The polyethylene produced by the nickel catalytic systems could potentially
become new functional materials because some of them have various types of alkyl
branches (from methyl to hexyl branches). Surprisingly, the obtained polyethylenes
are highly unique polyethylenes with narrow molecular polydispersity, but with
various alkyl branches in different numbers and different lengths of carbon chain.
Such polyethylenes with high molecular weights and narrow polydispersity can act
as elastomer materials and have high transparency. That would be an advantage of
using solely ethylene for highly branched polyethylene. These new polyethylenes
could be available from laboratory suppliers in kilogram quantities for any polymer
physicist to explore the properties and applications of such polyethylenes.
The chemistry of nickel-promoted ethylene polymerization is a new and interesting subject. More pre-catalyst models and catalytic behaviors are being explored,
and the obtained polyethylenes investigated for their properties and potential
applications. In assistance to polymeric chemists, more polymeric physicists are
expected to join the research and this will definitely draw attention from both
academic and industrial fields. These polyethylenes can provide a wide range of
properties in various applications.
Much innovative and extensive research into transition-metal complex
pre-catalysts in ethylene reactivity could not been included herein, but a few
examples of complex models have been discussed in a limited manner in order to
encourage more research and attract more consideration. The progress and
achievements, indicated by the selected results, emphasize two characteristic
species that can induce two different mechanistic polymerizations: highly linear
products (either oligomers or polyethylenes) formed by the catalytic systems of iron
or cobalt complexes, and branched polyethylenes formed by the catalytic systems
of nickel and palladium.
References
1. Ziegler K, Gellert HG, Zosel K, Lehmkuhl W, Pfohl W (1955) Angew Chem 67:424
2. Ziegler K, Holzkamp E, Breil H, Martin H (1955) Angew Chem 67:541–547
3. Natta G (1955) J Polym Sci 16:143–154
4. Natta G, Pino P, Corradini P, Danusso F, Mantica E, Mazzanti G, Moraglio G (1955) J Am
Chem Soc 77:1708–1710
5. McDaniel MP (2010) Adv Catal 53:123–606
6. Sinn H, Kaminsky W, Vollmer HJ (1980) Angew Chem Int Ed Engl 19:390
7. Kaminsky W (1996) Macromol Chem Phys 197:3907
8. Kaminsky W, Arndt M (1997) Adv Polym Sci 127:143
9. Johnson LK, Killian CM, Brookhart M (1995) J Am Chem Soc 117:6414
10. Killian CM, Tempel DJ, Johnson LK, Brookhart M (1996) J Am Chem Soc 118:11664
11. Svejda SA, Johnson LK, Brookhart M (1999) J Am Chem Soc 121:10634
12. Gates DP, Svejda SA, On ˜ate E, Killian CM, Johnson LK, White PS, Brookhart M (2000)
Macromolecules 33:2320
13. Britovsek GJP, Gibson VC, Kimberley BS, Maddox PJ, McTavish SJ, Solan GA, White AJP,
Williams DJ (1998) Chem Commun 1998:849
176
W.-H. Sun
become new functional materials because some of them have various types of alkyl
branches (from methyl to hexyl branches). Surprisingly, the obtained polyethylenes
are highly unique polyethylenes with narrow molecular polydispersity, but with
various alkyl branches in different numbers and different lengths of carbon chain.
Such polyethylenes with high molecular weights and narrow polydispersity can act
as elastomer materials and have high transparency. That would be an advantage of
using solely ethylene for highly branched polyethylene. These new polyethylenes
could be available from laboratory suppliers in kilogram quantities for any polymer
physicist to explore the properties and applications of such polyethylenes.
The chemistry of nickel-promoted ethylene polymerization is a new and interesting subject. More pre-catalyst models and catalytic behaviors are being explored,
and the obtained polyethylenes investigated for their properties and potential
applications. In assistance to polymeric chemists, more polymeric physicists are
expected to join the research and this will definitely draw attention from both
academic and industrial fields. These polyethylenes can provide a wide range of
properties in various applications.
Much innovative and extensive research into transition-metal complex
pre-catalysts in ethylene reactivity could not been included herein, but a few
examples of complex models have been discussed in a limited manner in order to
encourage more research and attract more consideration. The progress and
achievements, indicated by the selected results, emphasize two characteristic
species that can induce two different mechanistic polymerizations: highly linear
products (either oligomers or polyethylenes) formed by the catalytic systems of iron
or cobalt complexes, and branched polyethylenes formed by the catalytic systems
of nickel and palladium.
References
1. Ziegler K, Gellert HG, Zosel K, Lehmkuhl W, Pfohl W (1955) Angew Chem 67:424
2. Ziegler K, Holzkamp E, Breil H, Martin H (1955) Angew Chem 67:541–547
3. Natta G (1955) J Polym Sci 16:143–154
4. Natta G, Pino P, Corradini P, Danusso F, Mantica E, Mazzanti G, Moraglio G (1955) J Am
Chem Soc 77:1708–1710
5. McDaniel MP (2010) Adv Catal 53:123–606
6. Sinn H, Kaminsky W, Vollmer HJ (1980) Angew Chem Int Ed Engl 19:390
7. Kaminsky W (1996) Macromol Chem Phys 197:3907
8. Kaminsky W, Arndt M (1997) Adv Polym Sci 127:143
9. Johnson LK, Killian CM, Brookhart M (1995) J Am Chem Soc 117:6414
10. Killian CM, Tempel DJ, Johnson LK, Brookhart M (1996) J Am Chem Soc 118:11664
11. Svejda SA, Johnson LK, Brookhart M (1999) J Am Chem Soc 121:10634
12. Gates DP, Svejda SA, On ˜ate E, Killian CM, Johnson LK, White PS, Brookhart M (2000)
Macromolecules 33:2320
13. Britovsek GJP, Gibson VC, Kimberley BS, Maddox PJ, McTavish SJ, Solan GA, White AJP,
Williams DJ (1998) Chem Commun 1998:849
176
W.-H. Sun