Nagoya University · 화학
미네토 우치야마 교수의 연구실은 금속을 사용하지 않는 제어형 양이온 중합 기반의 고분자 합성 기법을 핵심으로 하며, 특히 트리플루오로설폰산(TfOH)을 촉매로 사용하는 cationic RAFT 또는 degenerative chain-transfer 중합을 통해 분자량과 분포를 정밀하게 제어하는 데에 전문성을 가진다. 다양한 전자기부 단량체인 바이닐 에테르, p-메톡시스티렌, 페놀기를 갖는 p-하이드록시스티렌 등에서도 높은 제어도를 확보하며, 블록 공중합체 합성과 고도의 입체선택성 제어까지 가능하다. 이는 고성능 고분자 재료의 설계 및 응용에 기여하는 핵심 기술로 평가된다.
표시된 성과는 수집된 데이터 기준으로 산출되며, 일부 차이가 있을 수 있습니다.
A metal-free, cationic, reversible addition-fragmentation chain-transfer (RAFT) polymerization was proposed and realized. A series of thiocarbonylthio compounds were used in the presence of a small amount of triflic acid for isobutyl vinyl ether to give polymers with controlled molecular weight of up to 1×10(5) and narrow molecular-weight distributions (Mw /Mn <1.1). This "living" or controlled cationic polymerization is applicable to various electron-rich monomers including vinyl ethers, p-meth
Cationic degenerative chain-transfer polymerization of vinyl ethers and p-alkoxystyrenes was investigated using a series of thioethers as a reversible chain-transfer agent via the equilibrium between a growing carbocationic species and the resulting sulfonium intermediate in the presence of a small amount of triflic acid (TfOH) as a cationogen. The stable thioether, which was easily prepared from isobutyl vinyl ether (IBVE) and n-butanethiol, efficiently controls the molecular weight of the resu
Phosphates and phosphinates mediate cationic RAFT polymerization of vinyl ethers with a small amount of triflic acid <italic>via</italic> a phosphonium intermediate.
Abstract A metal‐free, cationic, reversible addition–fragmentation chain‐transfer (RAFT) polymerization was proposed and realized. A series of thiocarbonylthio compounds were used in the presence of a small amount of triflic acid for isobutyl vinyl ether to give polymers with controlled molecular weight of up to 1×10 5 and narrow molecular‐weight distributions (M w /M n <1.1). This “living” or controlled cationic polymerization is applicable to various electron‐rich monomers including vinyl e
The simultaneous control of molecular weight and tacticity in cationic polymerization remains challenging. Here, we propose a new approach for stereospecific living cationic polymerization by combining cationic reversible addition-fragmentation chain transfer (RAFT) polymerization with thiocarbonylthio compounds and stereospecific cationic polymerization of bulky vinyl ethers with Lewis acid catalysts. In this combined system, the molecular weight was controlled by the RAFT process between the g
We report a novel method to synthesize degradable poly(vinyl ether)s with cleavable thioacetal bonds periodically arranged in the main chains using controlled cationic copolymerization of vinyl ethers with a 7-membered cyclic thioacetal (7-CTA) via degenerative chain transfer (DT) to the internal thioacetal bonds. The thioacetal bonds, which are introduced into the main chain by cationic ring-opening copolymerization of 7-CTA with vinyl ethers, serve as in-chain dormant species to allow homogene
A combination of hydrogen chloride adduct of isobutyl vinyl ether (IBVE-HCl) and various metal salts (AgOTf, AgPF<sub>6</sub>, AgSbF<sub>6</sub>, NaBArF (BArF: [3,5-(CF<sub>3</sub>)<sub>2</sub>Ph]<sub>4</sub>B)) efficiently generated initiating cationic species with different low, weakly, or non-nucleophilic counteranions (OTf<sup>-</sup>, PF<sub>6</sub><sup>-</sup>, SbF<sub>6</sub><sup>-</sup>, BArF<sup>-</sup>) and induced a cationic reversible-addition-fragmentation chain-transfer (RAFT) or d
Abstract Thiol‐ene cationic and radical reactions were conducted for 1:1 addition between a thiol and vinyl ether, and also for cyclization and step‐growth polymerization between a dithiol and divinyl ether. p ‐Toluenesulfonic acid (PTSA) induced a cationic thiol‐ene reaction to generate a thioacetal in high yield, whereas 2,2′‐azobisisobutyronitrile resulted in a radical thiol‐ene reaction to give a thioether, also in high yield. The cationic and radical addition reactions between a dithiol and
Core cross-linked star polymers were synthesized<italic>via</italic>cationic RAFT polymerization and three different approaches in combination with a radical RAFT mechanism.
Benzofuran (BzF) is a prochiral, 1,2-disubstituted, unsymmetric cyclic olefin that can afford optically active polymers by asymmetric polymerization, unlike common acyclic vinyl monomers. Although asymmetric cationic polymerization of BzF was reported by Natta et al. in the 1960s, the polymer structure has not been clarified, and there are no reports on molecular weight control. Herein, we report dual control of the optical activity and molecular weight of poly(BzF) using thioether-based reversi
Abstract We report a novel method for synthesizing degradable polymers based on 1,5-shift radical isomerization polymerizations of vinyl ethers with transferable atoms or groups and in-between acid-cleavable ether linkages in the side chains. In particular, vinyl ethers with side chains composed of thiocyano and p -methoxybenzyl ether groups underwent radical isomerization polymerizations via 1,5-shifts, in which a vinyl ether radical abstracted the cyano group intramolecularly to generate a thi
Cationic reversible addition fragmentation chain transfer (RAFT) or DT polymerization is achievable using a series of reversible chain transfer agents, such as thiocarbonylthio compounds, thioethers, and phosphorous esters, in the presence of a small amount of strong protonic acids, such as trifluoromethanesulfonic acid. The protonic acid generates a cationic propagating species, while the chain transfer agent results in stable sulfonium and phosphonium intermediates via the degenerative chain t
