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51.
Shinya Hamasaki Chie Sawauchi Masami Kamigaito Mitsuo Sawamoto 《Journal of polymer science. Part A, Polymer chemistry》2002,40(4):617-623
A fast living radical polymerization of methyl methacrylate (MMA) proceeded with the (MMA)2? Cl/Ru(Ind)Cl(PPh3)2 initiating system in the presence of n‐Bu2NH as an additive [where (MMA)2? Cl is dimethyl 2‐chloro‐2,4,4‐trimethyl glutarate]. The polymerization reached 94% conversion in 5 h to give polymers with controlled number‐average molecular weights (Mn's) in direct proportion to the monomer conversion and narrow molecular weight distributions [MWDs; weight‐average molecular weight/number‐average molecular weight (Mw/Mn) ≤ 1.2]. A poly(methyl methacrylate) with a high molecular weight (Mn ~ 105) and narrow MWD (Mw/Mn ≤ 1.2) was obtained with the system within 10 h. A similarly fast but slightly slower living radical polymerization was possible with n‐Bu3N, whereas n‐BuNH2 resulted in a very fast (93% conversion in 2.5 h) and uncontrolled polymerization. These added amines increased the catalytic activity through some interaction such as coordination to the ruthenium center. © 2002 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 40: 617–623, 2002; DOI 10.1002/pola.10148 相似文献
52.
Kazuaki Miyashita Masami Kamigaito Mitsuo Sawamoto Toshinobu Higashimura 《Journal of polymer science. Part A, Polymer chemistry》1994,32(13):2531-2542
The end-functionalization of living polymers with bases (methanol, benzylamine, diethyl sodiomalonate, and sodium methoxide) and organosilicon compounds [X ? Si(CH3)3;X ? : CH2?C(CH3)COO? , CH3COO? , CH2?CHCH2? , C6H5? ] was investigated in the living cationic polymerization of styrene initiated with the 1-phenylethyl chloride/SnCl4/nBu4NCl system in CH2Cl2 at ?15°C. The four bases and C6H5SiMe3, independent of their structures, were apparently incapable of reacting with the living end and invariably led to polystyrenes with the ω-end chlorine [~ ~ ~ CH2CH(Ph)Cl] originated from the initiating system. The number-average end-functionality (F?n) of the chloride, determined by 1H-NMR, was close to unity (F?n > 0.9). The presence of chlorine in the polymer was also confirmed by elemental analysis. In contrast, the quenching by the trimethylsilyl compounds with X = methacryloxy, acetoxy, and allyl gave ω-end-functionalized polystyrenes with the corresponding terminal groups (X) for which the F?n values were close to unity (F?n > 0.9). The effects of the structure of silyl compounds on end-capping are also discussed. © 1994 John Wiley & Sons, Inc. 相似文献
53.
SAWAMOTO Mitsuo 《中国科学:化学(英文版)》2012,55(5):647-647
It is a great pleasure for international colleagues in polymer science to celebrate Professor Fosong Wang on his 80th birthday. Professor Fosong Wang, a member of the Chinese Academy of Sciences, is a great polymer scientist, with over 300 publications and a few books. He is internationally recognized in his work on stereoregular polymers and electronically active polymers, particularly the development of 相似文献
54.
The paper concerns characterization of BMO in terms of Banach function spaces. In particular, we are interested in characterizing BMO by using the variable Lebesgue norm. 相似文献
55.
Makoto Obata Ryo Asato Kazunori Mitsuo Shiho Hirohara 《Journal of polymer science. Part A, Polymer chemistry》2014,52(7):963-972
Three CF3‐substituted methyl methacrylates (MMAs), 2,2,2‐trifluoroethyl methacrylate (TFEMA), 1,1,1,3,3,3‐hexafluoroisopropyl methacrylate (HFIPMA) and nonafluoro‐tert‐butyl methacrylate (NFTBMA), were polymerized by conventional radical polymerization to give oxygen‐permeable polymers for application in pressure‐sensitive paint (PSP). The radical copolymerizations of styrene with TFEMA, HFIPMA, or NFTBMA were carried out to examine the effect of CF3 groups on the polymerizability. The e values increased in the order of MMA (0.40) < TFEMA (0.76) < HFIPMA (1.19) < NFTBMA (1.31). The homopolymers of TFEMA, HFIPMA and NFTBMA (PTFEMA, PHFIPMA, and PNFTBM, respectively) were examined as polymers for use in PSP using 5,10,15,20‐tetrakis(pentafluorophenyl)porphinato platinum(II) (PtTFPP). The PSP consisting of PNFTBMA and PtTFPP exerted very high pressure sensitivity and very low temperature sensitivity. In the absence of oxygen, the temperature sensitivity decreased in the order of PTFEMA > PHFIPMA > PNFTBMA = PMMA, which corresponds to the order of glass transition temperatures (Tg). However, the activation energies of the overall process of the luminescence quenching by oxygen were found to be 16.8 (PMMA), 13.0 (PTFEMA), 6.8 (PHFIPMA), and 4.3 kJ mol?1 (PNFTBMA). Therefore, the low temperature sensitivity of PNFTBMA was attributed to its high degree of substitution with CF3 groups and to its relatively high Tg value. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 963–972 相似文献
56.
Naomichi Furukawa Mitsuo Fukumura Takehiko Nishio Shigeru Oae 《Phosphorus, sulfur, and silicon and the related elements》2013,188(2):231-237
Abstract Various N-acyldiphenylsulfilimines (1a-k) were found to undergo photolysis in argon atmosphere, to afford the corresponding isocyanates, diphenyl sulfide and diphenyl disulfide. Attempts to trap intramolecularly the acylnitrene with olefinic linkage or sulfide afforded small amounts of the trapped products, whereas photolysis of N-mesitoyldiphenyl-sulfilimine (Ia) afforded a C–H inserted product of the nitrene in a substantial yield together with the isocyanate. Benzophenone-sensitized photolysis of Ia indicates that the nitrene generated is a singlet species. 相似文献
57.
Kanako Sekimoto Mitsuo Takayama 《Journal of the American Society for Mass Spectrometry》2013,24(5):780-788
Collision-induced dissociation (CID) experiments were performed on atmospheric ion adducts [M + R]– formed between various types of organic compounds M and atmospheric negative ions R- [such as O2 –, HCO3 –, COO–(COOH), NO2 –, NO3 –, and NO3 –(HNO3)] in negative-ion mode atmospheric pressure corona discharge ionization (APCDI) mass spectrometry. All of the [M + R]– adducts were fragmented to form deprotonated analytes [M – H]– and/or atmospheric ions R–, whose intensities in the CID spectra were dependent on the proton affinities of the [M – H]– and R– fragments. Precursor ions [M + R]– for which R- have higher proton affinities than [M – H]– formed [M – H]– as the dominant product. Furthermore, the CID of the adducts with HCO3 – and NO3 -(HNO3) led to other product ions such as [M + HO]– and NO3 –, respectively. The fragmentation behavior of [M + R]– for each R– observed was independent of analyte type (e.g., whether the analyte was aliphatic or aromatic, or possessed certain functional groups). 相似文献
58.
Abstract Many polysaccharides are expected to apply as biomaterials because they generally show good biocompatibilities and biodegradabilities. It has recently been reported that the saccharides play important roles in biological recognition and the transmission of biological information on a cellar surface. Galactomannan (GalM) is a polysaccharide whose main chain is composed of β-1,4-linked mannose units only. It has some branching α-galactose residues at the C-6 position of mannose units. Therefore, it was of interest of us to use GalM as a drug carrier which was targeted to hepatocyte having a galactose receptor on its cellar surface. Dicarboxy-galactomannan (DC-GalM), which has reactive functional groups and is a carboxylic acid derivative of galactomannan, was prepared by IO4-/CIO2- oxidation of GalM. The obtained DC-GalM showed specific binding with maclura pomifera (MPA) [1] which has a specificity to α-galactose. Moreover, DC-GalM showed selective incorporation into hepatocyte. Adriamycine (ADR), which is one of the most prominent anticancer agents, was immobilized to DC-GalM. The DC-GalM/ADR conjugate showed specific cytotoxic activity against HepG2 human hepatoma cells which have a galactose receptor on the cell surface, compared with Hela utrocervical carcinoma cells which have no galactose receptor. 相似文献
59.
60.
Xiaolei Wang Miho Emoto Atsushi Sugimoto Yusuke Miyake Kaori Itto Mitsuo Amasaka Shu Xu Hiroshi Hirata Hirotada Fujii Hirokazu Arimoto 《Tetrahedron letters》2014
A scalable synthetic route for 15N-labeled 4-oxo-2,2,6,6-tetraethylpiperidine nitroxide (15N-TEEPONE) is described. This 15N-labeled nitroxide is suitable for electron paramagnetic resonance imaging of brain, and its higher sensitivity compared with that of its 14N-counterpart is an important advantage of the labeled derivative. 相似文献