Distribution of monomer units in butadiene-isoprene copolymers

Lobach, M. I.; Poletayeva, I.A.; Khatchaturov, A.S.; Druz, N.N.; Kormer, V. A.

doi:10.1016/0032-3861(77)90123-9

Cited by 25 publications

(12 citation statements)

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“…The representative 13 C NMR spectra of copolymers having butadiene contents of around 50% are shown in Figure . The peaks can be assigned to different monomer diad carbons according to the literature . The signals 6, 5, and 1 located at 26.4, 27.4, and 32.2 ppm, respectively, which are due to the dyads composed of the identical monomers, clearly show the primary cis ‐1,4 configuration in both butadiene and isoprene units.…”

Section: Resultsmentioning

confidence: 99%

“…The peaks can be assigned to different monomer diad carbons according to the literature. [ 36 ] The signals 6, 5, and 1 located at 26.4, 27.4, and 32.2 ppm, respectively, which are due to the dyads composed of the identical monomers, clearly show the primary cis -1,4 confi guration in both butadiene and isoprene units. The other four signals (2, 3, 4, and 7) are characteristics of the carbon atoms of methylene groups at alternating monomer dyads in cis confi guration.…”

Section: /Mao/ T-bucl Ternary Systemmentioning

confidence: 96%

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Novel Methylaluminoxane‐Activated Neodymium Isopropoxide Catalysts for 1,3‐Butadiene Polymerization and 1,3‐Butadiene/Isoprene Copolymerization

Dong

Masuda

2013

Macro Chemistry & Physics

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The homo‐ and copolymerizations of 1,3‐butadiene and isoprene are examined by using neodymium isopropoxide [Nd(Oi‐Pr)3] as a catalyst, in combination with a methylaluminoxane (MAO) cocatalyst. In the homopolymerization of 1,3‐butadiene, the binary Nd(Oi‐Pr)3/MAO catalyst works quite effectively, to afford polymers with high molecular weight (M‾n ≈ 105 g mol‐1), narrow molecular‐weight distribution (MWD) (M‾w/M‾n = 1.4–1.6), and cis‐1,4‐rich structure (87–96%). Ternary catalysts that further contain chlorine sources enhance both catalytic activity and cis‐1,4 selectivity. In the copolymerization of 1,3‐butadiene and isoprene, the copolymers feature high M‾n, unimodal gel‐permeation chromatography (GPC) profiles, and narrow MWD. Most importantly, the ternary Nd(Oi‐Pr)3/MAO/t‐BuCl catalyst affords a copolymer with high cis‐1,4 content in both monomer units (>95%).

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Section: Resultsmentioning

confidence: 99%

Section: /Mao/ T-bucl Ternary Systemmentioning

confidence: 96%

Novel Methylaluminoxane‐Activated Neodymium Isopropoxide Catalysts for 1,3‐Butadiene Polymerization and 1,3‐Butadiene/Isoprene Copolymerization

Dong

Masuda

2013

Macro Chemistry & Physics

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“…The 13 C‐NMR spectra of the copolymers are shown in Figure 5, and the assignments of the peaks and the dyad concentrations calculated from the 13 C‐NMR spectra are listed in Tables VI and VII, respectively 20, 21…”

Section: Resultsmentioning

confidence: 99%

Synthesis of a high‐trans 1,4‐butadiene/isoprene copolymers with supported titanium catalysts

Bao-chen

Jiao

et al. 2003

J of Applied Polymer Sci

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ABSTRACT:The copolymerization of butadiene (Bd) and isoprene (Ip) with a supported titanium-triisobutyl aluminum catalyst system was studied. An analysis using differential scanning calorimetry, X-ray diffraction, and 13 C-NMR spectra indicated that products with 25-60 mol % Bd units were random copolymers and that the melting temperatures and glass-transition temperatures (Tg) were 30 -40 and Ϫ74°C (or thereabout), respectively, which were very similar to those of natural rubber. The chemical structure of these copolymers was characterized by a high-trans 1,4-configuration: the trans 1,4-content of Ip units was greater than 98%, and the trans 1,4-content of Bd units was greater than 90%. The reactivity ratio of Bd was greater than that of Ip (r Bd ϭ 5.7 and r Ip ϭ 0.17). The sequence distribution of the monomer units of the copolymers followed a first-order Markov statistical model.

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“…Lobach and coworkers [80] prepared copolymers of isoprene and butadiene in which monomer units had either predominantly 1,4-cis-or 1,4-trans-configurations and investigated their cmr spectra. Assignments were made for the various aliphatic carbon resonances observed.…”

Section: Isoprene-butadiene Copolymersmentioning

confidence: 99%

NMR Analysis of Stereo Regular Copolymers

Harwood

1979

Preparation and Properties of Stereoregular Polymers

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Stereoregular copolymers are formed by the chemical modification of stereoregular polymers, by copolymerizations of ~-olefins in the presence of stereoregulating catalysts and by ring opening copolymerizations of chiral monomers. Also appropriate for consideration are polydienes containing cis-l,4-and trans-l,4-units as well as those containing 1,2-{or 3,4-) and 1,4-units. Analysis of such copolymers by NMR spectroscopy provides information about their compositions and the arrangement of monomer units along their chains. Such information is valuable for understanding the chemical behavior of stereoregular polymers and the mechanisms of stereoregular polymerization processes. STRUCTURAL FEATURES PRESENT IN STEREOREGULAR COPOLYMERSIf a stereoregular copolymer containing A and B monomer units is considered, then some of its structural features that can be measured by NMR spectroscopy can be listed as follows.

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Distribution of monomer units in butadiene-isoprene copolymers

Cited by 25 publications

References 1 publication

Novel Methylaluminoxane‐Activated Neodymium Isopropoxide Catalysts for 1,3‐Butadiene Polymerization and 1,3‐Butadiene/Isoprene Copolymerization

Novel Methylaluminoxane‐Activated Neodymium Isopropoxide Catalysts for 1,3‐Butadiene Polymerization and 1,3‐Butadiene/Isoprene Copolymerization

Synthesis of a high‐trans 1,4‐butadiene/isoprene copolymers with supported titanium catalysts

NMR Analysis of Stereo Regular Copolymers

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