CATALYSTS FOR PREPARATION OF ULTRA HIGH MOLECULAR WEIGHT POLYETHYLENE (UHMWPE) AND PROCESS FOR PREPARATION THEREOF

Abstract

The present invention relates to novel polymerization catalysts. More particularly, the present invention relates to a novel catalysts for the preparation of ultra high molecular weight polyethylene (UHMWPE) and process for preparation thereof. The present invention further relates to a process for the preparation of disentangled ultra high molecular weight polyethylene (dis-UHMWPE).

##STR00001##

Claims

1. A novel olefin polymerization catalyst comprising metal complexes of Formula (I). ##STR00014## Wherein M is a transition metal atom of Group 3 to Group 11 of the periodic table; B is sulfonate (SO.sub.3) or carboxylate (CO.sub.2); When n=0, D=NCH or when n=1, D=N; X=Cl, Br, I, BF.sub.4, OAc; R, R.sub.1 to R.sub.4 are selected from the same or different, and are each a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residue, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group, and two or more of them may be bonded to each other to form a ring, R.sub.1 is any aromatic compound, or mono, di, tri, tetra, penta substituted phenyl compound, one or more or all five substituent selected from F, Cl, Br, I.

2. The novel olefin polymerization catalyst as claimed in claim 1, wherein said transition metals are selected from titanium, zirconium, hafnium, vanadium, ytterbium and niobium.

3. The novel olefin polymerization catalyst as claimed in claim 1, wherein said compound of Formula (I) is selected from Bis[2-(((2,3,4,5,6-pentaflourophenyl)imino)methyl)benzenesulfonato]titanium(IV) Dichloride or Bis[2-(((4-methoxybenzylidene)amino)benzoate]Ti(IV) Dichloride.

4. A process for the preparation of catalyst of Formula (I) as claimed in claim 1 comprising the steps of: a) stirring the reaction mixture of sodium salt of aldehyde and amine in suitable solvent in presence of alkyl/aryl sulfonic acid followed by refluxing the reaction mixture at temperature ranging from 140 to 160 C. for the period ranging from 4 h to 6 h to obtain imine compound; b) adding organic solvent solution of metal halide to a stirred solution of compound of step (a) in suitable solvent at the temperature ranging from 78 C. to 80 C. followed by stirring the reaction mixture for the time period ranging from 18 to 20 h at the temperature ranging from 25 C. to 40 C. to obtain compound of Formula (I) wherein B is sulfonate group.

5. The process as claimed in claim 4, wherein said sodium salt of aldehyde is selected from 2-formylbenzenesulfonic acid, sodium 2-formyl-6-methylbenzenesulfonate, sodium 2-(tert-butyl)-6-formylbenzenesulfonate.

6. The process as claimed in claim 4, wherein said amine is aliphatic or aromatic; said amine is aromatic amine; said amine is selected from 2,3,4,5,6-pentafluoroaniline, 2,6-difluoroaldehyde, anisaldehyde, benzaldehyde.

7. The process as claimed in claim 4, wherein said solvent of step (a) is selected from dimethyl formamide, dimethyl sulfoxide, methanol, acetonitrile, benzonitrile.

8. The process as claimed in claim 4, wherein said alkyl sulfonic acid is selected from p-toluenesulfonic acid, methane sulfonic acid, trifluromethane sulfonic acid, acetic acid.

9. The process as claimed in claim 4, wherein said organic solvent of step (b) is selected from toluene, heptane, decane, xylene.

10. The process as claimed in claim 4, wherein said metal halide is selected from titanium tetrachloride, zirconium tetrachloride, titanium tetrabromide, zirconium tetrabromide.

11. The process as claimed in claim 4, wherein said solvent of step (b) is selected from dimethyl formamide, dimethyl sulfoxide, toluene, diethyl ether, dioxane.

12. A process for the preparation of catalyst of Formula (I) as claimed in claim 1 comprising the steps of: a) stirring the reaction mixture of aldehyde and amine in suitable solvent in presence of alkylsulfonic acid followed by refluxing the reaction mixture at temperature ranging from 65 to 70 C. for the period ranging from 4 h to 6 h to obtain amino compound; b) adding alkyllithium/n-hexane solution to a stirred solution of step (a) in solvent at the temperature ranging from 78 C. to 80 C. followed by stirring the reaction mixture for the time period ranging from 3 to 4 h at the temperature ranging from 25 C. to 40 C.; c) adding solution of metal halide in organic solvent to a solution of step (b) at the temperature ranging from 78 C. to 80 C. followed by stirring the reaction mixture for the time period ranging from 18 to 20 h at the temperature ranging from 25 C. to 40 C. to obtain compound of Formula (I) wherein B is carboxylate group.

13. The process as claimed in claim 12, wherein said amine is selected from 2-amino-6-methylbenzoic acid, antranilic acid, 2-amino-6-tert-butylbenzoic acid.

14. The process as claimed in claim 12, wherein said aldehyde is selected from 2,3,4,5,6-pentafluoroaldehyde, 2,6-difluoroaldehyde, anisaldehyde, benzaldehyde.

15. The process as claimed in claim 12, wherein said solvent of step (a) is polar solvent; said solvent is alcohol; said alcohol is selected from methanol, ethanol, propanol.

16. The process as claimed in claim 12, wherein said solvent of step (b) is tetrahydrofuran, toluene, diethyl ether, dioxane.

17. The process as claimed in claim 12, said organic solvent is selected from toluene, xylene, hexane, heptane.

18. The process as claimed in claim 12, said metal halide is selected from titanium tetrachloride, zirconium tetrachloride, titanium tetrabromide, zirconium tetrabromide.

19. A process for the preparation of disentangled ultra high molecular weight polyethylene using said polymerization catalysts of Formula (I) as claimed in claim 1 in the presence of a co-catalyst comprising the steps of: a) mixing the co-catalyst in a solvent followed by pressurizing the ethylene gas in reaction vessel; b) polymerizing ethylene by addition of the polymerization catalysts of Formula (I) dissolved in solvent at the temperature ranging from 0 to 45 C.

20. The process as claimed in claim 19, wherein said co-catalyst is selected from methylaluminoxane (MAO) and trialkylaluminium.

21. The process as claimed in claim 19, wherein said solvent of step (b) is hydrocarbon; said solvent is saturated or unsaturated hydrocarbon; said solvent is selected from toluene, xylene, heptane, decane.

22. The process as claimed in claim 19, wherein said polymerisation temperature for preparation of disentangled ultra high molecular weight polyethylene is ranging from 0 to 45 C.; said temperature ranging from 35 to 40 C.

23. The process as claimed in claim 19, wherein said polymerization reaction is carried out in continuous or batch mode.

24. The process as claimed in claim 19, wherein said polymerization is carried out under a pressure of 1 to 10 bars.

25. The process as claimed in claim 19, wherein the concentration of said catalyst is in the range of 1 to 10 mol.

26. The process as claimed in claim 19, wherein said co-catalyst system comprise scavenger; said scavenger is selected from triethylaluminium, triisobutylaluminum, tris-n-octylaluminium, tetraisobutyl-dialuminoxane, diethyl zinc, tris-n-hexyl aluminum or diethylchloro aluminum.

27. The process as claimed in claim 19, wherein the average molecular weight of said disentangled ultra high molecular weight polyethylene is ranging from 1 to 10 million g/mol.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0036] FIG. 1: DSC heating and cooling curves for the polyethylene P1.

[0037] FIG. 2: DSC heating and cooling curves for the polyethylene P2.

[0038] FIG. 3: .sup.1H NMR of polyethylene P1 measured at 130 C in TCB-C.sub.6D.sub.6 mixture.

DETAILED DESCRIPTION OF THE INVENTION

[0039] The invention will now be described in detail in connection with certain preferred and optional embodiments, so that various aspects thereof may be more fully understood and appreciated.

[0040] The present invention provides a novel olefin polymerization catalyst comprising metal complexes of formula (I) containing iminesulfonate ligands or iminecarboxylate ligands.

##STR00007##

[0041] Wherein

[0042] M is a transition metal atom of Group 3 to Group 11 of the periodic table, said transition metal is titanium;

[0043] B is sulfonate (SO.sub.3) or carboxylate (CO.sub.2),

[0044] When n=0, D=NCH.sub.; OR when n=1, D=N,

[0045] X=halogen, Cl, Br, I, BF.sub.4, OAc;

[0046] R, R.sub.1 to R.sub.4 may be the same or different, and are each a hydrogen atom, a halogen atom, a hydrocarbon group, a heterocyclic compound residue, an oxygen-containing group, a nitrogen-containing group, a boron-containing group, a sulfur-containing group, a phosphorus-containing group, a silicon-containing group, a germanium-containing group or a tin-containing group, and two or more of them may be bonded to each other to form a ring, R.sub.1 may be any aromatic compound, or mono, di, tri, tetra, penta substituted phenyl compound, one or more or all five substituent could be F, Cl, Br, I.

[0047] In preferred embodiment, said transition metals are selected from titanium, zirconium, hafnium, vanadium, ytterbium and niobium.

[0048] In another preferred embodiment, said compound of Formula (I) is selected from Bis[2-(((2,3,4,5,6-pentaflourophenyl)imino)methyl)benzenesulfonato]titanium(IV) Dichloride or Bis[2-(((4-methoxybenzylidene)amino)benzoate]Ti(IV) Dichloride. In an embodiment, the present invention provides a process for the preparation of catalyst of Formula (I) comprising the steps of: [0049] a) stirring the reaction mixture of sodium salt of aldehyde and amine in suitable solvent in presence of alkyl/aryl sulfonic/carboxylic acid followed by refluxing the reaction mixture at temperature ranging from 140 to 160 C. for the period ranging from 4 h to 6 h to obtain imine compound; [0050] b) adding organic solvent solution of metal halide to a stirred solution of compound of step (a) in suitable solvent at the temperature ranging from 78 C. to 80 C. followed by stirring the reaction mixture for the time period ranging from 18 to 20 h at the temperature ranging from 25 C. to 40 C. to obtain compound of Formula (I) wherein B is sulfonate group.

[0051] In preferred embodiment, said sodium salt of aldehyde is selected from 2-formylbenzenesulfonic acid, sodium 2-formyl-6-methylbenzenesulfonate, sodium 2-(tert-butyl)-6-formylbenzenesulfonate.

[0052] In another preferred embodiment, said amine is aliphatic or aromatic; preferably said amine is aromatic amine; more preferably said amine is selected from 2,3,4,5,6-pentafluoroaniline, 2,6-difluoroaldehyde, anisaldehyde, benzaldehyde.

[0053] In still another preferred embodiment, said solvent of step (a) is selected from dimethyl formamide, dimethyl sulfoxide, methanol, acetonitrile, benzonitrile.

[0054] In yet another preferred embodiment, said alkyl sulfonic acid is selected from p-toluenesulfonic acid, methane sulfonic acid, acetic acid, trifluromethane sulfonic acid.

[0055] In yet another preferred embodiment, said organic solvent of step (b) is selected from toluene, xylene, hexane, heptane.

[0056] In still yet another preferred embodiment, said metal tetrahalide is selected from titanium tetrachloride, zirconium tetrachloride, titanium tetrabromide, zirconium tetrabromide.

[0057] In still yet another preferred embodiment, said solvent of step (b) is selected from dimethyl formamide, dimethyl sulfoxide, toluene, diethyl ether, dioxane.

[0058] In another embodiment, the present invention provides a process for the preparation of catalyst of Formula (I) comprising the steps of: [0059] a) stirring the reaction mixture of aldehyde and amine in suitable solvent in presence of alkyl/aryl sulfonic/carboxylic acid followed by refluxing the reaction mixture at temperature ranging from 150-160 C./65 to 70 C. for the period ranging from 4 h to 6 h to obtain amino compound; [0060] b) adding alkyllithium/n-hexane or sodium hydride/THF solution to a stirred solution of step (a) in solvent at the temperature ranging from 78 C. to 80 C. followed by stirring the reaction mixture for the time period ranging from 3 to 4 h at the temperature ranging from 25 C. to 40 C.; [0061] c) adding solution of metal halide in organic solvent to a solution of step (b) at the temperature ranging from 78 C. to 80 C. followed by stirring the reaction mixture for the time period ranging from 18 to 20 h at the temperature ranging from 25 C. to 40 C. to obtain compound of Formula (I) wherein B is sulfonate or carboxylate group.

[0062] In preferred embodiment, said amine is selected from 2-amino-6-methylbenzoic acid, antranilic acid, 2-amino-6-tert-butylbenzoic acid.

[0063] In another preferred embodiment, said aldehyde is selected from 2,3,4,5,6-pentafluoroaldehyde, 2,6-difluoroaldehyde, anisaldehyde, benzaldehyde.

[0064] In still another preferred embodiment, said solvent of step (a) is polar solvent; said solvent is alcohol; said alcohol is selected from methanol, ethanol, propanol.

[0065] In yet another preferred embodiment, said solvent of step (b) is tetrahydrofuran, toluene, diethyl ether, dioxane.

[0066] In still yet another preferred embodiment, said organic solvent is selected from toluene, xylene, hexane, heptane.

[0067] In still yet another preferred embodiment, said metal-halide is selected from titanium tetrachloride, zirconium tetrachloride, titanium tetrabromide, zirconium tetrabromide.

[0068] The presence of an acidic group in the compounds of Formula (I) increases the electron density on the metal centre due to extensive conjugation and makes them comparatively more stable. The appropriate combination of heteroatom and an acidic group can regulate the electron density at the metal centre in such a way that it reduces formation of undesirable multi-site catalyst under defined conditions.

[0069] In still another embodiment, the present invention provides a process for olefin polymerizations using polymerization catalysts of Formula (I) in the presence of a co-catalyst.

[0070] In preferred embodiment, the present invention provides a process for the preparation of disentangled ultra high molecular weight polyethylene using said polymerization catalysts of Formula (I) in the presence of a co-catalyst comprising the steps of: [0071] a) Mixing the co-catalyst in a solvent followed by pressurizing the ethylene gas in reaction vessel; [0072] b) Polymerizing ethylene by addition of the polymerization catalysts of formula (I) dissolved in solvent at the temperature ranging from 0 to 45 C.

[0073] In another preferred embodiment, said co-catalyst is selected from methylaluminoxane (MAO) and trialkylaluminium.

[0074] In still another preferred embodiment, said solvent of step (b) is hydrocarbon; preferably said solvent is saturated or unsaturated hydrocarbon; preferably said solvent is selected from toluene, xylene, heptane, decane, dodecane.

[0075] In yet another preferred embodiment, said polymerisation temperature for preparation of disentangled ultra high molecular weight polyethylene is ranging from 0 to 45 C.; preferably said temperature ranging from 35 to 40 C.

[0076] In still yet another preferred embodiment, said polymerization reaction is carried out in continuous or batch mode.

[0077] In still yet another preferred embodiment, said polymerization is carried out under a pressure of about 1 to 10 bars.

[0078] In still yet another preferred embodiment, the concentration of said catalyst is in the range of 1 to 10 mol.

[0079] In still yet another preferred embodiment, said co-catalyst system may comprise an optional scavenger that may be selected from triethylaluminium, triisobutylaluminum, tris-n-octylaluminium, tetraisobutyl-dialuminoxane, diethyl zinc, tris-n-hexyl aluminum or diethylchloro aluminum.

[0080] In still yet another preferred embodiment, the average molecular weight of said disentangled ultra high molecular weight polyethylene is in the range of 1 to 10 million g/mol.

[0081] The disclosed neutral nickel complexes in the U.S. Pat. No. 6,174,976 form five membered (using bidentate ligand) constrained ring as shown in the following structure (which has been claimed in the above US patent). Such five membered rings are highly strained and unstable, leading to undefined catalytic species. In contrast, inventor catalysts are capable of forming six, seven membered ring and thus provide enhanced stability. Therefore, the claimed metal catalyst in above US patent is a very different system and cannot be compared with six and seven membered systems.

[0082] Synthesis of imine is known in the art and there are ample reports. However, synthesis of imine, in presence of an acid (carboxylic or sulfonic) for the said ligand is not reported.

[0083] PCT Appl. No. 2013020896 claims the synthesis of iminonaphthol ligands and their metal complexes. The patent deals with the synthesis of naphthoxy-imine ligands and their metal complexes. However, it does not report, even remotely any sulfonate or carboxylate system. Therefore, this document is limited to naphthoxy-imine ligands and corresponding metal complexes only. Inventor patent application is beyond the claims of this patent.

[0084] The following examples, which include preferred embodiments, will serve to illustrate the practice of this invention, it being understood that the particulars shown are by way of example and for purpose of illustrative discussion of preferred embodiments of the invention.

Examples

Example 1 (a): Synthesis of 2-(((2,3,4,5,6-pentaflourophenyl)imino)methyl) benzenesulfonic acid (L1)

[0085] ##STR00008##

[0086] To a stirred mixture of sodium salt of 2-formylbenzenesulfonic acid (10.4 gm, 50 mmol) and 2,3,4,5,6-pentafluoroaniline (10.9 gm, 50 mmol) in dry DMF (500 mL) was added in presence of p-toluenesulfonic acid (200 mg) at room temperature. The resulting mixture was stirred at 155-160 C. reflux temperature for 4 h and concentration of the reaction mixture in vacuo afforded a crude solid. Purification by column chromatography on silica gel using Ethylacetate/Methanol (9/1) as eluent gave sodium 2-(((perfluorophenyl) imino) methyl)benzenesulfonate as white solid in 32% yield.

[0087] .sup.1H NMR (CD.sub.3OD) 9.68 (s, 1H, CH of imine), 8.35 (d, 1H, ArH), 8.07 (d, 1H, ArH), 7.63 (m, 2H, ArH), 7.8 (m, 1H, aromatic-H), 7.23-7.26 (m, 1H, aromatic-H), 7.47 (dd, J.sub.H-H=7.7, 1.5 Hz, 1H, aromatic-H), 8.81 (s, 1H, CHdN), 12.88 (s, 1H, COOH). .sup.13C NMR (CD.sub.3OD) 168, 146, 140, 138, 137, 132, 131, 130, 128, 127, 125.

Example 1 (b): Synthesis of Bis[2-(((2,3,4,5,6-pentaflourophenyl)imino)methyl) benzenesulfonato]titanium(IV) Dichloride (M1)

[0088] ##STR00009##

[0089] To a stirred solution of sodium 2-(((perfluorophenyl)imino)methyl)benzenesulfonate L1(4.24 g, 5 mmol) in dried dimethyl formamide (15 mL) was added 1M toluene solution of TiCl.sub.4 (2.5 mL, 5.00 mmol) dropwise over a 10-min period at 78 C. The reaction temperature was maintained for 30 min. with constant stirring. The mixture was allowed to warm to room temperature and stirred for 18 h. Concentration of the reaction mixture in vacuo gave a crude product. Dried CH.sub.2Cl.sub.2 (50 mL) was added to the crude product, and the mixture was stirred for 15 min. and then filtered. The solid residue was washed two times with dried hexane (30 mL each), and the combined organic filtrates were concentrated in vacuo to afford a reddish brown solid.

[0090] .sup.1H NMR (CDCl.sub.3) =9.47 (s, 2H, imine-CH), 8.30 (s, 2H, ArH), 8.11 (s, 2H, ArH), 7.52 (s, 4H, ArH).

Example 2: Ethylene Polymerization using Bis[2-(((2,3,4,5,6-pentaflourophenyl) imino)methyl)benzenesulfonato]titanium(IV) Dichloride (M1) as a catalyst

[0091] A dried Buchi reactor equipped with overhead stirrer, thermometer probe was heated at 80 C. temperature under vacuum for 60 min. Under this temperature the reactor was pressurized with argon gas for 40 minutes. Dried toluene is introduced to the reaction flask, followed by addition of 20% MAO out of required amount, and argon is bubbled through the solvent for 40 min under stirring. The argon is then replaced by ethylene gas, which is left bubbling through the solvent. After 30 min, the 70% amount of MAO is introduced, and the reaction flask is then placed at the desired temperature. When the requisite temperature is reached, the polymerization is initiated by addition of the precatalyst {Bis[2-(((2,3,4,5,6-pentaflourophenyl) imino)methyl) benzenesulfonato]titanium(IV) Dichloride} previously dissolved in 2 mL of dry dimethyl formamide/dimethyl sulfoxide and activated by remaining 10% of MAO solution. After the required polymerization time, the polymerization is quenched by addition of an acidified MeOH solution. The resulting polyethylene is filtered, washed with copious amounts of methanol/acetone, and dried overnight in a vacuum oven at 40 C. Polymer yield: 0.096 mg. Catalyst activity: 960 kg-polymer/mmol Ti/h. Melting temperature (Tm): 134.36 C.

##STR00010##

Example 3 (a): Synthesis of 2-(((4-methoxybenzylidene)amino)benzoic acid (L2)

[0092] ##STR00011##

[0093] To a stirred mixture of 2-aminobenzoic acid (6.8 gm, 50 mmol) and 4-methoxybenzaldehyde (6.1 gm, 50 mmol) in ethanol (500 mL) was added p-toluenesulfonic acid (300 mg) at room temperature. The resulting mixture was stirred at temperature 78 C. for 6 h and concentrated in vacuo that afforded a crude reaction mixture. Purification by column chromatography on silica gel using ethyl acetate/pet-ether (9/1) as eluent gave 2-(((4-methoxybenzylidene)amino)benzoic acid (L2) as off white solid in 92% yield.

[0094] .sup.1H NMR (CDCl.sub.3) =14.98 (s, br, ArCOOH), 8.64 (s, 1H, imine CH), 8.34 (d, 1H, ArH), 7.88 (d, 2H, ArH), 7.60 (t, 1H, ArH), 7.46 (m, 2H, ArH), 7.05 (d, 2H, ArH), 3.90 (s, 3H, OCH3). .sup.13C NMR (CDCl.sub.3) =190.6, 167.2, 163.8, 159.6, 150.8, 146.9, 134.5, 133.6, 132.5, 131.7, 127.4, 126.2, 123.7, 116.4, 114.6, 114.0, 55.3.

Example 3 (b): Synthesis of Bis[2-(((4-methoxybenzylidene)amino)benzoate]Ti(IV) Dichloride (M2)

[0095] ##STR00012##

[0096] To a stirred solution of 2-(((4-methoxybenzylidene)amino)benzoic acid (L2) (1.38 g, 5 mmol) in dried solvent mixture of dichloromethane (50 mL), THF (20 mL) comprising NaH (0.122 g, 5.25 mmol) was added dropwise over the period of 10 min at room temperature under argon. The reaction mixture was stirred for 4 h. The resulting solution was added dropwise over a 10-min period to a 1M toluene solution of TiCl.sub.4 (2.5 mL, 2.5 mmol) in dried THF (50 mL) at 78 C. to 0 C. The mixture was allowed to warm to room temperature and stirred for 18 h. Concentration of the reaction mixture in vacuo gave a crude product. Dried hexane (50 mL) was added to the crude product, and the mixture was stirred for 15 min and then filtered. Diethyl ether (30 mL) and n-hexane (120 mL) were added to the solid, and the mixture was stirred for 60 min and then filtered. The resulting solid was washed with n-hexane (20 mL) and dried in vacuo to give required complex M2 as a reddish brown solid in 42% yield.

[0097] .sup.1H NMR (CD.sub.2Cl.sub.2) =8.69 (s, 2H, imine CH), 8.30 (d, 1H, ArH), 7.93 (m, 4H, ArH), 7.68 (m, 1H, ArH), 7.52 (m, 4H, ArH), 7.10 (m, 4H, ArH), 6.72 (m, 2H, ArH), 3.91 (d, 6H, OCH.sub.3).

Example 4: Ethylene Polymerization using Bis[2-(((4-methoxybenzylidene)amino)benzoate]Ti(IV) Dichloride (M2) as a catalyst

[0098] A dried Buchi reactor equipped with a overhead stirrer, thermometer probe was heated at 80 C. temperature under vacuum for 60 min. Under this temperature the reactor was pressurised with argon gas for 40 minutes. Dried toluene is introduced to the reaction flask, followed by addition of 20% MAO out of required amount, and argon is bubbled through the solvent for 40 min under stirring. The argon is then replaced by ethylene gas, which is left bubbling through the solvent. After 30 min, the 70% amount of MAO is introduced, and the reaction flask is then placed at the desired temperature. When the requisite temperature is reached, the polymerization is initiated by addition of the precatalyst {Bis[2-(((4-methoxybenzylidene)amino)benzoate]Ti(IV) Dichloride (M2)} previously dissolved in 2 mL of dry dimethyl formamide/dimethyl sulfoxide and activated by remaining 10% of MAO solution. After the required polymerization time, the polymerization is quenched by addition of an acidified MeOH solution. The resulting polyethylene is filtered, washed with copious amounts of methanol/acetone, and dried overnight in a vacuum oven at 40 C. Polymer yield: 0.156 mg. Catalyst activity: 1560 kg-polymer/mmole Ti/h. Tm: 137.29 C.

##STR00013##

Advantages of Invention

[0099] 1. Simple Iminecarboxylate or Iminesulfonate ligated metal complexes are used in the preparation of disentangle ultra high molecular weight polyethylene. [0100] 2. The Disentangle ultra high molecular weight polyethylene (dis-UHMWPE) prepared by using the catalyst of present invention has improved physical and mechanical properties such as chemical inertness, lubricity, impact resistance, and abrasion resistance. [0101] 3. The dis-UHMWPE prepared may find various applications such as bullet proof jackets, helmets, total joint replacement, spine implant, hip replacement, blood filters and high strength light weighted strong fibers and tapes. [0102] 4. The presence of acidic group in ligand framework will enhance the catalyst stability under given reaction conditions.