Recent Progress on Synthesis of Hyperbranched Polymers with Controlled Molecular Weight Distribution

Shi, Yi; Graff, Robert W.; Gao, Haifeng

doi:10.1021/bk-2015-1188.ch010

Cited by 8 publications

(5 citation statements)

References 51 publications

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“…Hyperbranched polymers, as an important category of soft nanomaterials, have received considerable interest and found various applications in catalysis, biomaterials, microelectronics, and nanomedicines, due to their three-dimensional structure, cavernous interior, and large number of peripheral functionalities. − In comparison to dendrimers that require tedious multistep synthesis and inefficient chromatographic purification, hyperbranched polymers are generally prepared in an effortless one-pot polymerization of AB m ( m ≥ 2) monomer − or AB* inimer (containing initiator fragment B* and monomer vinyl group A in one molecule). − However, the random bimolecular (e.g., monomer–monomer, polymer–polymer, and monomer–polymer) reactions in these one-pot synthesis significantly compromise the structural control of hyperbranched polymers and result in polymer product with extremely high polydispersity, which undermines the physical properties of hyperbranched polymers. − …”

Section: Introductionmentioning

confidence: 99%

Design a Highly Reactive Trifunctional Core Molecule To Obtain Hyperbranched Polymers with over a Million Molecular Weight in One-Pot Click Polymerization

et al. 2016

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We present the first one-pot one-batch synthesis of hyperbranched polymers with over a million molecular weight and low polydispersity in the coppercatalyzed alkyne−azide cycloaddition (CuAAC) polymerization of AB 2 monomer. In contrast to the traditional triazido core molecule that failed to produce high molecular weight polymer, a novel tris-triazoleamine-based B 3 molecule was designed, which complexed with Cu I catalyst and activated the azido reactivity in both B 3 and B 3 -containing polymers. The polymerization demonstrated linear increase of polymer molecular weights with the feed ratio of [AB 2 ] 0 :[B 3 ] 0 with no need of slow monomer addition. At the same time, a higher ratio of [Cu I ] 0 :[B 3 ] 0 showed no influence on molecular weight but significantly increased the polymerization rate and produced hyperbranched polymers with higher degree of branching. The one-pot polymerization using [AB 2 ] 0 :[B 3 ] 0 :[Cu] 0 = 2700:1:10 produced hyperbranched polymers with molecular weight M n = 1.01 × 10 6 and polydispersity M w /M n = 1.05 in 4 h.

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Section: Introductionmentioning

confidence: 99%

Design a Highly Reactive Trifunctional Core Molecule To Obtain Hyperbranched Polymers with over a Million Molecular Weight in One-Pot Click Polymerization

et al. 2016

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“…Meanwhile, our group has recently demonstrated a formulation method to regulate the structure of hyperbranched polymers in a heterogeneous biphasic medium, which efficiently segregated the random bimolecular reactions into each confined micellar space. [37][38][39] In a parallel effort, several research groups are also interested in manipulating the DB value of hyperbranched polymers by tuning the reactivity of the multiple B groups in the consecutive reactions of AB 2 monomers 40 or postmodification of synthesized hyperbranched polymers. 41 The first idea is facile and has been explored in acid-catalyzed Friedel-Crafts hydroxyalkylation reactions, 42 catalysttransfer Suzuki-Miyaura reactions, 43 and thiol-yne reactions.…”

Section: Equationmentioning

confidence: 99%

A Novel Chain-Growth CuAAC Polymerization: One-pot Synthesis of Dendritic Hyperbranched Polymers with Well-Defined Structures

Cao

Shi

Gao

2016

Synlett

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This highlight presents an overview of our recent achievements on developing a chain-growth copper-catalyzed azide-alkyne cycloaddition (CuAAC) polymerization of multifunctional AB m (m ≥ 2) monomers to produce structurally defined hyperbranched polymers in one pot. The chain-growth mechanism is attributed to the dedicate complexation between copper(I) catalyst and triazole groups that confine the copper catalyst in the polymers and selectively favor the polymer-monomer reaction rather than the monomer-monomer reactions. The living nature of this CuAAC polymerization was extensively explored to demonstrate the intriguing features of multibatch addition of various AB 2 monomers to produce hyperbranched polymers with high molar mass, low dispersity, core-shell segmented structures, and tunable solubility. 1 Background 2 Development of Living Chain-Growth CuAAC Polymerization 3 Functionalization and Segmented Structure in Hyperbranched Polymers 4 Conclusion Key words CuAAC click reactions, hyperbranched polymers, chaingrowth polymerization, high degree of branching, narrow molar-mass distribution BackgroundHyperbranched polymers, as an important category of soft nanomaterials, are often considered analogues of dendrimers due to their similar three-dimensional arborescent structures, high density of dendritic structural units, and multiple periphery groups. [1][2][3] These structural characteristics not only endow the polymers various intriguing physical properties, such as high shear resistance, low viscosity in the states of melt and solution, but also find them a variety of applications ranging from lubricant additives to catalysts and nanomedicines. 4Xiaosong Cao (left) obtained his BSc and MSc degrees at Wuhan University. In 2013, he joined the research group of Prof. Gao to pursue his PhD in organic chemistry at the University of Notre Dame. His research focuses on new polymerization methodology, synthesis of topological polymers with precise structure, and the relationship study between structure and properties in polymers. Dr. Yi Shi (right) obtained his BSc and MSc degrees at Xiangtan University and his PhD at Institute of Chemistry, Chinese Academy of Sciences (ICCAS) in 2013. After his graduation, he joined Prof. Gao's group in the Department of Chemistry and Biochemistry at the University of Notre Dame as a postdoctoral research associate. His research at Notre Dame is developing a new method that can achieve one-pot synthesis of hyperbranched polymers with high molar masses, low dispersity, and segmented dendritic structures as well as their potential applications. Dr. Haifeng Gao (middle) obtained his BSc and MSc degrees at Fudan University in China and his PhD at Carnegie Mellon University in 2008. After two years of postdoctoral experience at the University of California Berkeley, Dr. Gao started his independent career in 2011 at the University of Notre Dame, where he is currently an Assistant Professor in the Department of Chemistry and Biochemistry. Dr. Gao's research focuses on the design and synth...

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“…29 Branched polymers with narrow molecular weight distributions (MWDs) can also be synthesized by this method. 30 Another interesting synthetic approach is the (co)polymerization of di-or multifunctional monomers (crosslinkers) in the presence of chain transfer agents (CTAs). This strategy has been known for a relatively long time, 31,32 and its utility has become increasingly appreciated since the work of Sherrington and collaborators.…”

Section: Introductionmentioning

confidence: 99%

“…The method is often carried out under controlled/"living" polymerization conditions, such as reversible deactivation radical polymerization, 21–23 living ionic polymerization, 24–27 ring‐opening metathesis polymerization, 28 or group transfer polymerization 29 . Branched polymers with narrow molecular weight distributions (MWDs) can also be synthesized by this method 30 . Another interesting synthetic approach is the (co)polymerization of di‐ or multifunctional monomers (crosslinkers) in the presence of chain transfer agents (CTAs).…”

Section: Introductionmentioning

confidence: 99%

Hypervalent iodine‐based initiators and efficient chain transfer agents for the synthesis of branched polymers from crosslinkers

Kumar

Sayala

Tang

et al. 2022

Polymer International

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The synthesis of hyperbranched polymers with alkyl chloride-type chain ends was accomplished by the copolymerization of methyl methacrylate and a crosslinker, ethylene glycol dimethacrylate, in the presence of 1-chloro-1,2-benziodoxol-3(1H)one (BIO-Cl), which served as both a radical initiator and an efficient chain transfer agent. The polymerizations were carried out under thermal (80 °C) and photochemical (irradiation with visible light) conditions. As a result of the transfer of Cl atoms from BIO-Cl to the propagating radicals, gelation was delayed to high monomer conversions and, until that point, soluble branched polymers were formed. Even pure crosslinker could be polymerized to moderate conversions (>15%, depending on the amount of added BIO-Cl), yielding branched polymers prior to formation of networks. The effect of the concentrations of crosslinker and hypervalent iodine(III) compound on the outcome of the (co)polymerizations as well as the kinetic features of Cl transfer and decomposition of BIO-Cl were studied in detail.

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Recent Progress on Synthesis of Hyperbranched Polymers with Controlled Molecular Weight Distribution

Cited by 8 publications

References 51 publications

Design a Highly Reactive Trifunctional Core Molecule To Obtain Hyperbranched Polymers with over a Million Molecular Weight in One-Pot Click Polymerization

Design a Highly Reactive Trifunctional Core Molecule To Obtain Hyperbranched Polymers with over a Million Molecular Weight in One-Pot Click Polymerization

A Novel Chain-Growth CuAAC Polymerization: One-pot Synthesis of Dendritic Hyperbranched Polymers with Well-Defined Structures

Hypervalent iodine‐based initiators and efficient chain transfer agents for the synthesis of branched polymers from crosslinkers

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