an oxygen atom.

Description

EXAMPLES

[0213] In the examples, the molar mass of the polymers was measured by the “SEC” (Size Exclusion Chromatography) method.

[0214] Size exclusion chromatography (SEC) measurements were carried out with three PL Gel Mixte C using 5 μm columns (commercial product from Agilent) (7.5×300 mm; having separation limits: 0.2 to 2000 kg.Math.mol.sup.−1) maintained at 40° C., which are coupled to a solvent distribution module and to a Viscotek 3580 differential refractive index (RI) detector of samples. The mobile phase used is composed of THF, at a flow rate of 1 ml.Math.min.sup.−1, and toluene was used as flow rate marker. All the polymers according to the invention were injected (100 μl) at a concentration of 5 mg.Math.ml.sup.−1 after filtration through a 0.45 μm membrane. An OmniSEC data analysis device was used for the acquisition and the analysis of the data. The molar masses (Mn, number-average molar mass, Mw, weight-average molar mass) and the dispersity (=Mw/Mn) were derived from a calibration curve based on the polystyrene (PS) standards from Polymer Standards Service.

[0215] Other techniques than the SEC technique for determining the molar mass of the compositions according to the invention and known to a person skilled in the art of the field of polymers can be envisaged.

Example 1: Preparation of a Self-Healing Composition C1 in Accordance with the Invention

[0216] 1.1 Preparation of a Polymer Material Corresponding to the Formula (II-1)

[0217] A polymer material of following formula (II-1):

##STR00014##

[0218] was prepared in the following way:

[0219] Isophorone diisocyanate (IPDI; 0.78 mmol) was dissolved at ambient temperature under an inert atmosphere (N.sub.2) in 20 ml of anhydrous tetrahydrofuran (THF) in a round-bottomed reaction flask, and then a polydimethylsiloxane substituted in the end positions by N-ethylaminoisobutyl (DMS-A214; 0.78 mmol) was added to the round-bottomed flask, as well as a catalytic amount of triethylamine. The solution was subsequently stirred for 12 days. The completion of the reaction was confirmed by infrared spectroscopy by the disappearance of the absorption peak of the isocyanate. Once the reaction was finished, the solvent was evaporated. The product obtained was then dissolved in 20 ml of dichloromethane and then washed with 3×10 ml of distilled water. The resulting organic phase was dried under vacuum (10.sup.−3 mbar) at 70° C. for 2 days. 1.8 g of product were obtained (87% yield).

[0220] 1.2 Preparation of the Self-Healing Composition C1

[0221] In order to prepare the self-healing composition, an elastomer matrix sold under the reference Geniomer 80 and corresponding to the following formula (I-1):

##STR00015##

[0222] was used.

To do this, 5 g of elastomer matrix of formula (I-1) and 538 mg of polymer material of formula (II-1) as prepared in Example 1.1 above were dissolved in 20 ml and 2 ml of THF respectively. After stirring for one hour, the solution containing the polymer material of formula (II-1) was added to that containing the elastomer matrix of formula (I-1) and then the resulting mixture was left stirring for 3 hours. After complete homogenization, the resulting mixture was transferred into a mould making possible the slow evaporation of the solvent. The mould was left under a ventilated hood for 24 h and then the mixture was dried under vacuum (10.sup.−3 mbar) at 70° C. for 2 days in order to obtain a healing composition C1.

Example 2: Preparation of a Self-Healing Composition C2 in Accordance with the Invention

[0223] 2.1 Preparation of a Polymer Material Corresponding to the Formula (II-2)

[0224] A polymer material of following formula (II-2):

##STR00016##

[0225] was prepared in the following way:

[0226] Toluene 2,4-diisothiocyanate (0.57 mmol) was dissolved at ambient temperature under an inert atmosphere (N.sub.2) in 20 ml of anhydrous THF in a round-bottomed reaction flask. Then, a polydimethylsiloxane substituted in the end positions by 3-aminopropyl (FluidNH40d; 0.60 mmol) was dissolved in 18 ml of anhydrous THF and the resulting solution was added to the round-bottomed flask using a syringe driver (with a flow rate of 1.3 ml/h). The resulting solution was stirred for 17 hours. The completion of the reaction was confirmed by infrared spectroscopy by the disappearance of the absorption peak of the isothiocyanate. Once the reaction was finished, the product obtained was purified by precipitation from methanol (300 ml), followed by filtration and by drying under vacuum (10.sup.−3 mbar) at 70° C. for 2 days. 1.46 g of product were obtained (75% yield).

[0227] 2.2 Preparation of an Elastomer Matrix Corresponding to the Formula (I-2)

[0228] An elastomer matrix of following formula (I-2):

##STR00017##

[0229] was prepared in the following way:

[0230] Toluene 2,4-diisocyanate (11.85 mmol) was dissolved at ambient temperature under an inert atmosphere (N.sub.2) in 200 ml of anhydrous THF in a round-bottomed reaction flask, and then a polydimethylsiloxane substituted in the end positions by 3-aminopropyl (FluidNH40d; 8.98 mmol) was added to the round-bottomed flask. The resulting solution was stirred for 3 hours. An additional amount of substituted polydimethylsiloxane (2.99 mmol) dissolved in 10 ml of anhydrous THF was added using a syringe driver (with a flow rate of 1.4 ml/h). At the end of the addition, the completion of the reaction was confirmed by infrared spectroscopy by the disappearance of the absorption peak of the isocyanate. Once the reaction was finished, the product obtained was purified by precipitation from methanol (1.5 l), followed by filtration and by drying under vacuum (10.sup.−3 mbar) at 70° C. for 2 days. 35.68 g of product were obtained (88% yield).

[0231] 2.3 Preparation of the Self-Healing Composition C2

[0232] 5 g of elastomer matrix of formula (I-2) as prepared in Example 2.2 above and 520 mg of polymer material of formula (II-2) as prepared in Example 2.1 above were dissolved in 20 ml and 2 ml of THF respectively. After stirring for 1 hour, the solution containing the polymer material was added to that containing the elastomer matrix and then the resulting mixture was left stirring for 3 hours. After complete homogenization, the resulting mixture was transferred into a mould making possible the slow evaporation of the solvent. The mould was left under a ventilated hood for 24 h and then the mixture was dried under vacuum (10.sup.−3 mbar) at 70° C. for 2 days in order to obtain a healing composition C2.

Example 3: Preparation of a Self-Healing Composition C3 in Accordance with the Invention

[0233] 3.1 Preparation of a Polymer Material Corresponding to the Formula (II-3)

[0234] A polymer material of following formula (II-3):

##STR00018##

[0235] was prepared in the following way:

[0236] Toluene 2,4-diisocyanate (1 mmol) was dissolved at ambient temperature under an inert atmosphere (N.sub.2) in 20 ml of anhydrous THF in a round-bottomed reaction flask. Then, a polydimethylsiloxane substituted in the end positions by N-ethylaminoisobutyl (DMS-A214; 1.1 mmol) was added to the round-bottomed flask. The resulting solution was stirred for 24 hours. The completion of the reaction was confirmed by infrared spectroscopy by the disappearance of the absorption peak of the isocyanate. Once the reaction was finished, the solvent was evaporated and the product obtained dried under vacuum (10.sup.−3 mbar) at 70° C. for 2 days. 2.6 g of product were obtained (98% yield).

[0237] 3.2 Preparation of an Elastomer Matrix Corresponding to the Formula (I-3)

[0238] An elastomer matrix of following formula (I-3):

##STR00019##

was prepared in the following way:

[0239] Toluene 2,4-diisocyanate (TDI; 7.39 mmol) was dissolved at ambient temperature under an inert atmosphere (N.sub.2) in 200 ml of anhydrous THF in a round-bottomed reaction flask, and then a polydimethylsiloxane substituted in the end positions by 3-aminopropyl (FluidNH40d; 4.49 mmol) was added to the round-bottomed flask. The resulting solution was stirred for 4 hours. 1,3-Diaminopentane sold under the reference Dytek EP diamine (3.1 mmol) dissolved in 20 ml of dimethylformamide (DMF) was added to the round-bottomed flask using a syringe driver (with a flow rate of 1 ml/h). At the end of the addition, the completion of the reaction was confirmed by infrared spectroscopy by the disappearance of the absorption peak of the isocyanate. Once the reaction was finished, the product obtained was purified by precipitation from methanol (1.5 l), followed by filtration and by drying under vacuum (10.sup.−3 mbar) at 70° C. for 2 days. 13.72 g of product were obtained (85% yield).

[0240] 3.3 Preparation of the Self-Healing Composition C3

[0241] 4 g of elastomer matrix of formula (I-3) as prepared in Example 3.2 above and 496 mg of polymer material of formula (II-3) as prepared in Example 3.1 above were dissolved in 40 ml and 2 ml of THF respectively. After stirring for 1 hour, the solution containing the polymer material was added to that containing the elastomer matrix and then the resulting mixture was left stirring for 4 hours. After complete homogenization, the resulting mixture was transferred into a mould making possible the slow evaporation of the solvent. The mould was left under a ventilated hood for 24 h and then the mixture was dried under vacuum (10.sup.−3 mbar) at 70° C. for 2 days in order to obtain a healing composition C3.

Example 4: Physicochemical Characterizations of the Self-Healing Compositions C1, C2 and C3 in Accordance with the Invention

[0242] The Young's modulus (in MPa), the breaking stress (in MPa) and the elongation at break (as %) were determined using a device sold under the trade name Instron 5565 by Instron in the following way: the values of the breaking stress and also of the elongation at break were measured directly during the breaking of the material. As regards the Young's modulus, the value was determined by analysis of the slope of the stress/strain curve, over the first 5% of strain.

[0243] The self-healing nature was demonstrated in the following way: either by visual monitoring of closure of a notch (Example 1) or by recovery of the breaking stress at a given time of a sample prenotched over half of its width (Examples 2 and 3).

[0244] Table 1 illustrated below lists the values of Young's modulus, breaking stress and elongation at break, before notching, of the compositions C1, C2 and C3, and by way of comparison of the elastomer matrices (I-1), (I-2) and (I-3) as prepared in Examples 1 to 3 above, and also the self-healing times (in hours) and self-healing percentages (as %) of the compositions C1, C2 and C3 after notching.

TABLE-US-00001 TABLE 1 self- healing % Young's breaking elongation time of self- modulus stress at break compositions (h) healing (MPa) (MPa) (%) (I-1) 7 0 3.8 2.9 430 C1 7 85 1.9 1.9 470 (I-2) 24 0 1.5 0.73 790 C2 24 17 1.5 0.73 700 (I-3) 24 0 17 3.3 200 C3 24 45 14 1.7 70

[0245] The compositions have a breaking stress which can be lowered with respect to the elastomers of formula (I). However, the recovery of the breaking stress of the compositions is greater than for the elastomers (e.g. from 17% to 85% for the compositions and 0% for the elastomers). The addition of a polymer material of formula (II) thus accelerates the self-repairing kinetics of the composition, while guaranteeing good mechanical properties.

[0246] The appended FIG. 1 shows the self-healing properties of the composition C1 and by way of comparison of the elastomer I-1 when they were subjected to the following protocol: notches were produced with a cutter in layers obtained from the composition C1 (FIG. 1A) and from the elastomer I-1 (FIG. 1B), then the self-repairing was followed visually at ambient temperature as a function of the time. It is observed, after 6 days at ambient temperature, that the notch was strongly resorbed only in the case of the composition C1 (FIG. 1A). The black line represents the original size of the notch (2.5 cm).

Example 5: Preparation of a Self-Healing Composition C4 in Accordance with the Invention

[0247] 5.1 Preparation of a Polymer Material Corresponding to the Formula (II-4)

[0248] A polymer material of following formula (II-4):

##STR00020##

was prepared in the following way:

[0249] A commercial elastomer matrix corresponding to the following formula (I-4):

##STR00021##

(10 g; 20.4 mmol of urethane functional group) was dissolved in 500 ml of anhydrous tetrahydrofuran (THF) in a dry round-bottomed reaction flask at ambient temperature under an inert atmosphere (argon, also subsequently denoted Ar). Sodium hydride (NaH; 1.47 g; 61.25 mmol; 60% in mineral oil) was washed twice with 30 ml of anhydrous tetrahydrofuran (THF), in order to remove the mineral oil, under an inert atmosphere (Ar), in a second dry round-bottomed reaction flask under an inert atmosphere (Ar). 50 ml of tetrahydrofuran (THF) were introduced into this round-bottomed reaction flask. The reaction medium was cooled using a bath of ice-cold water (5° C.) and then stirred under an inert atmosphere. The solution containing the elastomer matrix (I-4) was transferred by hollow needle in 40 minutes into the round-bottomed flask containing sodium hydride in THF. At the end of the addition, the bath of ice-cold water was removed and three vacuum-argon cycles were carried out in the reaction medium. After stirring for 1 hour, iodomethane (CH.sub.3I; 4.11 ml; 66.08 mmol) was added dropwise to the reaction medium. The completion of the reaction was confirmed by proton nuclear magnetic resonance (+I NMR) by the disappearance of the peak of the N—H bonds (8.90-8.95 ppm) and the appearance of the CH.sub.3—N peak (3.17 ppm). After stirring at ambient temperature for 3 h, the reaction was halted by the addition of methanol (MeOH; 1.51 ml; 44 mmol). Once the reaction was finished, the product obtained was purified by precipitation from water (1000 ml), followed by filtration, washing with water and drying under vacuum (10.sup.−3 mbar) at 40° C. for 1 day. 8.9 g of product were obtained (87% yield). The number-average molar mass (Mn) of the polymer (II-4), measured by SEC, is 63 249 g/mol.

[0250] 5.2 Preparation of the Self-Healing Composition C4

[0251] 15.57 g of commercial elastomer matrix of formula (I-4) as defined above and 4.67 g of polymer material of formula (II-4) as prepared in Example 5.1 above were dissolved in 150 ml and 50 ml of THF respectively. After the dissolutions had been completed with stirring, the solution containing the polymer material (II-4) was added to that containing the elastomer matrix (I-4) and then the resulting mixture was left stirring for one hour. After homogenization, the resulting mixture was transferred into several moulds making possible the slow evaporation of the solvent. The moulds were left under a ventilated hood for 24 h and then the films obtained were dried under vacuum (10.sup.−3 mbar) at 40° C. for 1 day in order to obtain a self-healing composition C4.

Example 6: Preparation of a Self-Healing Composition C5 in Accordance with the Invention

[0252] 6.1 Preparation of a polymer material corresponding to the formula (II-5)

[0253] A polymer material of following formula (II-5):

##STR00022##

[0254] was prepared in the following way:

[0255] The elastomer matrix (I-4) as defined above (6.5 g; 13.26 mmol of urethane functional group) was dissolved in 250 ml of anhydrous tetrahydrofuran (THF) in a dry round-bottomed reaction flask at ambient temperature under an inert atmosphere (Ar). Sodium hydride (NaH; 0.987 g; 41.13 mmol; 60% in mineral oil) was washed twice with 20 ml of anhydrous tetrahydrofuran (THF), in order to remove the mineral oil, under an inert atmosphere (Ar), in a second dry round-bottomed reaction flask under an inert atmosphere (Ar). 10 ml of tetrahydrofuran (THF) were introduced into this round-bottomed reaction flask. The reaction medium was cooled using a bath of ice-cold water (5° C.) and then stirred under an inert atmosphere. The solution containing the elastomer matrix (I-4) was transferred by hollow needle in 40 minutes into the round-bottomed flask containing sodium hydride in THF. At the end of the addition, the bath of ice-cold water was removed and three vacuum-argon cycles were carried out in the reaction medium. After stirring for 1 hour, benzyl bromide (BnBr; 4.96 ml; 41.86 mmol) was added dropwise to the reaction medium. The completion of the reaction was confirmed by proton nuclear magnetic resonance (.sup.1H NMR) by the disappearance of the peak of the N—H bonds (8.90-8.95 ppm) and the appearance of the CH.sub.2—N peak (4.72 ppm). After stirring at ambient temperature for 40 h, the reaction was halted by the addition of methanol (MeOH; 1.2 ml; 26.5 mmol). Once the reaction was finished, the reaction medium was introduced into 300 ml of water in order to remove the salts. The mixture of reaction medium and of water is introduced into a separating funnel, into which 400 ml of dichloromethane were introduced in order to extract the organic phase. The latter was dried over MgSO.sub.4 and concentrated. The product obtained was purified by precipitation from pentane (500 ml), followed by filtration and drying under vacuum (10.sup.−3 mbar) at 40° C. for 1 day. 6.50 g of product were obtained (84% yield). The number-average molar mass (Mn) of the polymer (II-5), measured by SEC, is 68 501 g/mol.

[0256] 6.2 Preparation of the Self-Healing Composition C5

[0257] 15.00 g of commercial elastomer matrix of formula (I-4) as defined above and 5.30 g of polymer material of formula (II-5) as prepared in Example 6.1 above were dissolved in 150 ml and 50 ml of THF respectively. After the dissolutions had been completed with stirring, the solution containing the polymer material (II-5) was added to that containing the elastomer matrix (I-4) and then the resulting mixture was left stirring for one hour. After homogenization, the resulting mixture was transferred into several moulds making possible the slow evaporation of the solvent. The moulds were left under a ventilated hood for 24 h and then the films obtained were dried under vacuum (10.sup.−3 mbar) at 40° C. for 1 day in order to obtain a self-healing composition C5.

Example 7: Preparation of a Self-Healing Composition C6 in Accordance with the Invention

[0258] 7.1 Preparation of a Polymer Material Corresponding to the Formula (II-6)

[0259] A polymer material of following formula (II-6):

##STR00023##

[0260] was prepared in the following way:

[0261] A commercial elastomer matrix corresponding to the following formula (I-5):

##STR00024##

[0262] (6.02 g; 12.04 mmol of urethane functional group) was dissolved in 300 ml of anhydrous tetrahydrofuran (THF) in a dry round-bottomed reaction flask at ambient temperature under an inert atmosphere (Ar). Sodium hydride (NaH; 0.8771 g; 36.55 mmol; 60% in mineral oil) was washed twice with 20 ml of anhydrous tetrahydrofuran (THF), in order to remove the mineral oil, under an inert atmosphere (Ar), in a second dry round-bottomed reaction flask under an inert atmosphere (Ar). 10 ml of tetrahydrofuran (THF) were introduced into this round-bottomed reaction flask. The reaction medium was cooled using a bath of ice-cold water (5° C.) and then stirred under an inert atmosphere. The solution containing the elastomer matrix (I-5) was transferred by hollow needle in 40 minutes into the round-bottomed flask containing sodium hydride in THF. At the end of the addition, the bath of ice-cold water was removed and three vacuum-argon cycles were carried out in the reaction medium. After stirring for 1 hour, iodomethane (CH.sub.3I; 2.61 ml; 41.85 mmol) was added dropwise to the reaction medium. The completion of the reaction was confirmed by proton nuclear magnetic resonance (.sup.1H NMR) by the disappearance of the peak of the N—H bonds (8.96-9.01 ppm) and the appearance of the CH.sub.3—N peak (3.17 ppm). After stirring at ambient temperature for 17 h, the reaction was halted by the addition of methanol (MeOH; 1.28 ml; 29.24 mmol). Once the reaction was finished, the tetrahydrofuran was evaporated. The product obtained was washed with a dichloromethane/water mixture. The organic phase was extracted with 120 ml of dichloromethane and washed three times with 120 ml of water. It was dried over MgSO.sub.4, filtered and dried. The product drying under vacuum (10.sup.−3 mbar) at 40° C. for 1 day. 5 g of product were obtained (87% yield). The number-average molar mass (Mn) of the polymer (II-6), measured by SEC, is 42 095 g/mol.

[0263] 7.2 Preparation of the Self-Healing Composition C6

[0264] 15.56 g of commercial elastomer matrix of formula (I-4) as defined above and 4.80 g of polymer material of formula (II-6) as prepared in Example 7.1 above were dissolved in 150 ml and 50 ml of THF respectively. After the dissolutions had been completed with stirring, the solution containing the polymer material (II-6) was added to that containing the elastomer matrix (I-4) and then the resulting mixture was left stirring for one hour. After homogenization, the resulting mixture was transferred into several moulds making possible the slow evaporation of the solvent. The moulds were left under a ventilated hood for 24 h and then the films obtained were dried under vacuum (10.sup.−3 mbar) at 40° C. for 1 day in order to obtain a self-healing composition C6.

Example 8: Preparation of a Self-Healing Composition C7 in Accordance with the Invention

[0265] 8.1 Preparation of a Polymer Material Corresponding to the Formula (II-7)

[0266] A polymer material of following formula (II-7):

##STR00025##

was prepared in the following way:

[0267] The elastomer matrix (I-5) as defined above (6.72 g; 13.44 mmol of urethane functional group) was dissolved in 250 ml of anhydrous tetrahydrofuran (THF) in a dry round-bottomed reaction flask at ambient temperature under an inert atmosphere (Ar). Sodium hydride (NaH; 0.9845 g; 41.02 mmol; 60% in mineral oil) was washed twice with 20 ml of anhydrous tetrahydrofuran (THF), in order to remove the mineral oil, under an inert atmosphere (Ar), in a second dry round-bottomed reaction flask under an inert atmosphere (Ar). 10 ml of tetrahydrofuran (THF) were introduced into this round-bottomed reaction flask. The reaction medium was cooled using a bath of ice-cold water (5° C.) and then stirred under an inert atmosphere. The solution containing the elastomer matrix (I-5) was transferred by hollow needle in 40 minutes into the round-bottomed flask containing sodium hydride in THF. At the end of the addition, the bath of ice-cold water was removed and three vacuum-argon cycles were carried out in the reaction medium. After stirring for 1 hour, benzyl bromide (BnBr; 4.96 ml; 41.02 mmol) was added dropwise to the reaction medium. The completion of the reaction was confirmed by proton nuclear magnetic resonance (.sup.1H NMR) by the disappearance of the peak of the N—H bonds (8.96-9.01 ppm) and the appearance of the CH.sub.2—N peak (4.72 ppm). After stirring at ambient temperature for 42 h, the reaction was halted by the addition of methanol (MeOH; 1.18 ml; 26.95 mmol). Once the reaction was finished, the reaction medium was introduced into 300 ml of water in order to remove the salts. The mixture of reaction medium and of water is introduced into a separating funnel, into which 450 ml of dichloromethane were introduced in order to extract the organic phase. The latter was dried over MgSO.sub.4 and concentrated. The product obtained was purified by precipitation from pentane (450 ml), followed by filtration and drying under vacuum (10.sup.−3 mbar) at 40° C. for 1 day. 5.52 g of product were obtained (70% yield). The number-average molar mass (Mn) of the polymer (II-7), measured by SEC, is 41 966 g/mol.

[0268] 8.2 Preparation of the Self-Healing Composition C7

[0269] 14.79 g of commercial elastomer matrix of formula (I-4) as defined above and 5.11 g of polymer material of formula (II-7) as prepared in Example 8.1 above were dissolved in 150 ml and 50 ml of THF respectively. After the dissolutions had been completed with stirring, the solution containing the polymer material (II-7) was added to that containing the elastomer matrix (I-4) and then the resulting mixture was left stirring for one hour. After homogenization, the resulting mixture was transferred into several moulds making possible the slow evaporation of the solvent. The moulds were left under a ventilated hood for 24 h and then the films obtained were dried under vacuum (10.sup.−3 mbar) at 40° C. for 1 day in order to obtain a self-healing composition C7.

Example 9: Physicochemical Characterizations of the Self-Healing Compositions C4, C5, C6 and C7 in Accordance with the Invention

[0270] The Young's modulus (in MPa), the breaking stress (in MPa) and the elongation at break (as %) were determined by tensile tests carried out at a rate of displacement of 30 mm/min on test specimens with a geometry of 5 A dumbbell type (ISO 527) obtained by an injection moulding process, using a device sold under the trade name Instron 5565 by Instron. The values of the breaking stress and also of the elongation at break were measured directly during the breaking of the material. As regards the Young's modulus, the value was determined by analysis of the slope of the stress/strain curve, between 1% and 1.5% of strain.

[0271] The self-healing nature was demonstrated in the following way: [0272] either by visual monitoring of closure of a notch, [0273] or by recovery of the breaking stress at a given time of a sample of 5 A standardized dumbbell test specimen type, cut in the middle of the working zone and then the two halves of which are directly (t<20 sec) brought back into contact manually for 2 minutes.

[0274] Table 2 illustrated below lists the values of Young's modulus, breaking stress and elongation at break, before cutting and after cutting, of the compositions C4, C5, C6 and C7, and by way of comparison of the elastomer matrices (I-4) and (I-5). Furthermore, the self-healing time (in hours) and the self-healing percentage (as %) are mentioned for each composition.

TABLE-US-00002 TABLE 2 self- healing % Young's breaking elongation time of self- modulus stress at break compositions (h) healing (MPa) (MPa) (%) (I-4) 168 0 5.8 19 1013 (I-5) 168 0 4.3 11.2 502 C4 24 12 4.3 8 435 C5 24 11 2.3 9.6 1071 C6 24 22 1.6 5.8 660 C7 24 13 1.6 5.8 1495

Example 10: Preparation of a Self-Healing Composition C8 Comprising a Polymer Material of Formula (III)

[0275] 10.1 Preparation of a Polymer Material Corresponding to the Formula (IIa-8)

[0276] A polymer material of following formula (IIa-8):

##STR00026##

[0277] The elastomer matrix (I-4) as defined above (6.12 g; 12.48 mmol of urethane functional group) was dissolved in 250 ml of anhydrous tetrahydrofuran (THF) in a dry round-bottomed reaction flask at ambient temperature under an inert atmosphere (Ar). Sodium hydride (NaH; 0.6023 g; 25.10 mmol; 60% in mineral oil) was washed twice with 20 ml of anhydrous tetrahydrofuran (THF), in order to remove the mineral oil, under an inert atmosphere (Ar), in a second dry round-bottomed reaction flask under an inert atmosphere (Ar). 10 ml of tetrahydrofuran (THF) were introduced into this round-bottomed reaction flask. The reaction medium was cooled using a bath of ice-cold water (5° C.) and then stirred under an inert atmosphere. The solution containing the elastomer matrix (I-4) was transferred by hollow needle in 40 minutes into the round-bottomed flask containing sodium hydride in THF. At the end of the addition, the bath of ice-cold water was removed and three vacuum-argon cycles were carried out in the reaction medium. After stirring for 1 hour, iodomethane (CH.sub.3I; 0.51 ml; 8.24 mmol) was added dropwise to the reaction medium. The completion of the reaction was confirmed by proton nuclear magnetic resonance (.sup.1H NMR) by the decrease in the peak of the N—H bonds (8.90-8.95 ppm) and the appearance of the CH.sub.3—N peak (3.17 ppm). After stirring at ambient temperature for 44 h, the reaction was halted by the addition of methanol (MeOH; 1.15 ml; 26.27 mmol). Once the reaction was finished, the product obtained was purified by precipitation from water (1000 ml), followed by filtration, washing with water and drying under vacuum (10.sup.−3 mbar) at 40° C. for 1 day. 6.19 g of product were obtained (98% yield).

[0278] The polymer (IIa-8) thus obtained statistically comprises a content of R═H at a level of 41% and of CH.sub.3 at 59%.

[0279] 10.2 Preparation of the Self-Healing Composition C8

[0280] 11.49 g of commercial elastomer matrix of formula (I-4) and 4.67 g of polymer material of formula (IIa-8) as prepared in Example 10.1 above were dissolved in 150 ml and 50 ml of THF respectively. After the dissolutions had been completed with stirring, the solution containing the polymer material (IIa-8) was added to that containing the elastomer matrix (I-4) and then the resulting mixture was left stirring for one hour. After homogenization, the resulting mixture was transferred into several moulds making possible the slow evaporation of the solvent. The moulds were left under a ventilated hood for 24 h and then the films obtained were dried under vacuum (10.sup.−3 mbar) at 40° C. for 1 day in order to obtain a self-healing composition C8.

Other Examples of Self-Healing Compositions

[0281] In addition to the preceding examples of compositions in accordance with the invention, other compositions have shown their self-healing properties on using similar proportions of compounds of formula (I) and (II) as described in the preceding examples. [0282] Composition C9 comprising a compound of following formula (I):

##STR00027##

[0283] and a compound of following formula (II):

##STR00028## [0284] Composition C10 comprising a compound of following formula (I):

##STR00029##

[0285] and a compound of following formula (IIa):

##STR00030## [0286] Composition C11 comprising a compound of following formula (I):

##STR00031##

[0287] and a compound of following formula (II):

##STR00032##

[0288] The appended FIG. 2 shows one of the self-healing compositions as defined above, which heals spectacularly after 24 hours, without external stimuli (temperature, pressure, and the like).