Stereospecific Polymerizations of Conjugated Diolefins. Note V: Preparation and Properties of Isotactic 1,2-Polybutadiene

Natta, G.; Porri, L.; Zanini, G.; Palvarini, A.

doi:10.1016/b978-1-4831-9882-8.50078-6

Cited by 10 publications

(19 citation statements)

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“…In contrast, soluble chromium‐based catalysts tend to produce 1,2‐polymers in diene polymerization. Chromium compounds such as Cr(acetylacetonate) 3 , Cr(CNPh) 6 , Cr(CO) 6 and Cr(CO) 3 (pyridine) 3 in combination with alkylaluminium compounds were reported to catalyze the 1,2‐polymerization of BD 12–15. Alkylchromium compounds such as CrEt 3 and CrPh 3 ·3THF (where THF is tetrahydrofuran) were reported to produce a mixture of 1,2‐ and trans ‐1,4‐PBD 16.…”

Section: Introductionmentioning

confidence: 99%

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Nakayama

Sogo

Cai

et al. 2011

Polymer International

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Chromium complexes with N,N,N‐tridentate ligands, LCrCl3 (L = 2,6‐bis{(4S)‐(−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine (1), 2,2′:6′,2″‐terpyridine (2), and 4,4′,4″‐tri‐tert‐butyl‐2,2′:6′,2″‐terpyridine (3)), were prepared. The structures of 1 and 2 were determined by X‐ray crystallography. Upon activation with modified methylaluminoxane (MMAO), 1 catalyzed the polymerization of 1,3‐butadiene, while 2 and 3 was inactive. The obtained poly(1,3‐butadiene) obtained with 1‐MMAO was found to have completely trans‐1,4 structure. The 1‐MMAO system also showed catalytic activity for the polymerization of isoprene to give polyisoprene with trans‐1,4 (68%) and cis‐1,4 (32%) structure. Copyright © 2011 Society of Chemical Industry

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Section: Introductionmentioning

confidence: 99%

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Nakayama

Sogo

Cai

et al. 2011

Polymer International

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“…Although a number of catalytic systems have been reported to conduct stereospecific polymerization of 1,3-butadiene for cis-1,4, [1][2][3][4][5][6][7][8][9][10][11] trans-1,4, [12,13] syndiotactic-1,2, [14][15][16] atactic-1,2, [17] and isotactic-1,2, [18] polymers, only limited examples are reported for both stereospecific and living polymerization in 1,3-butadiene. [1][2][3][4] In transition metalcatalyzed polymerization, the addition of a Lewis base is sometimes very effective in the control of the activity, the stereospecificity, and the livingness of the system.…”

Section: Introductionmentioning

confidence: 99%

Additive Effect of Triphenylphosphine on the Living Polymerization of 1,3‐Butadiene with a Cobalt Dichloride‐Methylaluminoxane Catalytic System

Nath

Shiono

Ikeda

2003

Macro Chemistry & Physics

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The additive effect of triphenylphosphine (Ph3P) was investigated in 1,3‐butadiene polymerization with cobalt dichloride (CoCl2) activated by methylaluminoxane (MAO); the catalytic system resulted in slowly‐initiated living polymerization with a high cis‐1,4 content (about 99%) at 0 °C. The polymerization behavior, such as the relationship of polymer yield and number‐average molecular weight ($\overline M _{\rm n}$) with polymerization time, was dependent on the amount of Ph3P added. In the presence of a small amount of Ph3P (Ph3P/Co = 0.025), the kinetic behavior qualitatively resembled that observed in the absence of Ph3P, which indicated that the catalytic system conducted slowly‐initiated living polymerization. An increase in the amount of Ph3P (Ph3P/Co > 0.025), however, caused chain transfer reaction. The 1H NMR analysis of the produced polymers showed that Ph3P changed the microtacticity from 99% of cis‐1,4 to 88% of 1,2‐unit, depending on the amount of Ph3P added. At the maximum amount of Ph3P (Ph3P/Co = 0.025) necessary for maintaining the livingness of the propagating species, 14% of the 1,2‐inserted unit was incorporated at the expense of the cis‐1,4‐inserted unit. The addition of Ph3P (Ph3P/Co = 0.025) during the polymerization did not affect the livingness and gave a regio‐block copolymer of 1,3‐butadiene.

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“…Natta et al17 pointed out that the stereoregularity of the poly(Bd) depended on the catalyst aging time in the polymerization of Bd with the Cr‐based catalyst, and isotactic 1,2‐poly(Bd) was synthesized by a longer aging time. The effects of the catalyst aging on the polymerization of Bd with the Cr(acac) 3 ‐AlMe 3 catalyst were examined, and the results are listed in Table VI.…”

Section: Resultsmentioning

confidence: 99%

“…On the other hand, 1,2 polymerizations of Bd were also investigated. Researchers found that Cr, Mo, and Nd salts containing nonhalogen ligands favor the formation of 1,2‐poly(Bd) 12–18. 1,2‐Poly(Bd) has stereoregularity, as well as polyolefins; and syndiotactic 1,2‐poly(Bd) was synthesized with CoCl 2 ‐AlEt 3 , CoBr 2 ‐(PPh 3 ) 2 ‐Al(i‐Bu) 3 ‐H 2 O, V(acac) 3 ‐AlEt 3 , and Ti(OBu) 4 ‐AlEt 3 catalysts 12–16.…”

Section: Introductionmentioning

confidence: 99%

“…1,2‐Poly(Bd) has stereoregularity, as well as polyolefins; and syndiotactic 1,2‐poly(Bd) was synthesized with CoCl 2 ‐AlEt 3 , CoBr 2 ‐(PPh 3 ) 2 ‐Al(i‐Bu) 3 ‐H 2 O, V(acac) 3 ‐AlEt 3 , and Ti(OBu) 4 ‐AlEt 3 catalysts 12–16. Natta et al17, 18 reported that isotactic 1,2‐poly(Bd) could be synthesized from the polymerization of Bd with Cr(CNC 6 H 5 ) 6 ‐AlEt 3 and chromium(III) acetylacetonato [Cr(acac) 3 ]‐AlEt 3 catalysts, depending on the polymerization conditions, but the polymers were not determined by NMR spectroscopy. To elucidate this point we investigated the polymerization of Bd with Cr(acac) 3 in combination with various AlR 3 compounds, including methylaluminoxane (MAO), and the polymer structure was estimated by NMR spectroscopy.…”

Section: Introductionmentioning

confidence: 99%

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1,2-Polymerization of 1,3-butadiene with Cr(acac)3-alkylaluminum catalysts

Endo

Uchida

2000

J. Appl. Polym. Sci.

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The polymerization of butadiene (Bd) with chromium(III) acetylacetonato [Cr(acac)3]‐trialkylaluminum (AlR3) or methylaluminoxane (MAO) catalysts was investigated for the synthesis of 1,2‐poly(Bd). The polymerization of Bd was found to proceed with Cr(acac)3‐AlR3 (R‐Me, Et, i‐Bu) catalysts to give poly(Bd) with a high 1,2‐vinyl content, but highly isotactic 1,2‐poly(Bd) was not synthesized. The Cr(acac)3‐MAO catalyst gave a polymer consisting of low 1,2 units. The effects of the Al/Cr mole ratios on the polymerization of Bd with the Cr(acac)3‐AlR3 catalysts were observed. With an increase of Al/Cr mole ratios, the isotactic (mm) content of the polymer increased but the 1,2‐vinyl contents decreased. The effects of the aging time and temperatures of the catalysts on the polymerization of Bd with the Cr(acac)3‐AlR3 catalysts were also observed, and the lower polymerization temperature and the prolonged aging time were favored to produce the 1,2‐vinyl structure. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 78: 1621–1627, 2000

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Stereospecific Polymerizations of Conjugated Diolefins. Note V: Preparation and Properties of Isotactic 1,2-Polybutadiene

Cited by 10 publications

References 0 publications

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Highly trans‐1,4‐specific polymerization of 1,3‐butadiene catalyzed by [2,6‐bis{(4S)‐ (−)‐isopropyl‐2‐oxazolin‐2‐yl}pyridine] chromium complex activated with modified methylaluminoxane

Additive Effect of Triphenylphosphine on the Living Polymerization of 1,3‐Butadiene with a Cobalt Dichloride‐Methylaluminoxane Catalytic System

1,2-Polymerization of 1,3-butadiene with Cr(acac)3-alkylaluminum catalysts

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