Method for producing functionalised telechelic oligomers

Abstract

This invention relates to a method for producing functionalized telechelic oligomers, comprising two steps. The first step relates to bringing a raw material comprising at least one high-molecular-weight polymer comprising at least two unsaturations, into contact with a solution comprising at least one metathesis catalyst and at least one functionalizing agent. The second step relates to the separation of the functionalized telechelic oligomers produced by the metathesis reaction in ionic liquid medium of the first step.

Claims

1. Method for producing functionalized telechelic oligomers, comprising: a) bringing a raw material consisting of at least one high-molecular-weight polymer comprising at least two unsaturations, into contact with a solution comprising at least one ionic liquid, at least one metathesis catalyst and at least one functionalising agent chosen from hydrogenocarbonated molecules having a symmetrical disubstituted carbon-carbon double bond and two functions having a general formula: ##STR00006## wherein, R can be a group: COR, R being chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl; COOR, R being chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, methyl-1,3-dioxolanone, methyl-oxirane; OR, R being chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, methyl-1,3-dioxolanone, methyl-oxirane; NRR, R and R being identical or different, each one chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl, acetyl, tert-butyl-acetyl; [N.sup.+RRR,X.sup.], R, R, R being identical or different and each one chosen from a group comprising substituted or unsubstituted alkyl, substituted or unsubstituted aryl and X.sup. being an anion chosen from the group comprising fluoride, chloride, iodide, bromide, tosylate, triflate; SR, R being chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl; CN; C(N)R, R being chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl; SO.sub.2R, R being chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl; SO.sub.3R, R being chosen from a group comprising hydrogen, substituted or unsubstituted alkyl, substituted or unsubstituted aryl; NO.sub.2; and b) the separation of the functionalized telechelic oligomers produced by the metathesis reaction in an ionic liquid medium of the step a).

2. Method according to claim 1, wherein said raw material is put into solution with an ionic liquid before it is brought into contact with the solution comprising a metathesis catalyst and a functionalising agent.

3. Method according to claim 1, wherein the raw material is chosen from the group comprising ethylene-propylene-diene monomer (EPDM), styrene-ethylene-butadiene-styrene (SEBS), styrene butadiene rubber (SBR), acrylonitrile-butadiene (Nitrile Butadiene Rubber NBR), partially hydrogenated acrylonitrile-butadiene (Hydrogenated Nitrile-Butadiene Rubber HNBR), Styrene-Butadiene-Styrene (SBS), thermoplastic elastomer (Thermo-Plastic Elastomer Styrenic TPE), styrenic block copolymer (Thermo-Plastic Elastomer Styrenic TPS), a styrenic block copolymer selected from the group comprising Styrene-Isoprene-Styrene (SIS), Styrene-Ethylene-Butylene-Styrene (SEBS), Styrene-Ethylene-Propylene-Styrene (SEPS), and Styrene-Ethylene-Ethylene/Propylene-Styrene (SEEPS).

4. Method according to claim 1, wherein the metathesis catalyst is chosen from a group comprising a Grubbs I catalyst, a Grubbs II catalyst, a Hoveyda-Grubbs I catalyst and a Hoveyda Grubbs II catalyst.

5. Method according to claim 1, wherein the functionalising agent is chosen from the group comprising cis-but-2-ene-diacetate, cis-but-2-ene-diketone, cis-but-2-ene-diol, and cis-but-2-ene-diamine.

6. Method according to claim 1, wherein the ionic liquid is trihexyl(tetradecyl)phosphonium chloride or N,N-dioctylimidazolium bromide ([DOIM][Br]).

7. Method according to claim 1, wherein the functionalising agent is cis-but-2-ene-diacetate, the metathesis catalyst is Grubbs II and the ionic liquid is trihexyl(tetradecyl)phosphonium chloride.

8. Method according to claim 1, wherein the functionalising agent is cis-but-2-ene-diacetate, the metathesis catalyst is Hoveyda-Grubbs II and the ionic liquid is N,N-dioctylimidazolium bromide.

9. Method according to claim 1, comprising a step wherein the metathesis catalyst contained in the liquid medium resulting from the separation of the step b) is recycled.

10. Composition of functionalized telechelic oligomers able to be produced by the method according to claim 1, characterized in that the oligomers have a net functionality of 2.

11. Method according to claim 1, wherein the raw material is a waste material containing rubber, with said method being simultaneously a method for degrading and for recycling said waste material and a method for producing telechelic oligomers.

12. Method according to claim 1, wherein the raw material is a tire waste.

Description

BRIEF DESCRIPTION OF THE FIGURES

(1) FIG. 1 is a reaction scheme of an example of preparing functionalised telechelic oligomers, according to the invention.

(2) FIG. 2 is a diagram of an example of preparing telechelic oligomers according to the invention, wherein the metathesis catalyst is recycled.

EXAMPLES

(3) This invention shall be better understood when reading the following examples which represent the invention in a non-limiting manner.

(4) Material and Methods

(5) The NMR spectra were recorded on a Bruker Avance Spectrometer device for the NMR of the proton (500 MHz). The chemical displacements () are given in ppm with for reference tetramethylsilane (TMS). The average molecular weight (Mn) and the polydiversity index are measured via steric exclusion chromatography (SEC) with a Waters system (pump 515 hplc, differential refractometer 410 and a photodiode detector) with two Styragel Waters columns (HR5E THF 7.8300 mm from 2000 to 410.sup.6 g.Math.mol-1 and HR1 THF 7.8300 mm from 100 to 4000 g.Math.mol-1). The steric exclusion chromatography was carried out at 35 C. with as an eluent tetrahydrofurane at a flow rate of 1 mL/min. The calibration of the steric exclusion chromatography was carried out using standard linear polystyrenes (ranging from 1.2710.sup.3 g/mol to 3.0410.sup.6 g/mol). The molecular weight of the polyisoprene was corrected by the Benoit factor of 0.67 in accordance with the formula of the reference Busnel et al., Polymer, 1982, 23, 137. The high-molecular-weight cis-polyisoprene was used without prior purification and cryogenically ground.

(6) All of the reactions were carried out in Schlenk tubes in a nitrogen atmosphere. The acetone is distilled on anhydrous potassium carbonate under argon. The starting products come from Sigma Aldrich and were used without prior purification. The 2-(2-propoxy)styrene, the N,N-dioctylimidazolium bromide and the cis-1,4-diacetoxy-2-butene were prepared as described in the literature (Garber et al., J. Am. Chem. Soc., 2000, 122, 8168; Livi et al., Chem. Commun., 2001, 16, 1466; Otaka et al., Chem. Commun., 2003, 15, 1834).

Example 1

(7) ##STR00004##

(8) Material and Methods

(9) In a 100 mL Schlenk tube, 0.35 g (5,147 mmol) of polyisoprene (natural rubber) are introduced into 8 mL of a purified ionic liquid (Cyphos=101), corresponding to the mixture A. The mixture is stirred in a vacuum then placed under nitrogen at 47 C. for 15 minutes. In a 25 mL Schlenk tube are added 43.6 mg (0.0513 mmol) of Grubbs II catalyst, 17.5 mg (0.1011 mmol) of functionalising agent cis-but-2-ene-diacetate (DAB) and 3 mL of purified ionic liquid (Cyphos=101), constituting the mixture B. The mixture is stirred in a vacuum then placed under nitrogen at ambient temperature for 40 minutes. The mixtures A and B are then brought together then stirred at 47 C. for 14 h. The reaction is then stopped by adding ethyl vinyl ether still under nitrogen. Then 70 mL of anhydrous acetone are added allowing for the precipitation of the functionalised telechelic oligomers. The oligomers are then separated from the reaction medium and washed several times with acetone. The functionalised telechelic oligomers are then vacuum dried and are obtained with a yield of 97%.

(10) Results

(11) The results provided in tables 1 to 3 give the number average molecular weight (M.sub.n) and the weight average molecular weight (M.sub.w) determined by steric exclusion chromatography of the oligomers obtained as well as their polydispersity (M.sub.w/M.sub.n) and the yield from the reaction for the different reaction conditions tested.

(12) Table 1 shows the results for the reactions carried out with different concentrations in polyisoprene.

(13) TABLE-US-00001 TABLE 1 Influence of the concentration in polyisoprene in the degradation reaction [PI] M.sub.n SEC M.sub.w SEC Entry (moles/L) (g/mol) (g/mol) PDI Yield % 1 0.46 39.000 86.000 2.16 98 2 0.57 40.000 81.000 1.99 97 3 1.02 38.000 88.000 2.26 96 4 1.71 35.000 71.000 1.99 97 5 2.57 32.000 64.000 2.00 97 6 5.14 26.000 48.000 1.83 97

(14) Table 2 shows the results obtained for reaction times ranging from 3 to 43 hours.

(15) TABLE-US-00002 TABLE 2 Influence of reaction time in the reaction Reaction M.sub.n SEC M.sub.w SEC Entry time (h) (g/mol) (g/mol) PDI Yield % 1 3 41.000 85.000 2.05 98 2 14 36.000 73.000 2.00 97 3 43 39.000 65.000 2.03 99

(16) Table 3 shows the results obtained for reaction times ranging from 0.5 to 6 hours for two concentrations of starting polyisoprene of 1.02 g.Math.mol.sup.1 (conditions a) and 5.14 g.Math.mol.sup.1 (conditions b).

(17) TABLE-US-00003 TABLE 3 Change in the molar weights M.sub.n and M.sub.w as a function of reaction time Reaction [PI] M.sub.n SEC M.sub.w SEC Entry time (h) (moles/L) (g/mol) (g/mol) PDI Yield % 1.sup.a 0.5 1.02 64.000 142.000 2.16 97 2.sup.a 1 1.02 46.000 97.000 2.07 97 3.sup.a 2 1.02 37.000 74.000 1.97 94 4.sup.a 3 1.02 38.000 88.000 2.26 96 1.sup.b 0.5 5.14 91.000 239.000 2.62 98 2.sup.b 1 5.14 57.000 129.000 2.24 97 3.sup.b 2 5.14 35.000 72.000 2.03 95 4.sup.b 3 5.14 26.000 48.000 1.83 97 5.sup.b 6 5.14 24.000 44.000 1.87 99

(18) NMR of the Proton of the Obtained Oligomers:

(19) NMR .sup.1H (CDCl.sub.3, 500 MHz): (ppm) 1.70-1.60 (m, 3H); 2.12-1.95 (m, 4H), 4.50 (m, 2H); 4.59 (m, 2H); 5.34-5.44 (m, 1H); 5.53-5.63 (m, 1H); 5.71-5.83 (m, 1H).

Example 2

(20) ##STR00005##

(21) In a 100 mL Schlenk tube, 32.1 mg (0.051 mmol) of Hoveyda-Grubbs II catalyst, 17.6 mg (0.1011 mmol) of functionalising agent cis-but-2-ene-diacetate (DAB) and 1 mL of purified ionic liquid ([DOIM][Br]) are mixed then placed under argon a stirred 40 min at ambient temperature. Then 350 mg (5.14 mmol) of natural rubber are added and the mixture is stirred for 3 hours at 50 C. under nitrogen. The reaction is then stopped by adding 10.2 mg (0.061 mmol) of 2-(2-propoxy)styrene still under nitrogen. Then 50 mL of anhydrous acetone are added allowing for the precipitation of the functionalised telechelic oligomers. The oligomers are then separated from the reaction medium and washed several times with acetone then vacuum dried and obtained with a yield of 96%.

(22) The reaction mixture comprising the catalyst, the acetone, the ionic liquid and the 2-(2-propoxy)styrene is transferred into a flask and the acetone is evaporated in a vacuum. The resulting mixture is extracted with 5 mL of anhydrous pentane in order to eliminate the 2-(2-propoxy)styrene and vacuum dried for 15 minutes.

(23) The reaction medium can then again be used for another reaction cycle after adding the functionalising agent and stirring for 40 minutes followed by the adding of rubber.

(24) Results

(25) Table 4 indicates the molecular weights by number and by weight of the oligomers obtained as well as the yield of the reaction in the ionic liquid medium ([DOIM][Br]) recycled from 1 to 6 times.

(26) TABLE-US-00004 TABLE 4 Recycling of the catalyst (Hoveyda Grubbs II) in the degradation reaction of the polyisoprene in the [DOIM][Br] M.sub.n SEC M.sub.w SEC Entry Cycle (g/mol) (g/mol) PDI Yield % 1 0 23.000 44.000 1.89 95 2 1 52.000 119.000 2.25 97 3 2 59.000 138.000 2.32 96 4 3 64.000 167.000 2.58 97 5 4 70.000 148.000 2.09 97 6 5 79.000 187.000 2.34 98 7 6 113.000 330.000 2.91 97