Abstract:
Methods and compositions for the generation of quasi-living catalysts for homo-polymerization of olefins such as ethylene, α-olefins and functionalized olefins and for the co-polymerization of olefins with functionalized monomers is disclosed. A process for producing these homo- and co-polymers is also disclosed. A polymeric material with enhanced hydrophilic properties, generated by the co-polymerization of ethylene with 5-norbornen-2-yl acetate, is also disclosed.

Description:
BACKGROUND OF THE INVENTION 
     Description of the Related Art 
     Catalysts for olefin co-polymerization with functional monomers are rare compared to their olefin polymerization counterparts (See reference 1). PCT patent application WO01/92348 describes the co-polymerization of ethylene using zwitterionic nickel complexes requiring Lewis acids. Lewis Acids are deactivated by functionalities and they promote unwanted secondary reactions, e.g., chain transfer, which are detrimental to the polymer chain growth. Other types of neutral catalysts, capable of homo-and co-polymerizing olefins, have been reported by Younkin et al. (See reference 2). The catalysts are neutral species that do not require an activator, however, they are prone to an induction period and have lower activity compared to cationic systems which perform in the presence of methylaluminoxanes and Lewis acids. 
     Furthermore, co-polymerization catalysts displaying characteristics of living polymerizations, are even rarer (See reference 3). The ideal catalyst-system would produce a living or quasi-living polymer. There are seven accepted criteria for living polymerizations with living catalyst systems. These are: 1) The polymerization proceeds to a complete monomer conversion and restarts upon further addition of the monomer; 2) Linear dependence of Mn with time; 3) The number of active sites remains constant during polymerization; 4) The molecular weight can be precisely controlled by stoichiometry; 5) A narrow PDI; 6) Sequential monomer addition results in a block co-polymer; and 7) An end-functionalized co-polymer can be synthesized. Systems that partially fulfill this list of criteria are termed “quasi-living”. Jansen et. al., reported quasi-living catalysts for ethylene and norbornene co-polymerization (See reference 4). However, no functionalized norbornene derivatives were co-polymerized. 
     SUMMARY OF THE INVENTION 
     The present invention provides a method of using a novel quasi-living metal catalyst for homo-polymerization of olefins such as ethylene, α-olefins and functionalized olefins and for co-polymerization of olefins with functionalities such as acetates (e.g., 5-norbornen-2-yl acetate). Specifically, the catalyst comprises a combination of two neutral metal complexes, e.g., L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) [L=N-(2,6-diisopropylphenyl)-2-(2,6-diisopropylphenylimino)propanamide] (See reference 5) and Ni(COD) 2  (COD=cyclooctadiene) that produces high molecular weight polymers, found experimentally to be about (M n ) 2.20×10 4  to about 1.10×10 5  for ethylene homo-polymers and about (M n ) 3.90×10 4  to about 1.10×10 5  for acetate-functionalized co-polymers with narrow molecular weight distributions, in the range of about 1.3-1.6 for ethylene homo-polymers and about 1.2-1.6 for acetate-functionalized co-polymers, respectively. 
     In one embodiment, the present invention discloses a process comprising combining an amount of a first olefin monomer with an initiator metal compound so that a polymer chain is generated. The initiator metal compound comprises a Group VIII transition metal complex, the complex comprising a combination of any two neutral metal complexes of the general formulas (I-IV) 
     
       
                 
         
             
             
         
      
     
     wherein: 
     M is a Group VIII transition metal such as Ni, Pt, or Pd; 
     A is a three electron donor such as π-allyl, substituted π-allyl, π-benzyl, or substituted π-benzyl; 
     X is N or P; 
     Y is O, CH 2 , or S; 
     L is N or P or a structure that is capable of forming a neutral two electron donor ligand; 
     L 2  is a neutral monodentate ligand; 
     L 1  is a neutral monodentate ligand which may be displaced by the olefin, and L 2  is an monoanionic monodentate ligand, or L 1  and L 2  taken together are a monoanionic bidentate ligand, provided that the monoanionic monodentate ligand or the monoanionic bidentate ligand may add to the olefin; 
     B is an atom or group of atoms connecting covalently the carbonyl group and L; 
     R 1  each independently is hydrogen, hydrocarbyl, substituted hydrocarbyl bearing functional group, or other hydrocarbyl group; 
     R 2  each independently is hydrogen, hydrocarbyl, substituted hydrocarbyl bearing functional group, or other hydrocarbyl group; and 
     R 3  each independently is hydrogen, hydrocarbyl, substituted hydrocarbyl bearing functional group, or other hydrocarbyl group; and combining an amount of a second olefin monomer with the polymer chain so that the second olefin monomer is added to the polymer chain. The process of the present invention includes continuous olefin monomer feeds to the metal compound. 
     In another embodiment of the present invention, the amount of the first and/or second olefin monomers is depleted, after the polymer chain is generated. 
     In yet another embodiment of the invention the transition metal of the metal catalyst is nickel. 
     In a further embodiment of the invention, the first and second olefin monomers are the same or different and are 5-norbornen-2-yl acetate or ethylene. 
     In a further embodiment of the present invention, R 1 =R 3 =(2,6-diisopropylphenyl); R 2 =methyl; X=L=Nitrogen; Y=Oxygen; B=carbon; L 1 =CH 2 Ph; and L 2 =PMe 3 . 
     In another embodiment, the present invention discloses a process for the quasi-living homo-polymerization and quasi-living co-polymerization of an olefin wherein the olefin is selected from one or more of R 4 CH═CH 2 , cyclopentene, a styrene, a norbornene, or a polar olefin of the general formula H 2 C═CR 5 (CH 2 ) S CO 2 R 6 , substituted cyclopentene, substituted styrene, norbornene derivative bearing functional group or other hydrocarbyl group, in the presence of a catalyst derived from a combination of two neutral transition metal complexes, at a temperature of about −100° C. to about 200° C. R 4 , R 5  and R 6  are each independently hydrogen, hydrocarbyl group, substituted hydrocarbyl bearing functional group, or other hydrocarbyl group and s is an integer from 0 to 100. 
     In yet a further embodiment of the invention, products prepared by the above-described processes are disclosed. These polymer products are characterized by having a narrow molecular weight distribution of about 1.2-1.6. 
     In still a further embodiment of the present invention, a polymer product prepared by the above-described processes is a block co-polymer, a star-shaped polymer, a graft polymer or an alternating polymer. 
     In still yet a further embodiment of the present invention, a polymer is made by the quasi-living co-polymerization of ethylene with 5-norbornen-2-yl acetate. The polymer has enhanced hydrophilic properties. 
     The quasi-living characteristics of the catalyst facilitates the generation of a novel polymeric product, such as functionalized block co-polymers that are of substantial industrial interest. The present invention displays quasi-living characteristics for ethylene homo-polymerization and also for co-polymerization with a functionalized polar monomer, thereby underscoring the versatility of the catalyst. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a graphical representation of an embodiment of the present invention showing the number average molecular weight (M n ) versus time of the samples in Table 1 and described in Examples 2, 3, 4 and 5; 
         FIG. 2  is a Gel Permeation Chromatography (GPC) trace of the polyethylene obtained in Examples 4 and 5; and 
         FIG. 3  is a graphical representation of an embodiment of the present invention showing M n  versus time for the co-polymerization of ethylene with 5-norbornen-2-yl acetate described in Examples 7, 8, 9 and 10 and shown in Table 3. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The following examples were performed under an inert atmosphere using standard glove box and Schlenk techniques. Solvents like toluene, tetrahydrofuran (THF), hexane and pentane were distilled from benzophenone ketyl as required. All polymerization reactions were carried out in a glass reactor as described previously (see Reference 5). Toluene for polymerization runs was distilled from sodium/potassium alloy. Nickel was chosen as the transition metal for the metal complex. L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) [L=N-(2,6-diisopropylphenyl)-2-(2,6-diisopropylphenylimino)propanamide](see Reference 5) and Ni(COD) 2  (see Reference 6) were synthesized as reported and purified by re-crystallization prior to polymerization use. NMR spectra were obtained using Varian Unity 400 or 500 spectrometers.  1 H NMR spectra of the polymers were obtained in mixed solvent (C 6 D 6 /1,2,4-trichlorobenzene 1:4 ratio in volume) at about 115° C. GPC analyses were done at Mitsubishi Chemical Corporation., Japan, in o-dichlorobenzene at about 135° C. 
     The quasi-living nature of the nickel catalyst, L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) and Ni(COD) 2 , for ethylene homo-polymerization was established based on the following criteria that are characteristic of living polymerization. 
     EXAMPLE 1 
     Molecular Weight Information 
     Time dependence studies of ethylene homo-polymerization were carried out. A toluene solution containing [L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 0.34 mM) and Ni(COD) 2  (about 0.85 mM) was pressurized with about 100 psi of ethylene and stirred at about 20° C. The reactor was depressurized after varied amounts of time and the reaction mixture was quenched immediately with acetone. The polyethylene polymers were then isolated by filtratration and were then dried in vacuum. 
     As typical of living polymerizations, a linear increase of the number average molecular weight (M n ) with time was observed, as shown in Table 1 and  FIG. 1 . 
     
       
         
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
                 TABLE 1 
               
               
                   
                   
               
               
                   
                 Time 
                   
                   
                   
               
               
                   
                 (min) 
                 M w   
                 M n   
                 M w /M n   
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 3 
                 3.67 × 10 4   
                 2.20 × 10 4   
                 1.6 
               
               
                   
                 5 
                 4.52 × 10 4   
                 3.40 × 10 4   
                 1.3 
               
               
                   
                 10 
                 1.25 × 10 5   
                 9.10 × 10 4   
                 1.4 
               
               
                   
                 20 
                 1.49 × 10 5   
                 1.10 × 10 5   
                 1.3 
               
               
                   
                   
               
             
          
         
       
     
     Table 1 shows the weight average molecular weight (M w ) and the number average molecular weight (M w ) as a function of time for ethylene homo-polymerization. L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 0.34 mM); Ni(COD) 2  (about 0.85 mM); about 100 psi ethylene pressure and about 20° C. temperature. Consistent with being a quasi-living polymerization system, narrow molecular weight distributions, M w /M n , in the range of about 1.3-1.6 were observed in all cases (see Table 1). 
     A living system has a number of active sites which equals the number of polymer chains. An estimate of the molecular weight of the polymer chains was obtained according to the calculations shown in Table 2 below. 
     For example, the 4 th  sample entry of Table 2 shows the total amount of ethylene consumed was about 1222 standard cubic cm (sec) which equals about 1.527 g (0.055 moles) of ethylene (1 sec=1.25×10 −3  g of ethylene at STP. STP is standard temperature and pressure, i.e., 0 C. and 760 mm of mercury (1.01 kPa). The L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) loading was about 10×10 −6  moles. Therefore, considering a process whereby the rate of initiation is on the order of propagation, the number of ethylene units in a polymer chain per active-site corresponds to about 5500 (0.055 moles of ethylene/10×10 −6  moles of Ni catalyst). The molecular weight of the polymer under these conditions corresponds to about 1.54×10 5  {5500×MW ethylene  (28 g/mole)}. For comparison, the experimental values were about 1.49×10 5  (M w ) and 1.10×10 5  (M n ). Similar estimates were made for other experiments shown by the 1 st , 2 nd  , and 3 rd  sample entries in Table 2. 
     Table 2 shows that the calculated molecular weights are in agreement with the experimental molecular weight values for the samples shown in Table 1 and described in Examples 2, 3, 4 and 5. Thus, the number of the active-sites corresponded to the number of initiator molecules used. 
     
       
         
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                 C 2 H 4   
                 Uptake 
                 Polymer 
                   
                 MW 
                 M w   
                 M n   
               
               
                 Mass flow 
                 Estimated Value 
                 Isolated 
                 Time 
                 Calc. 
                 Exp. 
                 Exp. 
               
               
                 (scc) 
                 (g) 
                 (g) 
                 (min) 
                 (10 4 ) 
                 (10 4 ) 
                 (10 4 ) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 133 
                 0.166 
                 0.140 
                 3 
                 1.66 
                 3.67 
                 2.20 
               
               
                 264 
                 0.329 
                 0.173 
                 5 
                 3.30 
                 4.52 
                 3.40 
               
               
                 986 
                 1.232 
                 1.096 
                 10 
                 12.3 
                 12.5 
                 9.10 
               
               
                 1222 
                 1.527 
                 1.322 
                 20 
                 15.4 
                 14.9 
                 11.0 
               
               
                   
               
             
          
         
       
     
     The data in  FIG. 1  and Tables 1-2 establish the quasi-living nature of the nickel catalyst with regards to ethylene homo-polymerization. 
     EXAMPLE 2 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 10 μmol; 1.00 g of 8.77 mM solution in toluene) and Ni(COD) 2  (about 25 μmol; 1.25 g of 17.6 mM solution in toluene) and toluene (about 23.7 g), such that the final volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 3 minutes and acetone was added to quench the polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. The reaction produced about 0.140 g of polyethylene polymer. The activity of the catalyst was about 499 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, 135° C.): M w =about 3.67×10 4 , M w /M n =about 1.6. DSC Analysis: T m =about 126.4° C.  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, about 115° C.): 10.2 methyl branches per 1000 methylene carbons. 
     EXAMPLE 3 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 10 μmol; 1.00 g of 8.77 mM solution in toluene) and Ni(COD) 2  (about 25 μmol; 1.25 g of 17.6 mM solution in toluene and toluene (about 23.7 g) such that the final volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 5 minutes and acetone was added to quench the polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. The reaction produced about 0.173 g of polyethylene polymer. The activity of the catalyst was about 495 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, about 135° C.): M w =about 4.52×10 4 , M w /M n =about 1.3. DSC Analysis: T m =about 127.9° C.  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, about 115° C.): 12.1 methyl branches per 1000 methylene carbons. 
     EXAMPLE 4 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 10 μmol; 1.00 g of 8.77 mM solution in toluene) and Ni(COD) 2  (about 25 μmol; 1.25 g of 17.6 mM solution in toluene) and toluene (about 23.7 g), such that the final volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 10 minutes and acetone was added to quench the polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. The reaction produced about 1.10 g of polyethylene polymer. The activity of the catalyst was about 821 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, about 135° C.): M w =about 1.25×10 5 , M w /M n =about 1.4. DSC Analysis: T m =about 123.6° C.  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, 115° C.): 14.2 methyl branches per 1000 methylene carbons. The GPC trace of the polyethylene obtained shows a unimodal molecular weight distribution is shown in  FIG. 2 . 
     EXAMPLE 5 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 10 μmol; 1.00 g of 8.77 mM solution in toluene) and Ni(COD) 2  (about 25 μmol, 1.25 g of 17.6 mM solution in toluene) and toluene (about 23.7 g) such that the final volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 20 minutes and acetone was added to quench to polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. The reaction produced about 1.322 g of polyethylene polymer. The activity of the catalyst was about 482 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, about 135° C.): MW=about 1.49×10 5 , M w /M n =about 1.3. DSC Analysis: T m =about 125.6° C.  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, about 115° C.): 7.8 methyl branches per 1000 methylene carbons. The GPC trace of the polyethylene obtained shows a unimodal molecular weight distribution is shown in  FIG. 2 . 
     EXAMPLE 6 
     The quasi-living nature of the nickel catalyst, for co-polymerization of ethylene with 5-norbornen-2-yl acetate was then tested. 
     Molecular Weight Information 
     Time dependence studies of ethylene co-polymerization with 5-norbornen-2-yl acetate were carried out. Specifically, a toluene solution containing L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 0.68 mM), Ni(COD) 2  (about 1.70 mM) and 5-norbornen-2-yl acetate (about 0.15 M) was pressurized with about 100 psi of ethylene and stirred at about 20° C. The reactor was depressurized after varied amounts of time, as seen in Table 3, and the reaction mixture was quenched immediately with acetone. The functionalized co-polymers were then isolated by filtration and were dried in vacuum. 
     In case of the ethylene/5-norbornen-2-yl acetate co-polymerization a linear increase of the number average molecular weight (Mn) with time was observed as shown in Table 3 and  FIG. 3 . Such a liner relationship is characteristics of a living polymerization. 
     
       
         
               
               
               
               
               
             
           
               
                   
                 TABLE 3 
               
               
                   
                   
               
               
                   
                 Time 
                   
                   
                   
               
               
                   
                 (min) 
                 M w   
                 M n   
                 M w /M n   
               
               
                   
                   
               
             
             
               
                   
                 15 
                 4.68 × 10 4   
                 3.90 × 10 4   
                 1.2 
               
               
                   
                 30 
                 6.71 × 10 4   
                 4.20 × 10 4   
                 1.6 
               
               
                   
                 60 
                 1.08 × 10 5   
                 8.00 × 10 4   
                 1.4 
               
               
                   
                 90 
                 1.56 × 10 5   
                 1.10 × 10 5   
                 1.4 
               
               
                   
                   
               
             
          
         
       
     
     Table 3 shows the weight average molecular weight (M w ) and number average molecular weight (M n ) as a function of time for ethylene co-polymerization with 5-norbornen-2-yl acetate. [L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 0.68 mM); Ni(COD) 2  (about 1.70 mM); 5-norbornen-2-yl acetate (about 0.15 M); about 100 psi ethylene pressure and about 20° C. temperature]. 
     Consistent with being a quasi-living polymerizing system, narrow molecular weight distributions in the range of about 1.2-1.6 were observed in all cases (Table 3). The data in  FIG. 3  and Table 3 are consistent with the quasi-living co-polymerization of ethylene with 5-norbornen-2-yl acetate initiated by a nickel catalyst formed by a combination of two neutral complexes, L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) and Ni(COD) 2 . 
     EXAMPLE 7 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 20 μmol 2.00 g of 8.77 mM solution in toluene), Ni(COD) 2  (about 50 μmol; 2.50 g of 17.6 mM solution in toluene), 5-norbornen-2-yl acetate (about 4.50 mmol; 3.00 g of 1.30 M solution in toluene) and toluene (about 18.45 g), such that the total volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 15 minutes and acetone was added to quench the polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. About 0.160 g of ethylene/5-norbornen-2-yl acetate co-polymer was obtained. The activity of the catalyst with respect to ethylene consumption was about 96 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, 135° C.): MW=about 4.68×10 4 , M w /M n =about 1.2. DSC Analysis: T m =broad glass transition.  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, about 115° C.): 22.8 methyl branches per 1000 methylene carbons. 7.3% incorporation of norbornenyl group. 
     EXAMPLE 8 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 20 μmol; 2.00 g of 8.77 mM solution in toluene), Ni(COD) 2  (about 50 μmol; 2.50 g of 17.6 mM solution in toluene), 5-norbornen-2-yl acetate (about 4.50 mmol; 3.00 g of 1.30 M solution in toluene) and toluene (about 18.45 g) such that the total volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 30 minutes and acetone was added to quench the polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. About 0.526 g of ethylene/5-norbornen-2-yl acetate co-polymer was obtained. The activity of the catalyst with respect to ethylene consumption was about 63 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, about 135° C.): M w =about 6.71×10 4 , M w /M n =about 1.6. DSC Analysis: T m =about 88° C. (broad).  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, about 115° C.): 30.7 methyl branches per 1000 methylene carbons. 14.5% incorporation of norbornenyl group. 
     EXAMPLE 9 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 20 μmol; 2.00 g of 8.77 mM solution in toluene), Ni(COD) 2  (about 50 μmol; 2.50 g of 17.6 mM solution in toluene), 5-norbornen-2-yl acetate (about 4.50 mmol; 3.00 g of 1.30 M solution in toluene) and toluene (about 18.45 g) such that the total volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 60 minutes and acetone was added to quench the polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. About 0.843 g of ethylene/5-norbornen-2-yl acetate co-polymer was obtained. The activity of the catalyst with respect to ethylene consumption was about 45 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, about 135° C.): M w =about 1.08×10 5 , M w /M n =about 1.4. DSC Analysis: T m =broad glass transition.  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, about 115° C.): 30.8 methyl branches per 1000 methylene carbons. 10.4% incorporation of norbornenyl group. 
     EXAMPLE 10 
     A glass reactor was loaded inside a glove box with L( i Pr 2 )Ni(CH 2 Ph)(PMe 3 ) (about 20 μmol; 2.00 g of 8.77 mM solution in toluene), Ni(COD) 2  (about 50 μmol; 2.50 g of 17.6 mM solution in toluene), 5-norbornen-2-yl acetate (about 4.50 mmol; 3.00 g of 1.30 M solution in toluene) and toluene (about 18.45 g) such that the total volume of the toluene solution was about 30 mL. The glass reactor was sealed inside the glove box and was attached to a vacuum/nitrogen line manifold. Ethylene was fed continuously into the reactor at about 100 psi and the pressurized reaction mixture was stirred at about 20° C. Ethylene was vented after about 90 minutes and acetone was added to quench the polymerization. The precipitated polymer was collected by filtration and dried under high vacuum overnight. About 1.031 g of ethylene/5norbornen-2-yl acetate co-polymer was obtained. The activity of the catalyst with respect to ethylene consumption was about 36 kg mol −1  h −1 . 
     Polymer Characterization: GPC Analysis (o-dichlorobenzene, about 135° C.): M w =about 1.56×10 5 , M w /M n =about 1.4. DSC Analysis: T m =broad glass transition.  1 H NMR (C 6 D 6 /1,2,4-trichlorobenzene, about 115° C.): 9.47 methyl branches per 1000 methylene carbons. 7.20% incorporation of norbornenyl group. 
     REFERENCES 
     The following references are hereby incorporated by reference: 1. Ittel, S. D.; Johnson, L. K.; Brookhart, M.  Chem. Rev.  2000, 100, 1169 (and references therein); 2. Younkin, T.; Connor, E. F.; Henderson, J. L; Friedrich, S. K.; Grubbs, R. H.; Bansleben, D. A.  Science,  2000, 287, 460; WO 9842664.; WO 9842665; 3. Coates, G. W.; Hustad, P. D.; Reinartz, S.  Angew. Chem. Int. Ed.  2002, 41, 2236 (and references therein); 4. Jansen, J. C.; Mendichi, R.; Locatelli, P.; Tritto, I.  Macromol. Rapid Commun.  2001, 22, 1394; 5. Lee, B. Y.; Bazan, G. C.; Vela, J.; Komon, Z. J. A.; Bu, X. J.  Am. Chem . Soc. 2001, 123, 5352; and 6. Schunn, R. A.; Ittel, S. D.; Cushing, M. A.  Inorg. Synth.  1990, 28, 94. 
     These and other changes and modifications are intended to be included within the scope of the invention. While for the sake of clarity and ease of description, several specific embodiments of the invention have been described; the scope of the invention is intended to be measured by the claims as set forth below. The description is not intended to be exhaustive or to limit the invention to the form disclosed. Other variations of the invention will be apparent in light of the disclosure and practice of the invention to one of ordinary skill in the art to which the invention applies.