SYNTHESIS OF BRANCHED POLYMERS: AN INTRODUCTION<sup>*</sup>

Quirk, Roderic P.; Lee, Young Joon; Kim, Jungahn

doi:10.1081/mc-100107862

Cited by 7 publications

(2 citation statements)

References 49 publications

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“…5 Branching provides a means to radically alter the architecture and properties of basic linear polymers. [6][7][8][9][10][11][12][13][14] Methods for forming branched polymers can, for example, enable the covalent linkage of immiscible polymers, which can circumvent the macrophase separation that might occur with a traditional blend. 13,15 Beyond this, extensive research on the bulk and solution properties of branched systems has revealed other unique and potentially useful characteristics.…”

Section: Introductionmentioning

confidence: 99%

Poly(ethylene-co-propylene macromonomer)s: Synthesis and Evidence for Starlike Conformations in Dilute Solution

et al. 2008

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By use of two sequential coordination−insertion polymerizations, a series of ethylene-co-propylene-based comb polymers was synthesized. First, poly(ethylene-co-propylene) macromonomers featuring one unsaturated chain end were synthesized using a titanium bis(phenoxyimine) catalyst. The macromonomers were then homopolymerized using a living nickel α-diimine catalyst. The molecular weights and corresponding number of arms for each poly(macromonomer) were determined using size-exclusion chromatography with viscometry detection and universal calibration. Viscosity−molecular weight conformation plots for the poly(macromonomer)s revealed compact solution structures. Furthermore, viscometric radii for each poly(macromonomer) (R v) and corresponding linear macromonomer (R v)a were determined and the ratio (R v)/(R v)a for each pair was compared to those of a variety of polyisoprene-based star polymers with similar functionality. The comparison revealed that despite the obvious comb topology of the poly(macromonomer)s their dilute solution conformations correspond reasonably well to the bona fide polyisoprene stars.

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Section: Introductionmentioning

confidence: 99%

Poly(ethylene-co-propylene macromonomer)s: Synthesis and Evidence for Starlike Conformations in Dilute Solution

et al. 2008

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“…[65][66][67] Some other excellent reviews on the same subject have also recently appeared. 51,[68][69][70][71][72][73][74] Several research groups have widely studied the methodology in which difunctional monomers such as divinylbenzene and ethyleneglycol dimethacrylate are reacted with anionic species present at the initiation or termination stages of living polymerization to synthesize star polymers. [75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90][91][92][93][94] Since well control of such reactions is difficult, the core parts of the resulting star polymers have always some distributions.…”

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confidence: 99%

Precise Synthesis of Regular and Asymmetric Star Polymers and Densely Branched Polymers with Starlike Structures by Means of Living Anionic Polymerization

Hirao

Hayashi

Tokuda

et al. 2002

Polym J

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ABSTRACT:The subject of this review is to present new synthetic methodologies recently developed by us, which are applicable to both regular and asymmetric star polymers with well-defined architectures. The first methodology involves the coupling reaction of a variety of living anionic polymers of styrene, α-methylstyrene, isoprene, tert-butyl methacrylate, and ethylene oxide with novel chain-end-and in-chain-functionalized polymers with a definite number of benzyl halide moieties intentionally designed as polymeric coupling agents. In the second methodology, we propose a new concept based on iterative approach, with which star polymers can be successively and, in principle, unlimitedly synthesized by repeating the iterative reaction sequence. Finally, a convenient synthesis of densely branched polymers with starlike structures is presented by the quantitative coupling reaction of living anionic polymers with reactive benzyl halide-functionalized backbone polymers based on a grafting-onto method.KEY WORDS Star Polymer / Asymmetric Star Polymer / Living Anionic Polymerization / Iterative Methodology / Polymeric Coupling Agent / 1,1-Diphenylethylene Derivative / Star polymers are branched polymers in which more than three linear polymer chains are linked together at one end of each chain by a central core or a single branch. They have physical properties in bulk, melt, and solution quite distinct from linear analogues. For this reason, star polymers have been widely studied from both synthetic and theoretical points of view. [1][2][3][4][5][6][7][8][9] It is of course essential to use star polymers with welldefined structures for evaluating fundamental understanding regarding the effect of chain branching on such physical properties.At the present time, the most successful methodologies for the synthesis well-defined regular star polymers have been developed mainly based on coupling reactions of living anionic polymers of styrene and 1,3-dinene monomers with multifunctional chlorosilane compounds as electrophilic coupling agents. A variety of star polymers with a definite number of three to eighteen arms have been synthesized. [10][11][12][13][14][15][16][17][18][19] Furthermore, the successful syntheses of the 32-, 64-, and even 128-arm star polymers by using specially designed carbosilane dendrimers have been reported so far. 20,21 Currently, great attention has been paid to more complex asymmetric star polymers whose arms differ in molecular weight and chemical composition, since star polymers of this type are expected to exhibit interesting and unique physical performance originated from their † To whom correspondence should be addressed.branched architectures as well as heterophase structures. [22][23][24][25][26][27][28][29][30][31][32][33] Synthesis of asymmetric star polymers is generally more difficult than that of regular star polymers. In the synthesis of regular star polymers, for example, their arms can be simultaneously introduced by one reaction. On the other hand, two or more highyielding reactions...

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Catalyst separation in atom transfer radical polymerization

Shen

Tang

Ding

2004

Progress in Polymer Science

228

191

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SYNTHESIS OF BRANCHED POLYMERS: AN INTRODUCTION^*

Cited by 7 publications

References 49 publications

Poly(ethylene-co-propylene macromonomer)s: Synthesis and Evidence for Starlike Conformations in Dilute Solution

Poly(ethylene-co-propylene macromonomer)s: Synthesis and Evidence for Starlike Conformations in Dilute Solution

Precise Synthesis of Regular and Asymmetric Star Polymers and Densely Branched Polymers with Starlike Structures by Means of Living Anionic Polymerization

Catalyst separation in atom transfer radical polymerization

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SYNTHESIS OF BRANCHED POLYMERS: AN INTRODUCTION*

Cited by 7 publications

References 49 publications

Poly(ethylene-co-propylene macromonomer)s: Synthesis and Evidence for Starlike Conformations in Dilute Solution

Poly(ethylene-co-propylene macromonomer)s: Synthesis and Evidence for Starlike Conformations in Dilute Solution

Precise Synthesis of Regular and Asymmetric Star Polymers and Densely Branched Polymers with Starlike Structures by Means of Living Anionic Polymerization

Catalyst separation in atom transfer radical polymerization

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SYNTHESIS OF BRANCHED POLYMERS: AN INTRODUCTION^*