Structure of Polybutadienes Synthesised with a New Catalyst System, 3. Random Copolymers oftrans-1,4- and 1,2-Polybutadiene

Антипов, Е. М.; Schklyaruk, Boris F.; Stamm, Manfred; Fischer, Erhard W.

doi:10.1002/1521-3935(20010101)202:1<82::aid-macp82>3.0.co;2-7

Cited by 7 publications

(1 citation statement)

References 13 publications

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“…S3 and Fig. The peaks at 44.7 and 97.0 °C are corresponded to the transitions from the crystal to the mesophase and from the mesophase to the melt, 48,49 Different amount of acetone, which is a good solvent for PCL blocks but a poor solvent for TPB blocks, was dropped gradually into the prepared solution. The signals at 2.03 ppm and 5.41 ppm are assigned to the methylene and methyne protons of the trans-1,4 unit, respectively.…”

Section: Synthesis Of the Tpb-b-pcl And Tpb-b-pla Copolymersmentioning

confidence: 99%

Highly trans-1,4-stereoselective coordination chain transfer polymerization of 1,3-butadiene and copolymerization with cyclic esters by a neodymium-based catalyst system

et al. 2015

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selective coordination chain transfer polymerization of 1,3-butaidiene was achieved by Nd(Oi-Pr)3/Mg(n-Bu)2 catalyst, affording polybutadienes having high trans-1,4 contents (ca. 96%), moderate molecular weight (Mn = 1.0-2.3 × 10 4 ), and narrow polydispersity (Mw/Mn~1.7). In the system, Mg(n-Bu)2 acted as both cocatalyst and chain transfer agent, and the calculated transfer efficiencies of Mg(n-Bu)2 were 27-34%. The produced living polybutadiene could further initiate the ring-opening polymerization of ε-CL/lactide to give TPB-b-PCL/PLA copolymers in a controlled fashion. The crystalline amphiphilic copolymers (TPB-b-PCL/PLA) were subsequently applied to investigate their self-assembly behavior by adding a selective solvent into polymer/cosolvent solution. The polymer plates composed of a crystallized TPB core and PCL/PLA brushes were obtained by the crystallization-driven self-assembly. Moreover, the morphology of the polymers underwent nano-sized plates to micro-sized plates with the increasing addition of the selective solvent.Highly trans-1,4 stereoregular polybutadiene (TPB) was obtained by coordination chain transfer polymerization and novel amphiphilic copolymers (TPB-b-PCL/PLA) were successfully synthesized.

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Section: Synthesis Of the Tpb-b-pcl And Tpb-b-pla Copolymersmentioning

confidence: 99%

Highly trans-1,4-stereoselective coordination chain transfer polymerization of 1,3-butadiene and copolymerization with cyclic esters by a neodymium-based catalyst system

et al. 2015

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Microstructure‐thermal property relationship of high trans‐1,4‐poly(butadiene) produced by anionic polymerization of 1,3‐butadiene using an initiator composed of alkyl aluminum, n‐butyl lithium, and barium alkoxide

Benvenuta‐Tapia

Tenorio-López

Herrera‐Nájera

et al. 2008

Polymer Engineering & Sci

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This article deals with the characterization of high trans‐1,4‐poly(butadiene) (TPBD) prepared by means of an anionic polymerization using an initiator composed of alkyl aluminum, n‐butyl lithium, and barium alkoxide. By controlling both initiator composition and polymerization temperature, a set of TPBD was prepared with well‐known number of 1,4‐trans units, molecular weight distribution, and average molecular weight. Analyses by differential scanning calorimetry and diffraction of wide‐angle X‐rays showed a direct relationship between the microstructure of the polymer and its thermal properties. By increasing the number of 1,4‐trans units (70–90%), the crystallinity of the polymer was increased (10–30%); polymers with less than 65% of 1,4‐trans units were amorphous, whereas TPBD with a number of 1,4‐trans units greater than 80% were polymorphous and presented two endothermic transitions. Summing up, the results presented in this article indicate that cyclohexane solutions of alkyl aluminum, n‐butyl lithium, and barium alkoxide allow produce polybutadienes with enough amount of 1,4‐trans units to display a regular microstructure that makes them susceptible to experience‐induced crystallization, likewise at a reaction rate similar to that observed for the commercial production of poly(butadiene) with n‐butyl lithium. POLYM. ENG. SCI., 2009. © 2008 Society of Plastics Engineers

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Mesomorphism in polymers and its mechanotropic variety for polyethylene in binary polymer blends based on it

Антипов

Noordermeer

2005

J Eng Phys Thermophys

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For the first time, an attempt has been made to illustrate the diversity of different forms of mesomorphism in flexible-and rigid-chain linear polymers whose macromolecules do not contain mesogenic groups. The emphasis has been on description of new structural varieties that are equilibrium mesophases from the thermodynamic viewpoint. Concrete examples of unusual two-dimensional and one-dimensional forms of ordering, recently found by the authors for a number of high-molecular-weight compounds, have been given.The originality of modern concepts of the structure of high-molecular-weight compounds (HMWCs) lies in the increasingly greater departure of researchers from the two-phase model, according to which there can exist only two physical states -the crystalline state (3D -long-range order) and the amorphous state (3D -near-range order).It is surprising how common the universally accepted viewpoint of the single-step fusion of a crystal as of the process typical of the condensed state of a substance has become. We consider the actual situation from a somewhat different viewpoint.The simplest crystals constructed from spherically shaped elements (for example, metals) are known to be characterized by the long-range position order in three independent dimensions. If the elements constituting the crystal lattice have an anisotropy of shape (rods or disks), orientation elements of order are added to the three position degrees of freedom. If such rods or disks have lateral substitutes, one should also take into account the rotation forms of ordering. Thus, the structural hierarchy of even a low-molecular-weight crystal can appear rather complex and can possess a rich combinatorics of different "degrees of freedom" or elements of order. As far as polymers whose macromolecules have a complex structure in themselves, possess a pronounced shape anisotropy, and are often characterized by cylindrical symmetry, here one should expect dramatic thermodynamic events "on the path from a crystal to a liquid."The question arises: from where does it follow that the entire rich hierarchy of order must be destroyed suddenly, simultaneously, at a single temperature point (and, needless to say, for a certain fixed value of pressure) in heating to form a totally "structureless" melt or, more precisely, a state characterized only by the near-range order in all three dimensions? It is much more natural to expect a step-by-step "melting" of some degrees of freedom or others in heating of the system, which means a multistep process of disordering, each step of which is separated from another by a phase transition of the first kind. This, in turn, points to the possibility of observing a sequence of polymorphic transformations of intermediate but simultaneously equilibrium structures in the temperature series (or on the pressure scale) with a gradual but discrete loss of the solid-state properties of a truly crystalline substance and approach to a truly liquid state. And that is the case. Each of such structures was considered first as an "exc...

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Structure of Polybutadienes Synthesised with a New Catalyst System, 3. Random Copolymers oftrans-1,4- and 1,2-Polybutadiene

Cited by 7 publications

References 13 publications

Highly trans-1,4-stereoselective coordination chain transfer polymerization of 1,3-butadiene and copolymerization with cyclic esters by a neodymium-based catalyst system

Highly trans-1,4-stereoselective coordination chain transfer polymerization of 1,3-butadiene and copolymerization with cyclic esters by a neodymium-based catalyst system

Microstructure‐thermal property relationship of high trans‐1,4‐poly(butadiene) produced by anionic polymerization of 1,3‐butadiene using an initiator composed of alkyl aluminum, n‐butyl lithium, and barium alkoxide

Mesomorphism in polymers and its mechanotropic variety for polyethylene in binary polymer blends based on it

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