High-Temperature Living Copolymerization of Ethylene with Norbornene by Titanium Complexes Bearing Bidentate [O, P] Ligands

He, Lipeng; Liu, Jingyu; Li, Yanguo; Liu, Sanrong; Li, Yuesheng

doi:10.1021/ma901285a

Cited by 59 publications

(43 citation statements)

References 27 publications

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“…These copolymers typically exhibit high glass‐like clarity, good solvent resistance, high thermal stability, and facile processability that make such copolymers attractive as high‐tech engineering materials. Despite the importance of these copolymers in various fields owing to their extraordinary material properties, there are only a few examples of catalysts that give living E‐ co ‐N copolymerization 39–52…”

Section: Introductionmentioning

confidence: 99%

Thermosetting foam with a high bio‐based content from acrylated epoxidized soybean oil and carbon dioxide

Bonnaillie

Wool

2007

J of Applied Polymer Sci

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A resilient, thermosetting foam system with a bio-based content of 96 wt % (resulting in 81% of C 14 ) was successfully developed. We implemented a pressurized carbon dioxide foaming process that produces polymeric foams from acrylated epoxidized soybean oil (AESO). A study of the cell dynamics of uncured CO 2 / AESO foams proved useful to optimize cure conditions. During collapse, the foam's bulk density increased linearly with time, and the cell size and cell density exhibited power-law degradation rates. Also, low temperature foaming and cure (i.e. high viscosity) are desirable to minimize foam cell degradation. The AESO was cured with a freeradical initiator (tert-butyl peroxy-2-ethyl hexanoate, T i $ 608C). Cobalt naphtenate was used as an accelerator to promote quick foam cure at lower temperature (40-508C). The foam's density was controlled by the carbon dioxide pressure inside the reactor and by the vacuum applied during cure. The viscosity increased linearly during polymerization. The viscosity was proportional to the extent of reaction before gelation, and the cured foam's structure showed a dependence on the time of vacuum application. The average cell size increased and the cell density decreased with foam expansion at a low extent of cure; however, the foam expansion became limited and unhomogeneous with advanced reaction. When vacuum was applied at an intermediate viscosity, samples with densities $ 0.25 g/cm 3 were obtained with small (<1 mm) homogeneous cells. The mechanical properties were promising, with a compressive strength of $ 1 MPa and a compressive modulus of $ 20 MPa. The new foams are biocompatible.

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Section: Introductionmentioning

confidence: 99%

Thermosetting foam with a high bio‐based content from acrylated epoxidized soybean oil and carbon dioxide

Bonnaillie

Wool

2007

J of Applied Polymer Sci

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“…This is the case if the process evolves only by the attachment and detachment of monomeric units to the chain, for instance with a catalyst located at the tip of the copolymer. Free living copolymerization is most important in polymer science where macromolecules composed of various types of monomeric units can be synthesized with newly advanced organometallic catalyst systems [9][10][11][12][13][14][15][16][17].…”

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confidence: 99%

Growth and Dissolution of Macromolecular Markov Chains

Gaspard

2016

J Stat Phys

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The kinetics and thermodynamics of free living copolymerization are studied for processes with rates depending on k monomeric units of the macromolecular chain behind the unit that is attached or detached. In this case, the sequence of monomeric units in the growing copolymer is a k th -order Markov chain. In the regime of steady growth, the statistical properties of the sequence are determined analytically in terms of the attachment and detachment rates. In this way, the mean growth velocity as well as the thermodynamic entropy production and the sequence disorder can be calculated systematically. These different properties are also investigated in the regime of depolymerization where the macromolecular chain is dissolved by the surrounding solution. In this regime, the entropy production is shown to satisfy Landauer's principle.

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“…Gibson and his coworkers reported a series of bis(phosphanylphenoxide) group 4 metal dichloride complexes, and further suggested that the use of ancillary ligands with softer L donors, such as phosphorus and sulfur, might offer beneficial stabilization of the highly reactive metal center [41,42]. Subsequently, our group found that high-temperature living ethylene/norbornene copolymerization could be achieved by using bis(phenoxy-phosphine)-titanium complexes as the catalysts in the presence of MMAO [43].…”

Section: Introductionmentioning

confidence: 92%

Phosphine-Thiophenolate Half-Titanocene Chlorides: Synthesis, Structure, and Their Application in Ethylene (Co-)Polymerization

Tang

Liu

2013

Catalysts

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A series of novel half-titanocene complexes CpTiCl 2 [S-2-R-6-(PPh 2 )C 6 H 3 ] (Cp = C 5 H 5 , 2a, R = H; 2b, R = Ph; 2c, R = SiMe 3 ) have been synthesized by treating CpTiCl 3 with the sodium of the ligands, 2-R-6-(PPh 2 )C 6 H 3 SNa, which were prepared by the corresponding ligands and NaH. These complexes have been characterized by 1 H, 13C and 31 P NMR as well as elemental analyses. Structures for 2a-b were further confirmed by X-ray crystallography. Complexes 2a-b adopt five-coordinate, distorted square-pyramid geometry around the titanium center, in which the equatorial positions are occupied by sulfur and phosphorus atoms of the chelating phosphine-thiophenolate and two chlorine atoms, and the cyclopentadienyl ring is coordinated on the axial position. The complexes 2a-c were investigated as the catalysts for ethylene polymerization and copolymerization of ethylene with norbornene in the presence of MMAO or Ph 3 CB(C 6 F 5 ) 4 / i Bu 3 Al as the cocatalyst. All complexes exhibited low to moderate activities towards homopolymerization of ethylene. However, they displayed moderate to high activities towards copolymerization of ethylene with norbornene.

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High-Temperature Living Copolymerization of Ethylene with Norbornene by Titanium Complexes Bearing Bidentate [O, P] Ligands

Cited by 59 publications

References 27 publications

Thermosetting foam with a high bio‐based content from acrylated epoxidized soybean oil and carbon dioxide

Thermosetting foam with a high bio‐based content from acrylated epoxidized soybean oil and carbon dioxide

Growth and Dissolution of Macromolecular Markov Chains

Phosphine-Thiophenolate Half-Titanocene Chlorides: Synthesis, Structure, and Their Application in Ethylene (Co-)Polymerization

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