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Facile synthesis of gradient copolymers enabled by droplet-flow photo-controlled reversible deactivation radical polymerization

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Science China Chemistry 2021年第5期64卷 844-851页

作者： Yang Zhou Shantao Han Yu Gu Mao Chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

Monomer sequence influences the properties and applications of ***,massive efforts have been made to implement sequence control of *** this work,we developed a computer-aided droplet-flow polymerization based on photo-controlled reversible-deactivation radical polymerization(photo-RDRP),enabling synthesis of gradient copolymers of tunable sequential arrangements,low dispersity and good structural fidelity from various monomers without following their intrinsic reactivities,which is a key limitation in sequence *** obtained gradient copolymers exhibit unique thermal properties and stimulus responsiveness comparing with the random and block counterparts,and their glass transition behaviour could be regulated by the gradient *** believe that the unprecedented gradient photo-RDRP based on flow synthesis opens a robust and versatile avenue to streamline the synthesis of well-defined gradient polymers,and is compatible with other polymerization mechanisms.

关键词： controlled radical polymerization photopolymerization gradient copolymer flow chemistry sequence control

THE EFFECTS OF MONOMER STRUCTURE OF CYCLIC KETENE ACETALS ON THE BEHAVIOR OF controlled radical RING-OPENING polymerization

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Chinese Journal of Polymer Science 2002年第1期20卷 9-14页

作者：袁金颖 Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026 China Department of Polymer Science and Engineering Peking University Beijing 100871 China

polymerization of three cyclic ketene acetals: i.e., 5,6-benzo-2-methylene-1,3-dioxepane (BMDO), 2-methylene-4phenyl-1,3-dioxolane (MPDO) and 4,7-dimethyl-2-methylene-1,3-dioxepane (DMMDO) were carried out in the presence of ethyl alpha -bromobutyrate/CuBr/2,2'-bipyridine respectively. The structures of poly(BMDO), poly(MPDO) and poly(DMMDO) were characterized by H-1 and C-13-NMR spectra. The effects of monomer structure on the behavior of atom transfer free radical ring-opening polymerization were investigated and the mechanism of controlled free radical ring-opening polymerization was discussed.

关键词： controlled radical polymerization ring-opening polymerization atom transfer radical polymerization cyclic ketene acetal

Challenges and Recent Developments of Photoflow-Reversible Deactivation radical polymerization(RDRP)

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Chinese Journal of Polymer Science 2021年第9期39卷 1069-1083页

作者： Zhuo-Ran Zhong Yi-Nan Chen Yang Zhou Mao Chen State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200433China

Photo-controlled reversible-deactivation radical polymerizati on(photo-RDRP)has been investigated as a"green"and spatiotem-porally controlling pathway for polymer *** the combination of photo-RDRP and flow chemistry has offered opportunities to increase light intensity and enable uniform light irradiation,problems associated with flow approaches still remain for photoflow-RDRP,which has hindered merging flow polymerization with other cutting-edge ***,we summarize challenges and recent achievements in photoflow-RDRP including the development of(a)droplet/slug-flow to regulate reside nee time distribution,(b)mixing techniques to tailor polymer,(c)polymerization in duced self-assembly,and(d)computer-aided *** hope this work will provide in formative knowledge to people in related fields and stimulate novel ideas to promote polymer synthesis in both academia and industry.

关键词： controlled radical polymerization RDRP Photopolymerization Flow chemistry Flow polymerization

SYNTHESIS OF TRIBLOCK COPOLYMERS OF STYRENE AND ISOPRENE BY A NITROXIDE-MEDIATED LIVING FREE radical polymerization

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Chinese Journal of Polymer Science 2004年第1期22卷 55-61页

作者： P. Najafi Mogaddam A. Entezami Lab. of Polymer Chemistry Faculty of Chemistry Tabriz University Tabriz-IranLab. of Polymer Chemistry Faculty of Chemistry Tabriz University Tabriz-Iran

The controlled free radical polymerization of styrene and isoprene initiated with benzoyl peroxide (BPO) in the presence of 2,2,6,6-tetramethyl piperidine-N-oxyl (TEMPO) at 125 'C were performed. The obtained polyisoprene and polystyrene homopolymers served as macroinitiators for block copolymerization of isoprene and styrene to synthesize poly- (styrene-b-isoprene) and poly(isoprene-b-styrene) diblock copolymers. Diblock copolymers with well-defined structures as well as controlled and narrow molecular weight distribution were obtained from the lower-mass polystyrene and polyisoprene homopolymers. These copolymers were found to be active as macroinitiators in the synthesis of the poly(styrene-b-isoprene-b-styrene) and poly(isoprene-b-styrene-b-isoprene) triblock copolymers. 1H-NMR spectroscopy and gel permeation chromatography (GPC) were used for the investigation of polymer structure, molecular weight and polydispersity (PD).

关键词： Diblock and triblock copolymer controlled radical polymerization TEMPO Polystyrene Polyisoprene

SYNTHESIS AND CHARACTERIZATION OF WELL-DEFINED BLOCK COPOLYMERS CONTAINING PENDANT,SELF-COMPLEMENTARY QUADRUPLE HYDROGEN BONDING SITES

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Chinese Journal of Polymer Science 2008年第6期26卷 767-774页

作者：唐黎明 Advanced Materials Laboratory Department of Chemical EngineeringTsinghua University

The title block copolymer (defined as PSUEA) containing pendant,self-complementary quadruple hydrogen bonding sites has been prepared successfully by three ***,poly(styrene-b-2-hydroxyethyl acrylate) (defined as PSHEA) was prepared by living radical polymerizing 2-hydroxyethyl acrylate (HEA) initiated by polystyrene (PSt) macro- initiator,which was prepared via nitroxide-mediated polymerization (NMP) *** treated by excessive 3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate (IPDI),...

关键词： Block polymer controlled radical polymerization Nitroxide-mediated polymerization (NMP) Quadruple hydrogen bonding.

controlled radical COpolymerization OF STYRENE AND MALEIC ANHYDRIDE UNDER GAMMA RADIATION IN THE PRESENCE OF BENZYL DITHIOBENZOATE

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Chinese Journal of Polymer Science 2002年第6期20卷 525-530页

作者： De-cheng Wu Ying-fang Zou Cai-yuan Pan Department of Polymer Science and Engineering University of Science and Technology of China, Hefei 230026, China Department of Polymer Science and Engineering University of Science and Technology of China Hefei 230026

The copolymerization of styrene (St) with maleic anhydride (MAh) under gamma radiation at room temperature in the presence of benzyl dithiobenzoate (BDTB) was found to display 'living' nature evidenced by constant concentration of chain radicals during the copolymerization, linear evolution of molecular weights with conversion and narrow molecular weight distribution (M-w/M-n = 1.23-1.35). The compositional analysis and the sequence structural information of the copolymers obtained from DEPT (Distortionless Enhancement by Polarization Transfer) experiments demonstrate that the copolymers obtained also possess strictly alternating structure.

关键词： controlled radical polymerization alternating copolymer maleic anhydride styrene

Photoenzymatic RAFT Emulsion polymerization with Oxygen Tolerance

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Chinese Journal of Polymer Science 2021年第9期39卷 1138-1145页

作者： Ruo-Yu Li Ze-Sheng An State Key Laboratory of Supramolecular Structure and Materials College of ChemistryJilin UniversityChangchun 130012China Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education School of Life SciencesJilin UniversityChangchun 130012China Institute of Nanochemistry and Nanobiology College of Environmental and Chemical EngineeringShanghai UniversityShanghai 200444China

Photoenzymatic reversible addition-fragmenatation chain transfer(RAFT)emulsion polymerization,surfactant-free or ab initio,of various monomers is reported with oxygen *** surfactant-free emulsion polymerizatoin,poly(N,N-dimethylacrylamide)s were used as stabilizer blocks for emulsion polymerization of methyl acrylate,n-butyl acrylate and styrene,producing well-defined amphiphilic block copolymers,including those with an ultrahigh molecular weight,at quantitative *** controlled character of surfactant-free emulsion polymerization was confirmed by kinetic studies,chain extension studies and GPC *** control was demonstrated by light ON/OFF *** ab initio emulsion polymerization of methyl acrylate and methyl methacrylate,low-dispersity hydrophobic polymers were synthesized with predictable molecular *** study extends the monomer scope suitable for photoenzymatic RAFT polymerization from hydrophilic to hydrophobic monomers and demonstrates that oxygen-toleranee can be equally achieved for emulsion polymerization with excellent RAFT control.

关键词： controlled radical polymerization RAFT Emulsion polymerization Oxygen toleranee Photoenzymatic polymerization

Organoboron chemistry towards controlled and precise polymer synthesis

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Science China Chemistry 2023年第12期66卷 3467-3483页

作者： Yuxuan Du Jin Dong Chaoran Xu Xiangcheng Pan State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai 200438China

Organoboron reagents have garnered considerable attention due to their distinct properties. In recent years, boronic acids and boronate esters have been important intermediates for cross-coupling reactions and other functional group construction and are often used to synthesize small organic molecules, drugs, and bioactive substances. In this feature article, we encapsulate the strategy of harnessing the unique properties of organoboron reagents to overcome challenges encountered in conventional polymer synthesis. We delve into the synthesis of boron-containing monomers and polymer materials, unraveling the unique attributes of these newfound polymers while offering innovative insights into their application within recyclable or reprocessable materials. We develop organoboron-based photocatalysts, employing their inner-sphere electron transfer(ISET) mechanisms to initiate controlled radical polymerization. We utilize alkylborane to initiate controlled radical polymerization and further designed B-alkylcatecholboranes to prepare ultra-high molecular weight polymers. Notably, we also propose a liquid-phase synthesis method based on organoboron tags and apply it to the precise synthesis of sequence-controlled conjugated *** advancements open up new frontiers in the realm of polymer science, and the versatility and potential of organoboron reagents in polymer synthesis continue to inspire exciting research endeavors.

关键词： organoboron boron-containing polymer controlled radical polymerization polymer synthesis