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1.
Koji Ishizu Satoru Minematsu Takashi Fukutomi 《Journal of polymer science. Part A, Polymer chemistry》1990,28(5):1091-1099
We have studied the structural changes on poly(2-hydroxyethyl methacrylate) (PHEMA)/polystyrene (PS) blends by means of phase growth of microheterophase pattern on a template surface composed of poly[2-hydroxyethyl methacrylate (HEMA)-g-styrene (S)] graft copolymer (lamellar shape). The PS macromonomer was synthesized by free radical polymerization of S monomer initiated by a functional initiator [2,2'-azobis(2-(2-imidazolin-2-yl)propane: VA-061] in the presence of a degradative chain transfer agent, followed by an end-capping reaction with p-chloromethylstyrene (CMS). Poly(HEMA-g-S) graft copolymers were prepared by free radical copolymerization of these vinylbenzyl-terminated PS macromonomers with HEMA comonomer. 相似文献
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Junko Fukutomi Yuko Adachi Akari Kaneko Atsuomi Kimura Hideaki Fujiwara 《Journal of inclusion phenomena and macrocyclic chemistry》2007,58(1-2):115-122
The inclusion complex formation of 4-sulfothiacalix[4]arene sodium salt (STCAS) and Xe has been investigated by using hyperpolarized
129Xe NMR spectroscopy. Our new continuous-flow type hyperpolarizing system has advantageous capabilities that can supply hyperpolarized
gases continuously and directly to a sample solution in a NMR tube. Consequently saturated Xe concentration in the aqueous
solution of STCAS is maintained during the NMR experiment, and 129Xe NMR spectra can be obtained in remarkably short time. STCAS concentration dependence of 129Xe chemical shift has been analyzed in an elaborated way by a computer method as well as a simple graphic method that we have
proposed. The association constant K:13.6±0.8 M−1 at 25 °C was obtained, and further analysis of the temperature dependence has successfully given thermodynamic parameters
of enthalpy (ΔH) and entropy (ΔS) for the inclusion complex formation: ΔH = −11.9±1.9 kJ mol−1 and ΔS = −17.4±5.8 JK−1 mol−1. The energetic aspects of complex formation are discussed from the size effect and from the molecular theory of standard
entropy, and a release of definite number of water molecules from STCAS cavity is suggested in the inclusion complex formation
with Xe. 相似文献
3.
The anisotropy factor g, one of the optical properties of biological tissues, has a strong influence on the calculation of the scattering coefficient μ s in inverse Monte Carlo (iMC) simulations. It has been reported that g has the wavelength and absorption dependence; however, few attempts have been made to calculate μ s using g values by taking the wavelength and absorption dependence into account. In this study, the angular distributions of scattered light for biological tissue phantoms containing hemoglobin as a light absorber were measured by a goniometric optical setup at strongly (405 nm) and weakly (664 nm) absorbing wavelengths to obtain g. Subsequently, the optical properties were calculated with the measured values of g by integrating sphere measurements and an iMC simulation, and compared with the results obtained with a conventional g value of 0.9. The μ s values with measured g were overestimated at the strongly absorbing wavelength, but underestimated at the weakly absorbing wavelength if 0.9 was used in the iMC simulation. 相似文献
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Mitsutoshi Fukuda Makoto Fukutomi Yoshio Kato Tsutomu Hashimoto 《Journal of Polymer Science.Polymer Physics》1974,12(5):871-890
A series of polystyrenes with weight-average molecular weight M?w up to 1.3 × 107 was prepared by anionic polymerization in tetrahydrofuran (THF). Each sample was characterized by gel-permeation chromatography, light scattering, and viscometry. It was found that each sample had an almost symmetrical and very narrow molecular weight distribution (M?w/M?n < 1.07). The mean-square unperturbed radius of gyration 〈S2〉0 was determined in trans-decalin at 20.4°C as 〈S2〉0 = 7.86 × 10?18M?w (cm2). The particle scattering factor was well represented by the Debye equation irrespective of solvent in the range of M?w < 4 × 106, and only a small deviation was observed in benzene at higher molecular weights. The penetration function Ψ ≡ A2M2/4π3/2NA〈S〉23/2 was found to approach a relatively low asymptotic value of 0.21–0.23 at molecular weights above 2 × 106 in benzene at 30°C, where A2 is the second virial coefficient and NA is Avogrado's number. It was also found that the theta temperature in trans-decalin was affected by the nature of polymer samples. A difference of about 3°C in the theta temperature was observed between two series of anionic polystyrenes, one prepared in THF and the other in benzene, but there was practically no difference in unperturbed chain dimension. 相似文献
7.
Takashi Fukutomi Atsushi Yokota Koji Ishizu 《Journal of polymer science. Part A, Polymer chemistry》1984,22(11):2983-2991
Poly(methyl mehtacrylate)(PMMA) macromers with several vinyl groups at both chain ends were synthesized by the mechanical scission reaction of the main chain in the presence of p-divinylbenzene(p-DVB). The radical copolymerization of this macromer with styrene(St) or MMA was carried out in benzene at 60°C and the reactivity ratio of both monomers (r2) was calculated from a kinetic scheme of copolymerization. As a result, the effect of molecular weight and concentration of macromers was not observed in both copolymerization systems. The value of r2, however, decreased as the number of end vinyl groups in a macromer (N) increased. These results are discussed in some detail as we describe the construction of the kinetic model of copolymerization. 相似文献
8.
Koji Ishizu Katsumi Inagaki Takashi Fukutomi 《Journal of polymer science. Part A, Polymer chemistry》1985,23(4):1099-1108
Well defined AB and BAB type poly[styrene(ST)-b-4-vinylpyridine(4VP)]s were prepared by anionic living polymerization in tetrahydrofuran (THF) at ?78°C. Casting AB and BAB type poly(ST-b-4VP)s with a composition of about 50 mol% PST from 1,1,2-trichloroethane (TCE) produced specimens with lamellar microdomain structures. Quaternization of P4VP and sulfonation of PST domains (lamellar and spherical structures), accompanied by each domain fixing, were carried out under various reaction conditions. The piezodialysis of the prepared charge mosaic membrane with its lamellar microdomain structure was measured from a sodium chloride (NaCl) aqueous solution. The results are discussed in some detail. 相似文献
9.
Koji Ishizu Satoshi Ishikawa Takashi Fukutomi 《Journal of polymer science. Part A, Polymer chemistry》1985,23(2):445-452
Well defined BAB-type poly[styrene(ST)-b-2-methyl-2-oxazoline(MeOz)] was prepared by the cationic polymerization of α,ω-p-toluenesulfonic acid ester-terminated PST (PST-BTs) as an initiator. Alkaline hydrolysis of this block copolymer was carried out under various reaction conditions to obtain BAB-type poly[ST-b-ethylene imine(EI)]. Morphologies of these block copolymer specimens cast from several solvents were observed by electron microscope. The results are discussed in some detail. 相似文献
10.
Koji Ishizu Takashi Fukutomi Toshio Kakurai 《Journal of polymer science. Part A, Polymer chemistry》1975,13(11):2453-2458
(MMA–α-methylstyrene)block copolymer was reacted with poly(α-methylstyryl)anion at ?78°C in a mixture of good tetrahydrofuran (THF) and poor methylcyclohexane solvents. The reaction conditions were chosen so as to produce graft copolymers made up of a backbone (AB-type block copolymer) and a single branched chain (1:2 graft copolymer). Gel permeation chromatograph (GPC), osmotic pressure measurement, and elemental analysis were used for the characterization of 1:2 graft copolymer. It appeared that poly(α-methylstyryl)anion reacted with the end pendant groups located farthest away from the branched point of AB-type block copolymer, when the dimensions of AB-type block copolymer molecule are small. 相似文献