| POLYMERS Vol.62 No.5 |
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COVER STORY
Precision Polymerization:Development and Practical Application |
| COVER STORY: Highlight Reviews |
| FI Catalysts: New Olefin Polymerization Catalysts for the Creation of Value-Added Olefin-Based Materials | Makoto MITANI, Terunori FUJITA |
| <Abstract> This contribution reports on the development and application of FI catalysts for olefin polymerization. Research based on a ligand-oriented catalyst design concept led to the discovery of phenoxy-imine ligated early transition metal catalysts, better known as FI catalysts. FI catalysts exhibit exceptionally high ethylene insertion efficiency (max. TOF 65,000/sec/atm, TON >20,000,000), meaning FI catalysts are the most active of artificial catalysts. Uniquely, FI catalysts are able to synthesize olefin-based materials with precisely controlled structures. Such olefin-based polymers include selective vinyl-terminated PEs, ultra-high molecular weight PEs, and stereo- and regio-irregular poly(higher α-olefin)s. Additionally, FI catalysts produce highly isotactic and syndiotactic PPs and polystyrenes, and polyolefinic block copolymers from ethylene, propylene, and higher α-olefins. Moreover, based on FI catalyst technology, a variety of end-functionalized PEs, PE/polar polymer hybrid materials, and cyclic olefin copolymers with extremely high thermal stability can also be created. Some of these inspiring materials are now beginning to enter the commercial phase. Keywords: Olefin Polymerization / Postmetallocene Catalysts / FI Catalysts / Polyolefins |
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| New Generation Functional Polymers by Living Cationic Polymerization | Sadahito AOSHIMA, Arihiro KANAZAWA |
| <Abstract> Recent advances in the living cationic polymerization are reviewed, especially focusing on the newly developed synthesis of well-controlled functional polymers. The precision synthesis has created new possibilities of thermosensitive polymers exhibiting an upper critical solution temperature-type phase separation in water or various organic solvents. The antibacterial and hemolytic activities were examined using a series of amphiphilic block and random copolymers with amino side groups. In addition to monomer design, a monomer sequence in a copolymer plays a critical role in having a selective antibacterial effect. The controlled alternating copolymerization of vinyl ethers and various aldehydes was also achieved under appropriate reaction conditions, producing copolymers with highly selective acid-degradability. Finally, the recent development of initiating systems for the living cationic polymerization by our group is briefly reviewed. Keywords: Cationic Polymerization / Living Polymerization / Functional Polymer / Stimuli-Responsive Polymer / Thermosensitive Polymer |
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| Precision Synthesis of π-Conjugated Polymers by Catalyst-Transfer Condensation Polymerization | Masataka NOJIMA, Yoshihiro OHTA, Tsutomu YOKOZAWA |
| <Abstract> π-Conjugated polymers are an important class of materials, but it was difficult to control the molecular weight and the polymer end groups because of the production via step-growth polycondensation. In this highlight review, we describe development and generality of catalyst-transfer condensation polymerization (CTCP) that proceeds in a chain-growth polymerization manner and has made it possible to synthesize well-defined π-conjugated polymers in a similar way like living polymerization. Keywords: π-Conjugated Polymer / Catalyst-Transfer Condensation Polymerization |
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| COVER STORY: Topics and Products |
| Living Anionic Polymerization of Novel Hydrocarbon Monomers | Takashi ISHIZONE |
| <Abstract> Anionic polymerizations of a series of hydrocarbon monomers were investigated to confirm their polymerizability. Anionic polymerization of 1,4-divinylbenzene proceeded with organolithium initiator in the presence of potassium tert-butoxide in THF to give a soluble polymer with predicted molecular weight and very narrow molecular weight distribution (Mw/Mn < 1.1). A serious side reaction such as cross-linking was sufficiently suppressed by the effect of added salts. Living anionic polymerizations of 4-(1-adamantyl)styrene and 2-(1-adamantyl)-1,3-butadiene were realized to afford well-defined polymers showing high glass transition temperatures at 234 and 106 ℃, indicating the effect of introduced adamantyl group on thermal property. Exomethylene hydrocarbon monomers such as α-methyleneindane, α-methylenetetralin, and benzofulvene (α-methyleneindene) smoothly underwent the anionic polymerizations with organolithium and organopotassium initiators to form tailored polymers. The anionic polymerizations of benzofulvene gave a polymer containing 1,2-and 1,4-addition modes and could be initiated with low nucleophilic initiators such as Grignard reagent, alkoxide, and living poly(alkyl methacrylate), indicating the extremely high anionic polymerizability. Keywords: Living Polymer / Anionic Polymerization / Hydrocarbon Monomers / 1,4-Divinylbenzene / 4-(1-Adamantyl)styrene / 2-(1-Adamantyl)-1,3-butadiene / α-Methyleneindane / Benzofulvene |
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| Precise Synthesis of Functional Polymers by Living Radical Polymerization of S-Vinyl Monomers | Hideharu MORI |
| <Abstract> Recent significant progress of controlled radical polymerization has allowed for the synthesis of well-defined functional polymers by radical polymerization of non-conjugated monomers. We recently developed the controlled synthesis of sulfur-containing polymers by reversible addition-fragmentation chain transfer (RAFT) polymerization of non-conjugated S-vinyl monomers. Differing from styrene, (meth)acrylate, and (meth)acrylamide-type monomers, the direct linkage of the sulfur atom to the vinyl group is an important feature of these monomers, because it may affect not only the polymerization behavior but also various properties of the resulting polymers. Sulfonic acid-containing polymers and thermoresponsive-ionic block copolymers were obtained by RAFT polymerization of vinyl sulfonate esters using a suitable xanthate-type chain transfer agent, followed by deprotection. RAFT polymerization of S-vinyl sulfide derivatives having aromatic rings were found to proceed in controlled fashions. Incorporation of optoelectronic groups on the halogen moiety of the polymers derived from S-vinyl sulfides with halophenyl groups afforded novel functional polymers with characteristic properties. Keywords: RAFT Polymerization / S-Vinyl Monomer / Sulfur-Containing Polymer / Non-Conjugated Monomer / Block Copolymer / Xantate-Type Chain Transfer Agent |
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| Polyisobutylene Based Polymers by Living Cationic Polymerization: Research, Development and Industrialization | Yoshimichi YAMANAKA, Katsuhiko KIMURA |
| <Abstract> Kaneka has led in the industrialization of living cationic polymerization. Kaneka started running the first industrial process using living cationic polymerization for the production of isobutylene in 1997. The technology of block copolymerization of isobutylene and styrene in living fashion has also been developed at our company. Our current products are the telechelic oligomers “EPION®” and the thermoplastic elastomers “SIBSTAR®”. This report traces the history of the development of the living polymerization technology at Kaneka. Keywords: Living Cationic Polymerization |
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| Directed Self Assembly Technology with the Polymers Prepared by Living-Anionic Polymerization for Fabrications of Finer Patterns | Yoshikazu YAMAGUCHI |
| <Abstract> Demand for high performance chips has drastically increased due to the development of smart phones, tablet-PCs and so on. Most “State of the art” Fabs have implemented ArF immersion technology today. Double patterning, double exposure, and side-wall image transfer technology allow for the extension of ArF immersion into 2x nm half-pitch (hp) application. In order to fabricate finer patterns, it is necessary to develop new processes, such as EUV, EB, Nano imprint and Directed Self Assembly (DSA). It is possible to fabricate patterns with less than 20 nmhp by combining DSA and the other technologies. In this paper, the application of DSA for semiconductor manufacturing is introduced. 8 nmhp line and space (L/S) pattern and 15 nm hole pattern are obtained with a block copolymer system and 19 nm L/S pattern was obtained with a blending polymer system. These results have promising potentials for the fabrications of finer patterns. Keywords: Directed Self Assembly / DSA / Semiconductor / Lithography / Block-Copolymer / Blending / χ-Parameter |
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| Development and Industrialization of Nitroxide Based Living Polymerization | Fumi ARIURA |
| <Abstract> Over a span of 20 years, Arkema has developed nitroxide based controlled radical polymerization (CRP) technology. The principal motivation was to develop a CRP catalyst which can be applied to industrial polymer production. After lots of studies, we discovered an alkoxyamine consisting of stable nitroxide, which is called BlocBuilder® MA. Arkema has also developed other ranges of CRP products based on BlocBuilder® MA. Nanostrength® is triblock block copolymer, PMMA-b-PBA-b-PMMA. It is known as a high performance impact modifier of epoxy resin. Flexibloc® is a living polymer which can be reactivated in the polymerization from its chain end. It allows users to synthesize CRP polymers without special treatment such as removal of residual monomer. On the other hand, Arkema’s subsidiary company, Altuglas® International had successfully proven the further possibility of CRP technology. PMMA cast sheet modified BlocBuilder® MA based elastomer showed well-organized nanostructure in the bulk. This cast sheet shows higher impact resistance, good transparency and remarkable chemical resistance. Keywords: CRP / Nitorixide / Polymer Design / Industrialization / Block Copolymer / Living Polymer / Nanostructure |
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| Polymer Science and I: A Personal Account |
| Explore Chemistry！ | Kenta KOKADO |
| <Abstract> “Enjoy Chemistry!” is the slogan of my supervisor, Prof. Chujo. This personal account traces my exploration of chemistry, toward the world of “enjoy chemistry”. |
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| Front-Line Polymer Science |
| Cutting-Edge in Precision Radical Polymerization: Advanced Reaction Control and Functional Macromolecular Chains | Makoto OUCHI, Takaya TERASHIMA, Mitsuo SAWAMOTO |
| <Abstract> This short account focuses on some cutting-edge topics and develpoments in metal-mediated precision/living radical polymerization, apart from the basic reaction design such as catalyts. Specifically, following a brief review on catalyst design for element strategy and sustainability, discussion is directed to: strategies for precision sequence control in synthetic (carbon-chain based) macromolecules; tandem catalysis in copolymerization towards one-pot gradient copolymers; and core-functionalized star polymers for nano-reaction space and host-guest recognition. The article’s messages include that living radical polymerization has now led to the preparation of well-defined macromolecules within the reach of researchers beyond polymer chemistry; and that we may now achieve precise structural control and advanced functions as seen in nature, such as DNA, peptide, and enzyme. Keywords: Living Radical Polymerization / Catalyst / Element Strategy / Sequence / Template / Tandem Catalysis / Gradient Copolymer / Star Polymer |
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