Materials Literature
按标题、摘要、年份、主题和来源检索公开元数据。结果保留作者、摘要、分类与原始来源链接。
A kinetic study of the synthesis of poly(4-oxybenzoate) by melt-step growth polymerization using para-propionoxybenzoic acid is reported. The polycondensations obey second-order kinetics, irrespective of whether the reaction was catalyzed or uncatalyzed. Breaks are observed in the kinetic plots, suggesting the presenc…
The mechanical properties of the water-swellable rubber prepared by blending polychloroprene with precipitated silica, crosslinked sodium polyacrylate, polyethylene oxide, and vulcanizing agents—such as stress at break, strain at break, modulus, energy at break, and hardness—were studied before and after swelling with…
Abstract Field experience has shown that CO2 corrosion is considerably reduced at low partial pressures, unless more than 0.1 to 1 mM of acetic acid is present in the water. This paper shows that acetic species actually act as a weak inhibitor of the anodic dissolution reaction, and that the role of acetic acid is cle…
A drop in an axisymmetric extensional ow is studied using boundary integral methods to understand the effects of a monolayer-forming surfactant on a strongly deforming interface. Surfactants occupy area, so there is an upper bound to the surface concentration that can be adsorbed in a monolayer, Γ ∞ . The surface tens…
Free-radical-initiated grafting of maleic anhydride (MA) onto a polylactide (PLA) backbone was performed by reactive extrusion. A concentration of 2 wt % MA in the presence of 2,5-dimethyl-2,5-di-(tert-butylperoxy)hexane (Lupersol 101) as the free-radical initiator was used for all experiments. Two reaction temperatur…
Replacement of Na + by Li + has been achieved for sodalites of composition Na 8 [GaSiO 4 ] 6 X 2 and Na 8 [AlGeO 4 ] 6 X 2, where X is a halide, via nitrate melt at 240 °C. The resultant materials have been analyzed by Rietveld analysis of neutron powder diffraction data, and the derived structural parameters are comp…
ADVERTISEMENT RETURN TO ISSUEPREVCommunication to the...Communication to the EditorNEXTRing-Opening Copolymerization of (R)-β-Butyrolactone with Macrolide: A New Series of Poly(Hydroxyalkanoate)sYoji Hori, Hideyuki Hongo, and Toshimitsu HagiwaraView Author Information Central Research Laboratory, Takasago Internationa…
A method for the quantitative analysis of two-dimensional small-angle X-ray scattering (SAXS) patterns with fiber symmetry is proposed and applied to a series of images recorded during straining and relaxation cycles of a two-phase polymer sample at a synchrotron beamline.The studied longitudinal scattering originates…
A series of polybutadiene star polymers were produced by coupling living poly(butadienyl)lithium with dendritic chlorosilane linking agents. The theoretical arm numbers of the stars covered the range from 4 to 64, and the arm molecular weight was kept short with M n(arm) = 10 3 . MALDI-TOF MS and 1 H NMR spectroscopy…
The (hyper)polarizabilities obtained from the two valence bond state model including nonequilibrium solvation are compared to experiment. Specifically, the values of μ g 2 α zz (0) and μ g β zzz (0) in different solvents calculated from the model are compared to experimental measurements for several push−pull polyene…
A new open-framework zinc phosphate, [NH 3 (CH 2 ) 2 NH(CH 2 ) 2 NH 3 ] 2+ 2[Zn 2 PO 4 (HPO 4 )] -, possessing a layered architecture and consisting of alternating inorganic and organic layers, stabilized by multipoint hydrogen bonding has been synthesized hydrothermally. It has the following crystal data: monoclinic…
Single-crystal EPR studies of the Fe−O−Fe dimer, [enH 2 ][{Fe(HEDTA)} 2 O]·6H 2 O, have been performed at both X- and Q-band frequencies and room temperature. Resonances arising from the S‘ = 1, 2, and 3 states have been observed in the powder spectrum at Q-band frequency and analysis by spectral simulation has led to…
The chemical potential of adsorbed film inside cylindrical mesopores is dependent on the attractive interactions between the adsorbed molecules and adsorbent, the curvature of gas/adsorbed phase interface, and surface tension. A state equation of the adsorbed film is proposed to take into account the above factors. Ni…
A series of nanocrystalline solid solutions (CeO 2 ) 1 - x (BiO 1.5 ) x ( x = 0.0−0.5) were synthesized by mild hydrothermal conditions at 240 °C. The products were characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonanc…
A series of mesoporous vanadosilicate V−MCM-41 molecular sieves with variable Si/V ratios have been synthesized at room temperature using a minimum amount of template. The chemical environment of the vanadium centers in V−MCM-41 was investigated by powder X-ray diffraction (XRD), transmission electron microscopy (TEM)…
Liq. crystals displaying a Colh (columnar hexagonal) phase can display a cooperative chiral state. In the authors model the hexagonal symmetry is an integral feature that favors the chiral state. This latter point is also supported by the recent work on fluxional 8 vertex Zr4+ mesogens (Trazaska et al. 1999) with the…
The Fur apoprotein has been purified and reconstituted with Co2+ and Mn2+ ions. These samples have been analyzed by UV-visible, EPR, and 1H NMR spectroscopies, by XAS, and by magnetization measurements. The apo-Fur protein is able to bind one metal dication (Co2+ or Mn2+) per monomer. A saturation magnetization study…
Accurate measurements of the height and position of the preedge peak in Ti K-edge XANES (X-ray absorption near-edge structure) can distinguish 4-, 5-, and 6-fold coordination of Ti by O ( [4] Ti, [5] Ti, and [6] Ti, respectively), and mixtures thereof. This approach has been applied to titania−silica xerogels, (TiO 2…
Melt condensation of 1,5-bis(9-hydroxy-1,4,7-trioxanonyl)naphthalene ( 2 ) with bis-acid chlorides, adipoyl chloride ( 3a ), terephthaloyl chloride ( 3b ), and 3,6,9,12-tetraoxatetradecane bis-acid chloride ( 3c ), respectively, gives amorphous linear poly(ether−ester)s 1a − c, which contain 1,4,7-trioxanonyl (triethy…
This paper presents the rheology and morphology of immiscible polymer blends compatibilized by a polymer reaction at the interface. Nylon-6 was melt blended in a twin screw extruder with several different grades of maleated polypropylene at 10 and 20 wt %. The extent of polymer reaction at the interface is varied by v…