Preparation and Morphology of Model Graft Copolymers of the A3B2 Type with Different Graft Junction Points

Takano, Atsushi; Kondo, Kazunori; Ueno, Masaya; Ito, Kazuya; Kawahara, Seiichi; Isono, Yoshinobu; Suzuki, Jirô; Matsushita, Yushu

doi:10.1295/polymj.33.732

Cited by 25 publications

(38 citation statements)

References 15 publications

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“…Tetrahydrofuran (THF), styrene, styrene-d 8 (Aldrich Chemcal Co.), and 1,1-diphenylethylene (DPE) were purified using the same methods as reported previously. 35 1-[3-(3-chloropropyl)phenyl]-1-phenylethylene (I) as described below was synthesized by the Li 2 CuCl 4 -mediated coupling reaction of a Grignard reagent of 1-(3-bromophenyl)-1-phenylethylene with 1-bromo-3-chloropropane. The detailed synthetic procedure of I was followed by the same manners as reported by Hayashi et al, 36 and the purification of I was in the same ways as reported previously.…”

Section: Methodsmentioning

confidence: 99%

“…The detailed synthetic procedure of I was followed by the same manners as reported by Hayashi et al, 36 and the purification of I was in the same ways as reported previously. 31,35,37 …”

Section: Methodsmentioning

confidence: 99%

“…After being freezedried, the telechelic polymers were transferred into vacuum glass apparatuses and then diluted with purified THF for subsequent cyclization reactions. 35,37 Excess amount of potassium naphthalenide, used as the linking agent, was introduced into THF solutions (0.05-0.2 (w/v)%) of the telechelic polymers at room temperature, and stirred for 1 d. The stoichiometry of the molar amount of end C=C groups on linear telechelic polymers and that of the lithium naphthalenide is [Li]/[C=C] ! 5.…”

Section: Preparation Of Cyclic Polystyrenesmentioning

confidence: 99%

“…Weight-average molecular weight, M w , was measured by light scattering in THF at 35 C with a multi-angle laser light scattering apparatus, MALLS Dawn-EOS of Wyatt Technology, Co. Molecular weight distribution, M w =M n , was determined by SEC with a set of three G 4000HHR columns (300 Â 7:8 mm I.D., Tosoh. Co.).…”

Section: Molecular Characterizationmentioning

confidence: 99%

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Preparation and Characterization of Cyclic Polystyrenes

Cho

Masuoka

Koguchi

et al. 2005

Polym J

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ABSTRACT:Macrocyclic polystyrenes with various molecular weight were prepared by the reaction of linear polystyrene having two end vinyl groups and potassium naphthalenide as a coupling agent. Intermolecular side reactions produced higher molecular weight polycondensates and undesirable chain termination reactions also produced linear precursors in addition to the designed molecules. In order to isolate cyclic polymers from the ring closure reaction mixtures, preparative size exclusion chromatography (SEC) method was employed. The purity of SEC-fractionated cyclic polystyrenes was rigorously examined by liquid chromatography at the critical condition (LCCC) and interaction chromatography (IC). After SEC-fractionation, we obtained large amount of highly pure cyclic polymers, though high molecular weight cyclic polymers contain very small amount of linear precursor (< 5%). The purity and isotope effect on reversed-phase liquid chromatography (RPLC) were also rigorously investigated by preparing a deuterated cyclic polystyrene. [DOI 10.1295/polymj.37.506] KEY WORDS Cyclic Polystyrene / GPC Fractionation / LCCC / Isotope Effect / Cyclic macromolecules are of great interest in the investigation of the influence of cyclization on their solution, melt, and solid-state properties. Various physical properties of cyclic polymers have been predicted not only by theoretical methods 1-4 but also by computer simulation studies, 5-7 while they have also been examined experimentally. [8][9][10][11][12][13][14] Cyclic polymers were usually synthesized by the coupling reaction between living precursor polymers with functional groups on both ends and bifunctional linking agents. For example, polystyrenes 9,15-19 and poly(2-vinylpyridine)s 20,21 have been synthesized by this method. Furthermore, , !-heterobifunctional polymers have been used for the synthesis of cyclic polymers.22-24 However, side reactions produce linear precursor polymers, and intermolecular reactions simultaneously produce dimeric and higher molecular weight linear polycondensates. Therefore, it is very difficult to obtain pure cyclic polymers directly, and fractionation is necessary in order to obtain cyclic polymers with high purity. For the isolation of cyclic polymers from the ring closure reaction mixtures, two major fractionation methods have been employed: fractional precipitation method 9,14,[16][17][18] and preparative size exclusion chromatography (SEC). 25,26 Furthermore, liquid chromatography at the critical condition method (LCCC) has been successfully applied for the characterization of cyclic polymers.27-30 Throughout these experimental studies, however, the direct evidence of cyclic structure was not shown, in addition to the fact that the purity of the cyclic molecules has not been determined quantitatively in most of the works. Only for the low molecular weight cyclic polymers, the detailed cyclic structures were directly confirmed by NMR analysis of linking points, 22,23 pyrolysis-gas chromatography/mass spectrometry (Py-GC/MS), 31 and matri...

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Section: Methodsmentioning

confidence: 99%

“…The detailed synthetic procedure of I was followed by the same manners as reported by Hayashi et al, 36 and the purification of I was in the same ways as reported previously. 31,35,37 …”

Section: Methodsmentioning

confidence: 99%

Section: Preparation Of Cyclic Polystyrenesmentioning

confidence: 99%

Section: Molecular Characterizationmentioning

confidence: 99%

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Preparation and Characterization of Cyclic Polystyrenes

Cho

Masuoka

Koguchi

et al. 2005

Polym J

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“…Isoprene copolymers were previously obtained with anionic,4–13 cationic,14, 15 coordination,16, 17 and radical polymerization3, 4, 18, 19 techniques. Such copolymers are interesting because they can be used for rubber production, as effective compatibilizers for natural rubber/acrylic polymer blends,3, 19 and as potential materials for medical applications 20, 21…”

Section: Introductionmentioning

confidence: 99%

Synthesis of polyisoprene–poly(methyl methacrylate) block copolymers via a two‐electron‐transfer mechanism

Janeczek

2005

J. Polym. Sci. A Polym. Chem.

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Supramolecular complexes of alkali metals were used as catalysts in the polymerization of isoprene via a two‐electron‐transfer mechanism. The obtained polyisoprene, having a living end group, was subsequently used to initiate methyl methacrylate polymerization in tetrahydrofuran. Polyisoprene–poly(methyl methacrylate) block copolymers were obtained, and their structure was established with 1H NMR, gel permeation chromatography, differential scanning calorimetry, and experiments of selective extraction. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 1086–1092, 2006

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Telechelic Polymers

Pröll

Nuyken

2018

Encyclopedia of Polymer Science and Technology

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This article presents commonly used synthetic routes and strategies toward polymers or oligomers with well‐defined functional end groups, specified as telechelics. It is to mention that mainly literature since 2000 until present has been considered. Telechelic polymers with diverse end groups are available via anionic and cationic polymerization as well as via controlled radical polymerization, including nitroxide‐mediated radical polymerization and atom transfer radical polymerization. Furthermore, metathesis strategies such as ring‐opening metathesis polymerization and acyclic diene metathesis are presented. In addition, selected examples using chain scission to form such well‐defined functionalities are described. Finally, step‐growth polymerization and the synthesis of macromolecular telechelics are outlined.

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Preparation and Morphology of Model Graft Copolymers of the A3B2 Type with Different Graft Junction Points

Cited by 25 publications

References 15 publications

Preparation and Characterization of Cyclic Polystyrenes

Preparation and Characterization of Cyclic Polystyrenes

Synthesis of polyisoprene–poly(methyl methacrylate) block copolymers via a two‐electron‐transfer mechanism

Telechelic Polymers

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