Catalyst system containing a metathesis catalyst and at least one phenolic compound and a process for metathesis of nitrile-butadiene rubber (NBR) using the catalyst system

Abstract

The present invention relates to a catalyst system containing a metathesis catalyst containing at least one N-heterocyclic carbene ligand and at least one phenolic compound and to a process for performing the metathesis on nitrile rubbers for reducing their molecular weight using a metathesis catalyst containing at least one N-heterocyclic carbene ligand (NHC ligand) and at least one phenolic compound.

Claims

1. A catalyst system for reducing the molecular weight of nitrile rubbers by subjecting the nitrile rubber to a metathesis reaction, the catalyst system containing: (i) a metathesis catalyst containing at least one NHC ligand selected from the group consisting of: a catalyst of general formula (A), ##STR00051## wherein M represents osmium or ruthenium, X1 and X2 are identical or different and represent halogen, L represents identical or different ligands, wherein at least one ligand L represents an N-heterocyclic carbene ligand, R are identical or different and represent hydrogen, alkyl, cycloalkyl, alkenyl, alkynyl, aryl, carboxylate, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulfonyl, or alkylsulfinyl, wherein all of these radicals may each optionally be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl radicals, or alternatively the two R radicals together with the common carbon atom to which they are bonded are bridged to form a cyclic group which may be aliphatic or aromatic in nature, is optionally substituted and may contain one or more heteroatoms; a catalyst of general formula (B), ##STR00052## wherein M represents ruthenium or osmium, X.sup.1 and X.sup.2 are identical or different and represent halogen, Y represents oxygen (O), sulfur (S), an N—R.sup.1 radical or a P—R.sup.1 radical, wherein R.sup.1 represents an alkyl, cycloalkyl, alkenyl, alkynyl, aryl, alkoxy, alkenyloxy, alkynyloxy, aryloxy, alkoxycarbonyl, alkylamino, alkylthio, arylthio, alkylsulfonyl or alkylsulfinyl radical, each of which may optionally be substituted by one or more alkyl, halogen, alkoxy, aryl or heteroaryl radicals, R.sup.2, R.sup.3, R.sup.4 and R.sup.5 are identical or different and represent hydrogen, organic or inorganic radicals, R.sup.6 is hydrogen or an alkyl, alkenyl, alkynyl or aryl radical and L is a ligand as defined for the formula (A); and (ii), as a co-activator, at least one phenolic compound of general formula (Z2) ##STR00053## wherein n has a value of 2, 3, or 4 and R1 each independently represents (C.sub.1-C.sub.18)-alkyl, (C.sub.3-C.sub.18)-cycloalkyl, (C.sub.6-C.sub.10)-aryl, (C.sub.6-C.sub.24)-alkaryl, (C.sub.6-C.sub.24)-aralkyl, —N(R.sup.2).sub.2 where R.sup.2 is H or (C.sub.1-C.sub.18)-alkyl, —NO.sub.2, (C.sub.1-C.sub.18)-alkoxy, —CHO, —CN, (C.sub.3-C.sub.10)-heteroaryl, —COO(R.sup.2) where R.sup.2 is H or (C.sub.1-C.sub.18-alkyl, —CO—O—CO(R.sup.2) where R.sup.2 is H or (C.sub.1-C.sub.18)-alkyl, —(CH.sub.2).sub.n—COO—(CH.sub.2).sub.n—H, wherein n are each independently 1 to 18, —COX where X is Cl or Br, —CON(R.sup.2).sub.2 where R.sup.2 is H or (C.sub.1-C.sub.18)-alkyl, or a halogen and B represents an alkanediyl group.

2. The catalyst system of claim 1, wherein the metathesis catalyst is selected from the group consisting of: dichloro(fluorenylidene)(1,3-dimesityldihydroimidazolylidene)(triphenylphosphino)ruthenium, 1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(o-isopropoxyphenylmethylene)ruthenium, [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)bis(3-bromopyridine)ruthenium(II), and 1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)(2-isopropoxy-5-nitrobenzylidene)ruthenium(II)chloride.

3. The catalyst system of claim 1 wherein the phenolic compound of general formula (Z1) is selected from the group consisting of: 2,2′-methylene-bis(4-methyl-6-tert-butylphenol), and 2,2′-methylenebis(4-methyl-6-nonylphenol).

4. The catalyst system of claim 1, wherein the molar ratio of metathesis catalyst to phenolic compound of general formula (Z2)=1:(0.01-1000).

5. A process of performing a metathesis of nitrile rubber, the process comprising the use of the catalyst system of claim 1.

6. A process of reducing the molecular weight of nitrile rubbers, in which a nitrile rubber is subjected to a metathesis reaction in the presence of the catalyst system of claim 1 and wherein the process is carried out in a reaction mixture comprising the catalyst system and the nitrile rubber.

7. The process of claim 6, wherein the amount of metathesis catalyst is 1 to 1000 ppm of noble metal, based on the nitrile rubber subjected to the metathesis reaction.

8. The process of claim 6, wherein the amount of phenolic compound of general formula (Z2) is 0.0001 phr to 5 phr, based on the nitrile rubber subjected to the metathesis reaction.

9. The process of claim 6, wherein the metathesis reaction is performed in the absence or in the presence of a co-olefin.

10. The process of claim 6, wherein the metathesis reaction is carried out in an organic solvent.

11. The process of claim 6, wherein the concentration of the nitrile rubber in the reaction mixture is in the range from 1% to 25% by weight, based on the reaction mixture.

12. The process according to claim 6, wherein the metathesis reaction is carried out at a temperature in the range from 10° C. to 150° C.

13. A nitrile rubber formed by the process of claim 6, wherein the amount of phenolic compound according to formula (Z2) is 0.0001 phr to 5 phr, based on the total amount of nitrile rubber subjected to the metathesis reaction, wherein the nitrile rubber formed has a Mooney viscosity (ML 1+4 at 100° C.) from 5 to 35 Mooney units.

14. The nitrile rubber of claim 13, having a molecular weight Mw in the range of 10 000 g/mol to 100 000 g/mol.

15. The nitrile rubber of claim 13, having a polydispersity index (PDI=Mw/Mn) in the range of 1.4 to 4.0, wherein Mw is the weight-average molecular weight and Mn is the number-average molecular weight.

16. The catalyst system of claim 1, wherein the metathesis catalyst is selected from the group consisting of: dichloro(fluorenylidene)(1,3-dimesityldihydroimidazolylidene)(triphenylphosphino)ruthenium, 1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)dichloro(o-isopropoxyphenylmethylene)ruthenium, [1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene]dichloro(phenylmethylene)bis(3-bromopyridine)ruthenium(II), and, 1,3-bis(2,4,6-trimethylphenyl)-2-imidazolidinylidene)(2-isopropoxy-5-nitrobenzylidene)ruthenium(II)chloride; and the phenolic compound of general formula is selected from the group consisting of: 2,2′-methylene-bis(4-methyl-6-tert-butylphenol), and 2,2′-methylenebis(4-methyl-6-nonylphenol).

Description

EXAMPLES

(1) Materials Employed

(2) The metathesis reactions (molecular weight degradation reactions) described in the following test series were performed using a nitrile rubber having the following characteristics: Acrylonitrile content: 34.3% by weight; Mooney viscosity (ML 1+4 @100° C.): 33 Mooney units; residual moisture: 1.0% by weight.

(3) TABLE-US-00001 Metathesis catalysts Grubbs II Benzylidene[1,3-bis(2,4,6-trimethylphenyl)-2- catalyst imidazolidinylidene]dichloro(tricyclohexyl- phosphine)ruthenium (C.sub.46H.sub.65Cl.sub.2N.sub.2PRu; M = 848.97 g/mol) (Umicore) Grubbs III [1,3-Bis(2,4,6-trimethylphenyl)-2- catalyst imidazolidinylidene]dichloro(phenylmethylene)bis(3- bromopyridine)ruthenium(II) (C.sub.38H.sub.40Br.sub.2Cl.sub.2N.sub.4Ru; M = 884.54 g/mol); (Umicore) Grubbs- 1,3-Bis(2,4,6-trimethylphenyl)-2- Hoveyda imidazolidinylidene)dichloro(o- II catalyst isopropoxyphenylmethylene)ruthenium (C.sub.31H.sub.38Cl.sub.2N.sub.2ORu; M = 626.62 g/mol) (Umicore) M41 catalyst [1,3-Bis(2,4,6-trimethylphenyl)-2- imidazolidinylidene]chloro[2-[[(4- methylphenyl)imino]methyl]-4-nitrophenolato](3- phenyl-1H-inden-1-ylidene)ruthenium (C.sub.50H.sub.47ClN.sub.4O.sub.3Ru; M = 888.46 g/mol) (Umicore) Grela catalyst 1,3-Bis(2,4,6-trimethylphenyl)-2- imidazolidinylidene)(2-isopropoxy-5- nitrobenzyliden)ruthenium(VI)chloride (C.sub.31H.sub.37Cl.sub.2N.sub.3O.sub.3Ru; M = 671.62 g/mol) (Apeiron) Fluorenylidene Dichloro(fluorenylidene)(1,3- K2 catalyst dimesityldihydroimidazolylidene)(triphenyl- phosphino)ruthenium (C.sub.52H.sub.49Cl.sub.2N.sub.2PRu; M = 904.92 g/mol; prepared according to DE-A-102007039695)

(4) TABLE-US-00002 Phenolic compounds Vulkanox ® 2,2′-Methylene-bis(4-methyl-6-tert-butylphenol); (M = BKF 340.6 g/mol; CAS-No.: 000119-47-1; C.sub.23H.sub.32O.sub.2) (LANXESS) Vulkanox ® 2,6-Di-tert-butyl-4-methylphenol (M = 220.4 g/mol; BHT CAS-No.: 000128-37-0; C.sub.15H.sub.24O) (LANXESS) Irganox ® Octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenyl) (M = 1076 530.86 g/mol; CAS-No.: 2082-79-3; C.sub.35H.sub.62O.sub.3) (BASF) Irganox ® 2-Methyl-4,6-bis((octylthio)methyl)phenol (M = 424.75 1520 g/mol; CAS-No.: 110553-27-0; C.sub.25H.sub.44OS.sub.2) (BASF) Naugawhite ® 2,2′-Methylenebis(4-methyl-6-nonylphenol) (M = 480.76 g/mol; CAS-No.: 7786-17-6; C.sub.33H.sub.52O.sub.2) (Addivant) Phenol Hydroxybenzene (M = 94.11 g/mol; CAS-No.: 108-95-2; C.sub.6H.sub.5OH) (Merck Millipore) 2,2′-Bisphenol Bis(2-hydroxyphenyl)methane (M = 200.24 g/mol; CAS-No.: 1333-16-0; C.sub.13H.sub.12O.sub.2) (Sigma Aldrich) Bisphenol F Bis(4-hydroxyphenyl)methane (M = 200.24 g/mol; CAS-No.: 620-92-8; C.sub.13H.sub.12O.sub.2) (Sigma Aldrich)

(5) Determination of Molecular Weight

(6) The molecular weights obtained in the metathesis degradation reaction were determined by gel permeation chromatography (GPC). Before performing the GPC analysis the solutions were in each case filtered using a 0.2 μm syringe filter made of Teflon (Chromafil PTFE 0.2 mm; Machery-Nagel). This was followed by GPC analysis using a Waters 510 instrument. Analysis employed a combination of a pre-column (PL Guard from Polymer Laboratories) and 2 Resipore columns (300×7.5 mm, pore size 3 μm) from Polymer Laboratories. Calibration of the columns was carried out with linear polystyrene having molar masses of 960 to 6×105 g/mol from Polymer Standards Services. The detector used was a Waters RI detector (Waters 410 Differential Refractometer). Analysis was performed at a flow rate of 1.0 mL/min at 80° C. using N,N′-dimethylacetamide as eluent. Evaluation of the GPC curves was carried out with software from Polymers Laboratories (Cirrus Multi Version 3.0).

(7) Purification According to Protocol 1

(8) 30 g of NBR were dissolved in 270 mL of toluene and the obtained solution was poured into a beaker filled with 700 mL of methanol with stirring over 3 minutes. The methanol from the thus-precipitated material was squeezed out on an aluminum plate and the solid was redissolved in 270 ml of toluene on a laboratory shaker. Precipitation was repeated twice. After the third reprecipitation the material was dissolved in toluene, optionally admixed with the relevant phenolic compound and the toluene removed at 60° C. using a rotary evaporator (10 mbar, about 30 minutes). In order to remove residual methanol entirely the solid was dissolved in 500 g of monochlorobenzene (MCB) and concentrated to afford a 10% solution using a rotary evaporator. The solution was employed directly in the metathesis.

(9) Purification According to Protocol 2

(10) 30 g of NBR were dissolved in 270 mL of toluene and the obtained solution was poured into a beaker filled with 700 mL of methanol with stirring over 3 minutes. The methanol from the thus-precipitated material was squeezed out on an aluminum plate and the solid was redissolved in 270 ml of toluene on a laboratory shaker. Precipitation was repeated twice. The relevant phenolic compound was added to a solution of the precipitated material before methanol and toluene were removed. After the third reprecipitation the material was dried to a constant mass in a Teflon-coated bowl at room temperature in a vacuum drying cabinet. Analysis revealed a residual methanol content of 20 ppm. The material was employed directly in the metathesis.

(11) Preparation of the Catalyst Solution for the Metathesis with Metathesis Catalyst

(12) A fresh batch of catalyst solution was made up before each experiment. In a 100 mL Schlenk flask 25 mL of MCB were degassed and inertized with argon three times. The relevant amounts of metathesis catalyst were added under an argon countercurrent and the obtained solution was once again degassed and inertized with argon to ensure a complete absence of oxygen.

(13) Metathesis of NBR without Addition Vs. with Addition of Vulkanox® BKF

(14) In a 250 mL Schlenk flask fitted with a reflux cooler and a magnetic stirrer 5 g of the NBR purified according to protocol 1 were dissolved in 45 g of MCB (10% solution) and the obtained solution was degassed and inertized with argon. 8 phr of 1-dodecene were added countercurrently and the solution optionally brought to reaction temperature. 0.5 mL of the fresh catalyst solution were added, corresponding to an amount of 0.005 phr/29 μmol of Grubbs II catalyst. The reaction mixture was stirred at 20° C./60° C. for 4 hours. Respective 2 mL samples were removed after reaction times of 30, 60, 120 and 240 minutes and, in a screw top vial, reacted with 0.5 mL of ethyl vinyl ether to terminate the metathesis reaction. The samples were analyzed by GPC. The results are shown in tables 1.1 to 1.4.

(15) Tables 1.1-1.4. Metathesis of NBR with 0.005 Phr of Grubbs II Catalyst with and without Addition of 0.11 Phr of Phenolic Compound (Vulkanox® BKF) at 20° C. and 60° C. (Mw.sup.n=Normalized to Initial Molecular Weight)

(16) TABLE-US-00003 TABLE 1.1 20° C.; without addition t [min] Mn Mw PDI M.sub.W.sup.n 0 85.876 254.612 3.0 1.00 30 79.806 236.365 3.0 0.93 60 78.630 232.389 3.0 0.91 120 77.935 232.538 3.0 0.91 240 77.108 229.745 3.0 0.90

(17) TABLE-US-00004 TABLE 1.2 60° C.; without addition Mn Mw PDI M.sub.W.sup.n 85.876 254.612 3.0 1.00 77.874 225.693 2.9 0.89 78.090 225.603 2.9 0.89 78.124 228.213 2.9 0.90 77.793 230.679 3.0 0.91

(18) For metathesis reactions without addition of phenolic compounds only a very low degradation of the molecular weight (Mw) is observed both at low temperatures of 20° C. (table 1.1) and at high temperatures of 60° C. (table 1.2).

(19) TABLE-US-00005 TABLE 1.3 20° C.; with addition t [min] Mn Mw PDI M.sub.W.sup.n 0 84.100 258.017 3.1 1.00 30 77.015 224.554 2.9 0.87 60 72.366 201.865 2.8 0.78 120 62.638 158.428 2.5 0.61 240 29.912 61.908 2.1 0.24

(20) TABLE-US-00006 TABLE 1.4 60° C.; with addition Mn Mw PDI M.sub.W.sup.n 84.100 25.8017 3.1 1.00 29.880 61.533 2.1 0.24 29.912 61.287 2.0 0.24 29.925 61.203 2.0 0.24 29.803 61.055 2.0 0.24

(21) Addition of 0.11 phr of phenolic compound (Vulkanox® BKF; table 1.3 and 1.4) results in a substantially greater degradation of the molecular weight (Mw) than in the case of metathesis reactions without addition of phenolic compounds (tables 1.1 and 1.2).

(22) The metathesis reaction proceeds faster at 60° C. (table 1.4) than at 20° C. (table 1.3).

(23) In a 250 mL Schlenk flask fitted with a reflux cooler and a magnetic stirrer 5 g of the NBR purified according to protocol 2 were dissolved in 45 g of MCB (10% solution) and the obtained solution was degassed and inertized with argon. 8 phr of 1-dodecene were added countercurrently and the solution optionally brought to reaction temperature. 0.5 mL of the fresh catalyst solution was added, corresponding to an amount of 0.005 phr/29 μmol of Grubbs II catalyst. The reaction mixture was stirred for 4 hours at 20° C. Respective 2 mL samples were removed after reaction times of 30, 60, 120 and 240 minutes and, in a screw top vial, reacted with 0.5 mL of ethyl vinyl ether to terminate the metathesis reaction. The samples were analyzed by GPC. The results are shown in tables 1.5 and 1.6.

(24) Tables 1.5-1.6. Metathesis of NBR with 0.005 Phr of Grubbs II Catalyst with and without Addition of 0.11 Phr of Phenolic Compound (Vulkanox® BKF) at 20° C. (Pure Material Dried Overnight at Room Temperature in HV Drying Cabinet, 20 ppm MeOH):

(25) TABLE-US-00007 TABLE 1.5 20° C.; without addition t [min] Mn Mw PDI M.sub.W.sup.n 0 90.326 306.395 3.4 1 30 84.076 269.406 3.2 0.88 60 84.451 268.663 3.2 0.88 120 83.579 270.823 3.2 0.88 240 85.242 276.162 3.2 0.90

(26) TABLE-US-00008 TABLE 1.6 20° C.; with addition Mn Mw PDI M.sub.W.sup.n 90.326 306.395 3.4 1 84.829 275.479 3.2 0.90 80.841 247.189 3.1 0.81 66.941 187.027 2.8 0.61 55.856 139.043 2.5 0.45

(27) Irrespective of the method of purification of the NBR intensified degradation of the molecular weight (Mw) occurs only when the catalyst system contains not only the metathesis catalyst (Grubbs II catalyst) but also at least one phenolic compound (Vulkanox® BKF).

(28) Metathesis of NBR with Different Amounts of Added Vulkanox® BKF

(29) In a 250 mL Schlenk flask fitted with a reflux cooler and a magnetic stirrer 5 g of the NBR purified according to protocol 1 and admixed with Vulkanox® BKF were dissolved in 45 g of MCB and the obtained solution degassed and inertized with argon. The added amounts of Vulkanox® BKF are shown in table 2 below. 8 phr of 1-dodecene and 0.5 ml of the fresh catalyst solution (corresponding to 0.005 phr/0.29 μmol of Grubbs II catalyst) were added countercurrently. The reaction mixture was stirred for 4 hours. Respective 2 mL samples were removed after reaction times of 30, 60, 120 and 240 minutes and, in a screw top vial, reacted with 0.5 mL of ethyl ether to terminate the metathesis reaction. The samples were analyzed by GPC. For comparison a sample of the non-pre-treated NBR was reacted with the catalyst under identical conditions. The ratio of nitrile groups in the nitrile rubber to phenolic compound (Vulkanox® BKF) is shown as CN/BKF.

(30) TABLE-US-00009 TABLE 2 Metathesis of NBR with Grubbs II catalyst (0.005 phr) and different amounts of Vulkanox ® BKF (Mw.sup.n = normalized to initial molecular weight) BKF/ NBR Grubbs II Vulkanox ® BKF Grubbs II CN/BKF No. [m/g] [n/μmol] [phr] [μmol] [mol/mol] [mol/mol] 2.1 5 0.29 0.22 32.30 111 1.000 2.2 5 0.29 0.04 5.87 20 5.000 2.3 5 0.29 0.02 2.94 10 10.000 2.4 5 0.29 0.004 0.59 2.0 50.000 2.5 5 0.29 0.002 0.29 1.0 100.000 2.6 5 0.29 0.0008 0.12 0.4 250.000

(31) TABLE-US-00010 TABLE 2.1 t [min] Mn Mw PDI M.sub.W.sup.n 0 90.876 315.268 3.5 1 30 79.138 249.987 3.2 0.79 60 71.931 206.205 2.9 0.65 120 58.057 148.123 2.6 0.47 240 57.165 144.855 2.5 0.46

(32) TABLE-US-00011 TABLE 2.2 t [min] Mn Mw PDI M.sub.W.sup.n 0 91.644 301.850 3.3 1 30 85.329 261.504 3.1 0.87 60 75.606 217.827 2.9 0.72 120 60.743 149.808 2.5 0.50 240 43.381 94.999 2.2 0.31

(33) TABLE-US-00012 TABLE 2.3 t [min] Mn Mw PDI M.sub.W.sup.n 0 88.404 300.869 3.4 1 30 81.515 268.850 3.3 0.89 60 75.145 231.994 3.1 0.77 120 62.300 164.555 2.6 0.55 240 46.016 106.782 2.3 0.35

(34) TABLE-US-00013 TABLE 2.4 t [min] Mn Mw PDI M.sub.W.sup.n 0 90.836 310.781 3.4 1 30 82.139 257.614 3.1 0.83 60 74.669 217.474 2.9 0.70 240 49.297 113.840 2.3 0.37

(35) TABLE-US-00014 TABLE 2.5 t [min] Mn Mw PDI M.sub.W.sup.n 0 87.895 301.258 3.4 1 30 79.458 254.116 3.2 0.84 60 74.752 223.595 3 0.74 120 63.386 171.361 2.7 0.57 240 49.062 118.342 2.4 0.39

(36) TABLE-US-00015 TABLE 2.6 t [min] Mn Mw PDI M.sub.W.sup.n 0 89.327 305.546 3.4 1 30 85.725 280.547 3.3 0.92 60 82.933 261.929 3.2 0.86 120 75.399 218.833 2.9 0.72 240 66.269 176.212 2.7 0.58

(37) The greater the amount of added Vulkanox® BKF the faster the degradation of the molecular weight of the nitrile rubber.

(38) Metathesis of NBR with Addition of Different Phenolic Compounds

(39) In a 250 mL Schlenk flask fitted with a reflux cooler and a magnetic stirrer 5 g of the NBR purified according to protocol 2 and dried were dissolved in 45 g of MCB and admixed with the relevant phenolic compound. The respective phenolic compounds and the amounts added in each case are shown in table 3 which follows. The amounts of phenolic compound were chosen such that the number of OH groups is constant. The thus-obtained solution was degassed and inertized with argon. 8 phr of 1-dodecene and 0.5 ml of the fresh catalyst solution (corresponding to 0.005 phr of Grubbs II catalyst) were added countercurrently. The reaction mixture was stirred for 4 hours. Respective 2 mL samples were removed after reaction times of 30, 60, 120 and 240 minutes and, in a screw top vial, reacted with 0.5 mL of ethyl ether to terminate the metathesis reaction. The samples were analyzed by GPC.

(40) TABLE-US-00016 TABLE 3 Metathesis of NBR with Grubbs II catalyst and different phenolic compounds NBR Grubbs II Phenolic compound No. [g] [μmol] Designation [phr] [μmol] 3.0 5 0.29 — — — 3.1 5 0.29 Vulkanox ® BKF 0.11 16 3.2 5 0.29 Vulkanox ® BHT 0.142 32 3.3 5 0.29 Irganox ® 1076 0.343 32 3.4 5 0.29 Irganox ® 1520 0.274 32 3.5 5 0.29 Naugawhite ® 0.155 16 3.6 5 0.29 Phenol 0.061 32 3.7 5 0.29 2,2′ Bisphenol 0.0602 16 3.8 5 0.29 Bisphenol F 0.0646 16

(41) TABLE-US-00017 TABLE 3.0 Without phenolic compound t [min] Mn Mw PDI M.sub.W.sup.n 0 78.818 267.888 3.4 1 30 78.607 247.155 3.4 0.92 60 73.686 227.829 3.1 0.85 120 69.850 201.274 2.9 0.75

(42) TABLE-US-00018 TABLE 3.1 Vulkanox ® BKF t [min] Mn Mw PDI M.sub.W.sup.n 0 78.818 267.888 3.4 1 30 71.530 244.566 3.4 0.91 60 69.991 225.212 3.2 0.84 120 61.406 191.359 3.1 0.71 240 56.057 159.784 2.9 0.60

(43) TABLE-US-00019 TABLE 3.2 Vulkanox ® BHT t [min] Mn Mw PDI M.sub.W.sup.n 0 78.818 267.888 3.4 1 30 73.382 244.437 3.3 0.91 60 72.518 232.662 3.2 0.87 120 62.455 191.222 3.1 0.71 240 58.324 159.205 2.7 0.59

(44) TABLE-US-00020 TABLE 3.3 Irganox ® 1076 t [min] Mn Mw PDI M.sub.W.sup.n 0 78.818 267.888 3.4 1 30 76.617 246.289 3.2 0.92 60 72.299 226.869 3.1 0.85 120 68.890 199.815 2.9 0.75 240 64.542 171.813 2.7 0.64

(45) TABLE-US-00021 TABLE 3.4 Irganox ® 1520 t [min] Mn Mw PDI M.sub.W.sup.n 0 78.818 267.888 3.4 1 30 77.703 244.076 3.1 0.91 60 74.625 226.538 3.1 0.85 120 70.874 201.090 2.9 0.75 240 64.878 177.213 2.7 0.66 240 64.985 175.507 2.7 0.66

(46) TABLE-US-00022 TABLE 3.5 Naugawhite ® t [min] Mn Mw PDI M.sub.W.sup.n 0 78.818 267.888 3.4 1 30 72.459 245.433 3.4 0.92 60 72.238 224.834 3.1 0.84 120 62.679 187.436 3 0.70 240 55.243 151.250 2.7 0.56

(47) TABLE-US-00023 TABLE 3.6 Phenol t [min] Mn Mw PDI Mw.sup.n 0 90.524 336.434 3.7 1 30 85.358 274.194 3.2 0.82 60 85.757 270.488 3.2 0.80 120 83.796 263.796 3.1 0.78 240 82.463 260.463 3.2 0.77

(48) TABLE-US-00024 TABLE 3.7 2,2-Bisphenol t [min] Mn Mw PDI Mw.sup.n 0 90.524 336.434 3.7 1 30 86.726 287.247 3.3 0.85 60 86.414 280.528 3.2 0.83 120 83.430 269.865 3.2 0.80 240 82.623 261.362 3.2 0.78

(49) TABLE-US-00025 TABLE 3.8 Bisphenol F t [min] Mn Mw PDI Mw.sup.n 0 90.524 336.434 3.7 1 30 87.143 290.594 3.3 0.86 60 87.831 286.988 3.3 0.85 120 85.923 281.070 3.3 0.84 240 87.143 279.175 3.2 0.83

(50) Metathesis of NBR with Different Metathesis Catalysts and Addition of Naugawhite®

(51) In a 250 mL Schlenk flask fitted with a reflux cooler and a magnetic stirrer 5 g of the NBR purified according to protocol 2 and dried were dissolved in 45 g of MCB and admixed with 0.155 phr of Naugawhite®. The thus-obtained solution was degassed and inertized with argon. 8 Phr of 1-dodecene and the relevant amount of the fresh catalyst solution were added countercurrently. The different catalysts and the employed amounts thereof are shown in table 4 below. The reaction mixture was stirred for 4 hours. Respective 2 mL samples were removed after reaction times of 30, 60, 120 and 240 minutes and, in a screw top vial, reacted with 0.5 mL of ethyl ether to terminate the metathesis reaction. The samples were analyzed by GPC.

(52) TABLE-US-00026 TABLE 4 Metathesis of NBR with different metathesis catalysts and identical amount of phenolic compound (Naugawhite ®) NBR Metathesis catalyst Naugawhite ® No. [g] [phr] [μmol] [phr] [μmol] 4.1 5 Grubbs II 0.0052 29 0.155 16 4.2 5 Grubbs III 0.0052 29 0.155 16 4.3 5 Grubbs-Hoveyda II 0.0037 29 0.155 16 4.4 5 Grela 0.0039 29 0.155 16 4.5 5 Fluorenylidene K2 0.0053 29 0.155 16

(53) TABLE-US-00027 TABLE 4.1 Grubbs II t [min] Mn Mw PDI M.sub.W.sup.n 0 82.309 300.137 3.6 1 30 77.355 271.178 3.5 0.90 60 69.650 230.549 3.3 0.77 120 60.680 172.187 2.8 0.57 240 43.337 111.555 2.6 0.37

(54) TABLE-US-00028 TABLE 4.2 Grubbs III t [min] Mn Mw PDI M.sub.W.sup.n 0 82.309 300.137 3.6 1 30 64.954 204.445 3.1 0.68 60 56.704 166.005 2.9 0.55 120 53.082 141.737 2.7 0.47 240 48.281 128.343 2.7 0.43

(55) TABLE-US-00029 TABLE 4.3 7.2 Grubbs-Hoveyda II t [min] Mn Mw PDI M.sub.W.sup.n 0 82.309 300.137 3.6 1 30 48.812 126.433 2.6 0.42 60 35.568 86.390 2.4 0.29 120 29.933 70.143 2.3 0.23 240 26.301 61.285 2.3 0.20

(56) TABLE-US-00030 TABLE 4.4 Grela catalyst t [min] Mn Mw PDI M.sub.W.sup.n 0 82.309 300.137 3.6 1 30 41.123 91.334 2.2 0.30 60 33.990 71.893 2.1 0.24 120 31.449 65.135 2.1 0.22 240 29.823 61.087 2 0.20

(57) TABLE-US-00031 TABLE 4.5 Fluorenylidene K2 t [min] Mn Mw PDI M.sub.W.sup.n 0 90.907 303.323 3.3 1 30 57.990 146.410 2.5 0.48 60 44.057 98.707 2.2 0.33 120 35.083 74.144 2.1 0.24 240 30.509 62.826 2.1 0.21

(58) The tested metathesis catalysts Grubbs II, Grubbs III, Grubbs-Hoveyda II, Grela and Fluorenylidene K2 show metathesis activity in the presence of 0.155 phr of phenolic compound (Naugawhite®). The metathesis catalysts Grubbs-Hoveyda II, Grela and Fluorenylidene K2 exhibit the strongest degradation of molecular weight in the shortest time.