DOUBLE DYNAMIC POLYMERS

Abstract

Polymers include a monomer with a polyurethane, a supramolecular moiety, an elastomer moiety and a functional group that includes a —C═N— link. The polymers can be prepared and incorporated into a composition. The polymers can be double dynamic polymers, which present adhesive and self-healing properties. The polymers can also be recyclable.

Claims

1. A polymer comprising a monomer comprising a polyurethane, a supramolecular moiety, an elastomer moiety and a functional group comprising a —C═N— link.

2. The polymer according to claim 1, wherein said monomer comprises the following structure (I): ##STR00034## wherein: n is the number of monomers in the polymer, E is a chemical structure comprising a supramolecular moiety forming a supramolecular structure with a supramolecular moiety of another polymer structure (I), A is a chemical comprising or consisting of an elastomer moiety, and G, D and Q are independently at each occurrence a chemical group of atoms.

3. The polymer according to claim 2, wherein E is selected from the group consisting of ##STR00035## wherein R3 is selected from the group consisting of: H; a saturated or unsaturated and linear or branched C1-C20, hydrocarbon chain which is optionally substituted and optionally interrupted by one or more heteroatoms selected from the group consisting of nitrogen, oxygen, silicon and phosphorus; or a phenyl, optionally substituted.

4. The polymer according to claim 2, wherein D, G and Q are at each occurrence independently selected from the group consisting of: ##STR00036## wherein the alkyl group and/or the phenyl ring are optionally substituted, wherein n is the number of CH2 group.

5. The polymer according to claim 2, wherein D and/or Q is a phenyl, an alkylphenyl a phenylalkyl, an alkylphenylalkyl, a cycloalkyl, said phenyl, alkylphenyl, phenylalkyl, alkylphenylalkyl or cycloalkyl being optionally substituted.

6. The polymer according to claim 2, wherein said functional group comprising a —C═N— link is selected from the group consisting of imine, oxime, hydrazine and acylhydrazone functional groups.

7. The polymer according to claim 2, wherein said elastomer moiety comprises or consists of a polyisoprene, a cis-1,4-polyisoprene, a trans-1,4-polyisoprene a polybutadiene, a chloroprene rubber, a polychloroprene, a neoprene, a baypren, copolymer of isobutylene and isoprene, an halogenated butyl rubbers, a chloro butyl rubber, a bromo butyl rubber, a copolymer of styrene and butadiene, a copolymer of butadiene and acrylonitrile, an hydrogenated nitrile rubbers, a poly(propylene glycol), a poly(dimethylsiloxane), a polyethylene oxide (PEO), a polypropylene oxide (PPO), a poly(tetrahydrofuran) (PTHF), and mixture or copolymer thereof.

8. The polymer according to claim 2, wherein said elastomer has the following structure: ##STR00037##

9. The polymer according to claim 2, wherein said polymer has the following structure: ##STR00038## wherein A, E and n are defined according to claim 2, and p is at each occurrence the same or a different index.

10. The polymer of claim 2, wherein p a number from 4 to 12.

11. The polymer according to claim 1, wherein said polymer is double-dynamic polyurethane elastomer by presenting adhesive properties and self-healing properties.

12. A monomer comprising the following structure: ##STR00039## wherein: B denotes an associative group represented by one of the structures: ##STR00040## in which Z represents an oxygen or sulfur atom; D is a chemical group of atoms; and E is a chemical structure comprising a supramolecular moiety capable of forming a supramolecular structure with a supramolecular moiety of another monomer.

13. The monomer according to claim 12, wherein said monomer presents the following structure: ##STR00041##

14. A process for preparing a polymer comprising a monomer comprising a polyurethane, a supramolecular moiety, an elastomer moiety and a functional group comprising a —C═N— link, said polymer being prepared by reacting a monomer comprising a supramolecular moiety, said monomer being as defined according to claim 12, with a reactive molecule comprising at least two urethane functions and an elastomer moiety, said reactive molecule comprising reactive groups reacting with said monomer to form an imine function, thereby forming said polymer.

15. The process according to claim 14, wherein said reactive molecule presents the following structure: ##STR00042## wherein p is at each occurrence the same or a different index. wherein n represents the number of monomer in the elastomer moiety.

16. A composition comprising at least one polymer is as defined according to claim 1.

17. The polymer according to claim 1 wherein said polymer is a double dynamic polymer, presenting adhesive properties and self-healing properties.

18. The polymer according to claim 1 wherein said polymer is recyclable by pH variation.

19. The monomer of claim 13, wherein said monomer has the following structure: ##STR00043## wherein R3 is selected from the group consisting of: H, an alkyl and a phenyl, optionally substituted.

20. The monomer of claim 19, wherein R3 is: ##STR00044## wherein R4 at each occurrence is independently at each occurrence H or a saturated or unsaturated and linear or branched C1-C20 hydrocarbon chain which is optionally substituted by one or more ═O, —OH or —NH2 groups and optionally interrupted by one or more heteroatoms selected from the group consisting of nitrogen, oxygen, silicon and phosphorus.

21. The polymer according to claim 3, wherein R3 is: ##STR00045## wherein R4 at each occurrence is independently selected from the group consisting of a saturated or unsaturated and linear and branched C1-C20 hydrocarbon chain which is optionally substituted and optionally interrupted by one or more heteroatoms selected from the group consisting of nitrogen or oxygen, silicon and phosphorus; ##STR00046## wherein R2 is selected from the group consisting of: ##STR00047## X1 and X1′ denote independently an oxygen or a nitrogen atom; X denotes a nitrogen atom, or a CR3 group where R3 is selected from the group consisting of hydrogen atom and a linear or branched C1-C20 hydrocarbon chain which is optionally substituted and optionally interrupted by one or more heteroatoms selected from the group consisting of nitrogen or oxygen, silicon and phosphorus; R2 represents a saturated or unsaturated and linear or branched C1-C20 hydrocarbon chain which is optionally substituted and optionally interrupted by one or more heteroatoms selected from the group consisting of nitrogen, oxygen, silicon and phosphorus; R1 and R1′, which are identical or different, represent, independently of one another, a single bond or a saturated or unsaturated and linear or branched C1-C20, hydrocarbon chain which is optionally substituted and optionally interrupted by one or more heteroatoms selected from the group consisting of nitrogen, oxygen, silicon and phosphorus; B denotes an associative group represented by one of the structures: ##STR00048## in which Z represents an oxygen or sulfur atom.

Description

[0143] In the figures:

[0144] FIG. 1: a) Storage modulus vs temperature, obtained by dynamic mechanical analysis, of each thermoplastic material at a frequency of 1 Hz for a temperature range between −70° C. and 150° C.; b) Tan(δ) vs temperature, obtained by DMTA, of each thermoplastic material at a frequency of 1 Hz for a temperature range between −70° C. and 150° C.

[0145] FIG. 2: a) Storage modulus vs temperature, obtained by dynamic mechanical analysis, of each thermoset material at a frequency of 1 Hz for a temperature range between −70° C. and 150° C.; b) Tan(δ) vs temperature, obtained by DMTA, of each thermoset material at a frequency of 1 Hz for a temperature range between −70° C. and 150° C.

EXAMPLES

List of Abbreviations

[0146]

TABLE-US-00001 TABLE 1 Abbreviations DMF Dimethylformamide HFP Hexafluoropropene HDI Hexamethylene diisocyanate HMDI Hydrogenated MDI HRMS High Resolution Mass Spectrometry IMI imine IPDI Isophorone diisocyanate MDI Methylene diphenyl diisocyanate PBD poly (butadiene)diol PPG poly(propyleneglycol) PU-IMI-PBD polyurethane-imine-poly (butadiene)diol PU-PBD polyurethane-poly (butadiene)diol PU-Upy-IMI-PBD polyurethane-Ureidopyrimidone-imine-poly (butadiene)diol PU-Upy-PBD polyurethane-Ureidopyrimidone-poly (butadiene)diol TDI Toluene diisocyanate UPY Ureidopyrimidone

Example 1—Synthesis of Polymers According to the Invention Synthesis of Dialdehyde Precursor

Synthesis of 2-(2-(3-(6-isocyanatohexyl)ureido)-6-methyl-4-oxo-1,4-dihydro pyrimidin-5-yl)ethyl (6-isocyanatohexyl)carbamate (A)

[0147] ##STR00024##

[0148] 2-amino-5-(2-hydroxyethyl)-6-methylpyrimidin-4(1H)-one (2.25 g, 13.3 mmol) was added to a 2-neck round bottomed flask, which was then purged of air with three vacuum/argon cycles and filled with DMF (10 mL). To this stirred suspension, cold hexamethylene diisocyanate (HDI) (20 mL, 124.9 mmol) and pyridine (2 mL) was added; the resulting white suspension was then heated overnight at 90° C. Complete dissolution of the white precipitate was observed after 2 hours at heat and the clear colourless solution turned clear yellow overnight. The solution was then added drop wise to cold diethyl ether (300 mL) producing an off-white precipitate and a clear yellow liquid, which was decanted. The solid was then washed again and decanted from cold diethyl ether (2×300 mL) before being isolated by filtration, washed with diethyl ether (2×100 mL) and dried to leave compound A as an off-white powder (4.5 g, 67%).

[0149] .sup.1H NMR (CDCl.sub.3, 400 MHz, 25° C.) δ=12.95 (s, 1H), 11.92 (s, 1H), 10.17 (s, 1H), 4.70 (s, 1H), 4.19 (t, J=6.2 Hz, 2H), 3.32 (t, J=7.2 Hz, 4H), 3.29 (t, J=6.8 Hz, 2H), 3.18-3.13 (m, 2H), 2.77 (t, J=6.6 Hz, 2H), 2.27 (s, 3H), 1.70-1.30 (m, 16H).

[0150] .sup.13C NMR (CDCl.sub.3, 100 MHz, 25° C.): 6=172.2, 156.7, 156.5, 153.5, 144.9, 113.8, 62.9, 43.0, 42.9, 40.9, 39.8, 31.14, 31.09, 29.9, 29.1, 26.2, 26.1, 26.0, 25.6, 17.2.

Synthesis of 2-(2-(3-(6-(((4-formylphenoxy)carbonyl)amino)hexyl)ureido)-6-methyl-4-oxo-1,4-dihydropyrimidin-5-yI)ethyl (4-formylphenyl) hexane-1,6-diyldicarbamate

[0151] ##STR00025##

[0152] Compound A (1.44 g, 2.8 mmol) and 4-hydroxybenzaldehyde (1.71 g, 14 mmol) were added to a 2-necked round-bottomed flask, and purged of air by three vacuum/argon cycles. Distilled chloroform (15 mL) was added via an addition funnel and dibutyltin dilaurate (2 drops) added by syringe, via the septum, and the resulting solution stirred with heating (60° C.) overnight. The turbid orange suspension was observed to fully dissolve after 2 hours. The solution was then added drop wise to stirred diethyl ether (100 mL), the solid was then washed with ethanol (2×100 mL) and diethyl ether (2×100 mL), before drying to yield compound B as a white powder. (1.82 g, 87%).

[0153] .sup.1H NMR (DMSO d.sub.6, 400 MHz, 25° C.) δ=11.53 (bs, 1H), 9.97 (s, 2H), 9.51 (bs, 1H), 7.93 (d, J=8.2 Hz, 4H), 7.33 (d, J=8.2 Hz, 4H), 7.04 (t, J=5.9 Hz, 1H), 3.96 (t, J=6.6 Hz, 2H), 3.17-3.12 (m, 2H), 3.11-3.05 (m, 4H), 2.98-2.93 (m, 2H), 2.61 (bt, J=6.5 Hz, 2H), 2.16 (s, 3H), 1.50-1.20 (m, 16H).

[0154] .sup.13C NMR (DMSO d.sub.6, 100 MHz, 25° C.): 6=191.9, 156.1, 155.9, 153.4, 132.9, 130.9, 122.2, 115.8, 29.3, 29.3, 29.2, 29.1, 29.0, 29.0, 25.9, 25.9, 25.8.

[0155] Amine-Modification of Polybutadiene

[0156] Identical experimental procedures were used to produce amine-functionalized polybutadienes from both Polyvest® and Krasol® commercial materials. An example of the procedure, using Polyvest® is given below.

##STR00026##

[0157] In a 2-neck round bottomed flask (with an addition funnel containing distilled chloroform and a septum attached), polybutadiene Polyvest® (3.97 g, 0.79 mmol) was added and dried under vacuum for 1 hour. The flask was then filled with argon and the polymer dissolved in chloroform (20 mL). In a separate 2-neck round bottomed flask (with a burette of distilled chloroform and a septum attached), carbonyl diimidazole (CDI) (1.29 g, 8.0 mmol) was added and purged of air with three vacuum/air cycles before being dissolved in chloroform (10 mL). The solution of polybutadiene was added drop wise to the solution of CDI and the resulting colourless solution allowed to stir overnight at room temperature. The solvent was then evaporated in vacuo and cyclohexane (30 mL) was added leading to the formation of a white suspension. The suspension was then filtered, washed with cyclohexane (3×30 mL) and the solution evaporated in vacuo. The resulting viscous liquid polymer was then reacted, without further purification, with 1,6-diaminohexane:

[0158] In a 2-neck round bottomed flask (with an addition funnel of distilled chloroform and a septum attached) the polymer from the previous step was purged of air by three vacuum/argon cycles. Chloroform (30 mL) was then added and the solution stirred to homogeneity before addition to of 1,6-diaminohexane (1.2 g, 10 mmol) in a chloroform solution (50 mL). The resulting solution was then stirred overnight at room temperature. The solution was then precipitated in methanol (500 mL) and the solid residue was dried in vacuo to yield amine-modified polybutadiene as a pale green viscous liquid polymer (3.5 g, 85%).

[0159] Polyvest®-Based Materials

[0160] .sup.1H NMR (CDCl.sub.3, 400 MHz, 25° C.): δ=5.64-5.51 (br), 5.47-5.29 (br), 5.02-4.89 (br), 4.71-4.56 (br), 3.21-3.09 (br), 2.69 (t, J=7.0 Hz), 2.11-1.98 (br), 1.52-1.22 (br).

[0161] Krasol®-Based Materials

[0162] .sup.1H NMR (CDCl.sub.3, 400 MHz, 25° C.): δ=5.57-5.30 (br), 5.01-4.87 (br), 4.66-4.57 (br), 3.20-3.10 (br), 2.69 (t, J=7.0 Hz), 2.20-1.84 (br), 1.50-1.12 (br).

[0163] Synthesis of Thermoplastics

[0164] In a three-necked round bottom flask, amine-modified Krasol®-based polybutadiene (2 g, 0.4 mmol) was added and purged of air by three vacuum/argon cycles, before addition of chloroform (5 mL). In a separate flask, dialdehyde-functionalised ureidopyrimidinone (B) (600 mg, 0.8 mmol) was dissolved in chloroform (5 mL) and added via syringe to the stirred polybutadiene solution.

[0165] The resulting solution was then pipetted into a Teflon® mould and allowed to evaporate in a saturated atmosphere of chloroform, before post-curing at 50° C. under vacuum for 5 hours.

[0166] Synthesis of Thermosets

[0167] In a three-necked round bottom flask, amine-modified Polyvest®-based polybutadiene (2 g, 0.4 mmol) was added and purged of air by three vacuum/argon cycles, before addition of chloroform (5 mL). In a separate flask, dialdehyde-functionalised ureidopyrimidinone (B) (600 mg, 0.8 mmol) was dissolved in chloroform (5 mL) and added via syringe to the stirred polybutadiene solution.

[0168] The resulting solution was then pipetted into a Teflon® mould and allowed to evaporate in a saturated atmosphere of chloroform, before post-curing at 50° C. under vacuum for 5 hours.

Example 2—Mechanical Properties of Polymers According to the Invention Mechanical Properties of Thermoplastics

[0169] Analysis of the behaviour of the materials when stretched at very low strains was conducted using Dynamic Mechanical (Thermal) Analysis (DMTA); the materials were cut to roughly the following dimensions: 40 mm×10 mm×1 mm. For each of the DMTA analyses, a sinusoidal force with strains starting at 0.6%, and a peak and trough at 0.8% and 0.4% respectively, was used. The behaviour of the material was followed by observing the change in storage and loss moduli, as well as tangent delta, for a temperature range from −75° C. to 150° C. and using a frequency range between 0.1 Hz and 15 Hz (FIGS. 1a and b). The mechanical response of the double dynamic thermoplastic was compared to three different control materials: PBD TP CTL0 (amine-modified Krasol® condensed with hexamethylene diisocyanate), PBD TP CTL1 UPy (amine-modified Krasol® condensed with compound A), PBD TP CTL1 Imi (amine-modified Krasol® condensed with bis(4-formylphenyl) hexane-1,6-diyldicarbamate).

[0170] The limit to which the materials could be stretched until their failure, was then analyzed by elongation until break studies. All materials were tested at room temperature with a strain rate of 0.4% s.sup.−1 (Table 2).

TABLE-US-00002 TABLE 2 Average physical parameters of the materials tested by elongation until break, over 6 experiments. PBD TP PBD TP PBD TP Double Thermoplastics CTL0 CTL1 UPy CTL1 Imi Dynamic TP Young's Modulus 1.65 (±0.12) 2.4 (±0.22) 2.1 (±0.17) 3.7 (±0.31) (MPa) Tensile Strength 0.45 (±0.15) 0.8 (±0.29) 0.72 (±0.09) 2 (±0.16) (MPa) Strain at Rupture 0.9 (±0.08) 0.71 (±0.17) 1.2 (±0.10) 1.44 (±0.20) (mm/mm)

[0171] Mechanical Properties of Thermosets

[0172] Analysis of the behavior of the materials when stretched at very low strains was conducted using Dynamic Mechanical (Thermal) Analysis (DMTA); the materials were cut to roughly the following dimensions: 40 mm×10 mm×1 mm. For each of the DMTA analyses, a sinusoidal force with strains starting at 0.6%, and a peak and trough at 0.8% and 0.4% respectively, was used. The behaviour of the material was followed by observing the change in storage and loss moduli, as well as tangent delta, for a temperature range from −75° C. to 150° C. and using a frequency range between 0.1 Hz and 15 Hz (FIGS. 2a and b). The mechanical response of the double dynamic thermoset was compared to three different control materials: PBD CTL0 (amine-modified Polyvest® condensed with hexamethylene diisocyanate), PBD CTL1 UPy (amine-modified Polyvest® condensed with compound A), PBD CTL1 Imi (amine-modified Polyvest® condensed with bis(4-formylphenyl) hexane-1,6-diyldicarbamate).

[0173] The limit to which the materials could be stretched until their failure, was then analyzed by elongation until break studies. All materials were tested at room temperature with a strain rate of 0.4% s.sup.−1 (Table 3).

TABLE-US-00003 TABLE 3 Average physical parameters of the materials tested by elongation until break, over 6 experiments. PBD PBD PDB Double Thermosets CTL0 CTL1 UPy CTL2 Imi Dynamic Young's Modulus (MPa) 2.69 (±0.34)  4.90 (±1.35)  2.7 (±0.25) 14.46 (±3.32) Tensile Strength (MPa) 0.94 (±0.24) >3.10 (±0.86) 2.3 (±0.6) >4.70 (±1.66) Strain at Rupture 0.57 (±0.20) >2.25 (±0.53) 0.6 (±0.3) >1.12 (±0.58) (mm/mm)

Example 3—Self-Healing Properties of Polymers According to the Invention

[0174] Self-Healing Properties of Thermoplastics and Thermosets

[0175] Two different types of cut, namely half-width and half-thickness (half-half) and half-width and full-thickness (half-full) were studied on either thermoplastics or thermosets materials. Cut samples were healed by heating during ˜30 minutes in an iron-like fashion at 50-70° C. (for thermoplastics) and at 110-120° C. (for thermosets). The samples have shown the recovery of mechanical properties close to quantitative after 5 cycles of iron-like procedure.

[0176] Self-healing abilities of different materials have been characterized by inventors below and above viscous flow transition point under mechanical load. All polyurethane samples revealed a self-healing ability at a temperature higher than the viscous flow temperature. Thermoplastics (TPs) show higher self-healing ability regardless of the chemical structure of studied elastomer. Obviously, inter-chains covalent cross-links limited diffusion rates for thermosets (TSs). Both, imine-containing elastomers PU-IMI-PBDs and PU-UPy-IMI-PBD could be properly healed at T>T.sub.v (up to 85-100%) depending on the material. However, it takes at least 180 min to reach healing equilibrium for PU-IMI-PBDs. The inventors did not observe any stress reparation at temperatures below T.sub.v for PU-IMI-PBDs. In contrast, double dynamic PU-UPy-IMI-PBD elastomers revealed outstanding self-healing properties at T>T.sub.v in terms of healing rate and quality. PU-UPy-IMI-PBD TP could repair half of pristine stress at break during 8 min (t.sub.1/2) at 60° C. and could be fully healed after 20 min which is crucially more rapid that any imine-based self-healing elastic materials on inventors' best knowledge. PU-UPy-IMI-PBD TS appeared to be rapidly healable at 100° C. (about 10 minutes for t.sub.112 and 30 minutes for a full stress reparation).

[0177] To explain these self-healing behaviors, and especially drastic increase of self-healing rate, the inventors studied tensile stress relaxation at constant strain knowing already the timescales of healing. As it was explained on the theoretical works of Wool and co-authors (R. P. Wool, K. M. O'Connor, A theory crack healing in polymers. Journal of Applied Physics. 52, 5953-5963 (1981)), self-healing process includes the following steps: surface rearrangements, surface approach, wetting, diffusion, and randomization. For the present invention, where healing was performed under constant mechanical load and the splitting of cut surfaces, only the last three stages should be taken into account. These stages are directly related to the macroscopic mechanical relaxation processes. Temperature dependent stress relaxation tests at constant strain were performed in order to study relations between relaxation process and self-healing of dynamic PUs.

[0178] Generalized Maxwell phenomenological model was applied as one well known for the explanation of stress relaxation behavior of PUs. Stress relaxation spectra of PU-UPy-PBDs include one broad relaxation peak at 30-300 s. depending on temperature. The position of the peak maximum corresponds to characteristic relaxation time of the most prevalent Maxwell elements in the network, and intensity is directly proportional to the quantity of these elements. Plotting logarithm of relaxation time at maximum intensity versus reciprocal temperature gives Arrhenius-like linear dependence. It has been found, that apparent activation energies of this relaxation process is relatively low (10-13 kJ×mol.sup.−1 depend on nonreversible covalent bonds) and cannot be explained by urethane-urethane or UPy-UPy total dissociation which is known to have significantly higher activation energies. Thus, self-healing of PU-UPy-PBDs observed at T<T.sub.v could be governed by motions of hard block H-bonded segments. PU-IMI-PBD relaxes the stress significantly slower compared to both PU-PBD and PU-UPy-PBD. The inventors observed one long-term relaxation peak at 10.sup.3-10.sup.4 s which could explain the timescale of PU-IMI self-healing. Apparent activation energies estimated from relaxation spectra 110 and 146 kJ×mol.sup.−1 for TP and TS respectively could be defined by imine hydrolysis condensation or/and imine metathesis or/and transimination reactions. PU-UPy-IMI-PBD samples reviled the most complicated stress relaxation spectra. Spectra included two broad relaxation modes at 30-300 s like for PU-UPy-PBD and at 400-10.sup.4 s similar to PU-UPy-IMI-PBD combining both hydrogen bonds and dynamic covalent bonds reformation. Apparent activation energies for short relaxation modes were close to the ones for PU-UPy-PBDs. Activation energies for long time relaxation mode 3-5 times lower than for PU-IMI-PBD. Moreover, the inventors observed relatively intense long time peak at temperatures below T.sub.v. This relaxation allowed PU-UPy-IMI-PBD to save self-healing properties at lower temperatures. As a consequence, both urethane and UPy H-bonds and imine dynamic bonds synergistically interacted to facilitate self-healing. This cooperative behavior is expected to be general and of high benefit for the materials property, by reducing the activation energy necessary to heal polymer networks involving the poor kinetic lability of strong dynamic covalent bonds. This supports the generalization of the structure of claimed compounds.

[0179] Self-Adhesion of Thermoplastics and Thermosets

[0180] Adhesion between two pieces of Double Dynamic materials was examined using the JKR model of elastic contact. The extent of self-adhesion when exposed to either of the two stimuli, heat or solvent, was investigated by mounting two pieces of Double Dynamic material (9.3 mm×8.5 mm) onto two flat plates with 60 N of compressive force. Upon compressing the samples at 50° C. for 17 hours an adhesive force of 7×10.sup.5 N/m.sup.2 was observed for the material made from Polyvest®. With introduction of 2 drops of THF at the interface between the two samples, and compressing them for 5 hours at room temperature, an adhesive force of 2×10.sup.5 N/m.sup.2 was observed for the material made from Polyvest®.

Example 3—Preparation of a Di-Aldehyde Containing Compound Containing Said Supramolecular Moiety

[0181] ##STR00027##

[0182] Methylisocytosine (0.5 g, 1 eq) is added to IPDI (6.25 mL, 10 eq) in a flask, then the medium is placed under argon atmosphere. It is stirred and heated at 90° C. during 3 days. The resulting solution is then precipitated drop wise in cold hexane. A white precipitate is collected and washed by centrifugation. It is then dried and characterized by HRMS.

[0183] This approach allowed to prepare different isocyanates, without catalyst. Diisoyanates are then reacted with hydroxy-benzaldehyde to form the di-aldehyde containing compound containing said supramolecular moiety (UPy).

[0184] The principle of the chemical synthesis is as follows:

##STR00028##

[0185] Upy(IPDI) (0.5 g, 1 eq) and hydroxybenzaldehyde (0.52 g, 10 eq.) are added in a flask placed under argon atmosphere, then dissolved in 10 mL of anhydrous dichloromethane. Two drops of DBDL (dibutyltin dilauretate) are added to the medium to catalyse the reaction. The medium is stirred and heated at 60° C. all the night. The medium is then precipitated drop wise in cold ether. A white precipitate is collected and washed by centrifugation. It is then dried and characterized by HRMS.

[0186] The principle of the chemical synthesis is followed as previously describe.

[0187] This synthesis route has been tested on different isocyanates. The results obtained are summarized in the table 4 below, with the performance of each step, as well as the reference of the corresponding compound.

TABLE-US-00004 TABLE 4 Industrial Isocyanate I Diisocyanate Bis-aldéhyde HDI OK OK MDI f = 2 OK r = 82% — CL-1907 HMDI OK r = 25% — CL-1911 IPDI OK r = 99% OK r = 69% CL-1908 CL-1910 TDI OK r = 99% — CL-1909

[0188] This example supports and validates the synthetic route.

Example 4—Evaluation on Different Prepolymers (Elastomer Moities)

[0189] 4.1. Synthesis of the Polymer

[0190] A di-aldehyde containing compound containing said supramolecular moiety according to example 3 is reacted with a diamine prepolymer to synthesize the final polymer according to the invention.

[0191] The following chemical synthesis principle was performed:

##STR00029##

[0192] For this example, HDI diisocyanate, designated “BB(HDI)”, and provided by Novalix, was used.

[0193] 1st General Protocol:

[0194] In a two-neck round-bottom flask, 2 g of BB(HDI) are placed under argon and dissolved in 17 mL of anhydrous chloroform. The solution is heated and hexafluoropropanol (2% vol.) is added to promote dissolution of BB(HDI).

[0195] In another two-neck round-bottom flask, 2 g PPG(NH2) at 2000 g/mol are vacuum-dried for at least one hour (no more bubbles should appear). 5 mL of anhydrous chloroform is then added.

[0196] The BB(HDI) solution is then added to the prepolymer solution through the septum. The resulting mixture is then stirred for about 10 seconds and then poured into Teflon molds provided for this purpose.

[0197] These molds are then placed in a raised position in a crystallizer containing chloroform and covered with aluminum foil, so that a partially saturated atmosphere of chloroform is created in order to control solvent evaporation contained in the molds.

[0198] After this evaporation step, the material undergoes post-curing. It is placed in a vacuum oven for 5 hours at 50° C.

[0199] Used concentrations (varying slightly depending on the prepolymer and the starting di-aldehyde containing compound containing said supramolecular moiety) are therefore 1.2 g BB in 8 mL solvent, and 3 mL prepolymer in 3 mL solvent.

[0200] DSC Results of Different Compounds

TABLE-US-00005 Prepolymer (Elastomer Ref Isocyanate moiety) Tg (° C.) Tf (° C.) Tc (° C.) CL-1917 HDI PPG −56.1 72.3 62.4 101.2 CL-1920 IPDI PPG −49.6 CL-1923 HDI P(THF) −72 16 −19 CL-1925 HDI PPG −53 66 49 93 CL-1929 HDI PDMS

[0201] 4.2. Varying the Prepolymers (Elastomer Moities)

[0202] Different prepolymers, giving different physical properties to the final double-dynamic polymers, have been considered for this study. Compounds include polymers with amine chain ends to create imine bonds with the aldehyde ends of the di-aldehyde containing compound containing said supramolecular moiety. Poly(butadiene) has already been studied.

TABLE-US-00006 Poly(butadiene) [00030] Poly(propylene glycol) [00031] Poly(dimethylsiloxane) [00032] Poly(tetrahydrofurane) [00033]

[0203] All these prepolymers have an average molecular weight of 2000 g.Math.mol-1. Most of the tests were performed on poly(propylene glycol) (PPG), supplied by BASF as Baxxodur EC 303. PDMS(NH2) was supplied by Sigma-Aldrich.

[0204] Poly(THF), initially functionalized by —OH end chains, was modified with —NH2 end groups, before use, following a procedure similar to the one used for poly(butadiene).

[0205] All the prepolymers tested lead to the production of a satisfying polymer (bubble-free, transparent). This study suggests that different prepolymers (elastomer moieties) can be used and selected according to the final properties expected.

Example 5—Recyclable Properties of Polymers According to the Invention

[0206] Recyclability of Thermoplastics and of Thermosets

[0207] THF (6 mL) was added to the sliced polymer (500 mg) in two portions with 90 minutes delay to reach full swelling. Then, trifluoroacetic acid (60 μL) and 1 drop of water was added and the mixture was left to shake for 2 hours. Then a NaHCO.sub.3 brine solution (2 mL) was added. The biphasic mixture was shaken for 2 hours to reach pH=7 for the aqueous layer. The THF layer was dried and pipetted into the mold to evaporate the solvent at room temperature overnight. Then molds were heated at 50° C. in vacuum for 8 hours. The mechanical properties of the recycled material were then further evaluated according to mechanical experiments (DMTA, elongation until break) described previously.

[0208] All polymers proved to be recyclable according to this procedure.