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Oxide Moieties (oxide + moiety)

Distribution by Scientific Domains
Polymers and Materials Science60%

Selected Abstracts

Synthesis and characterization of soluble copolyimides containing chalcone and phosphine oxide moieties in the main chain

JOURNAL OF APPLIED POLYMER SCIENCE, Issue 1 2008
Wei Wang
Abstract The functional diamines 3,3,-diaminochalcone and bis(3-aminophenyl)-3,5-bis(trifluoromethyl)phenyl phosphine oxide were successfully prepared by simple and convenient procedures with short reaction times, and the overall yields were 78 and 70%, respectively. Copolyimides prepared from 3,3,-diaminochalcone, bis(3-aminophenyl)-3,5-bis(trifluoromethyl)phenyl phosphine oxide, and 4,4,-(hexafluoroisopropylidene)diphthalic anhydride exhibited excellent solubility in several organic solvents, such as dimethyl sulfoxide, N,N -dimethylformamide, N -methyl pyrrolidone, tetrahydrofuran, and acetone. They also showed very good thermal stability even up to 450°C for 5% weight loss (by thermogravimetric analysis) in nitrogen and a high glass-transition temperature up to 274°C (by differential scanning calorimetry) in nitrogen. The copolymers' adhesive and photoreactive properties were also investigated, and it was confirmed that the copolyimide containing chalcone and phosphine oxide moieties in the main chain had good adhesiveness and photoreactivity. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source]

ChemInform Abstract: Ring Opening of Cyclic Vinylogous Acyl Triflates Using Stabilized Carbanion Nucleophiles: Claisen Condensation Linked to Carbon,Carbon Bond Cleavage.

CHEMINFORM, Issue 37 2010
David M. Jones
Abstract Treatment of the cyclic triflates (I) and (VII) with carbanion nucleophiles provides acyclic alkynes bearing 1,3-diketone, ,-keto ester, ,-keto phosphonate, or ,-keto phosphine oxide moieties. [source]

Use of associating polymers as multifunctional thickeners: studies of Their structure in aqueous solutions via nmr, qels, fluorescence, And rheology measurements

INTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2007
Katsunori Yoshida
The solution properties of an associating polymer were studied by NMR, quasi-elastic light scattering (QELS), fluorescence, and rheology measurements. An associative thickening (AT) polymer was designed having a nonionic poly(ethylene oxide) backbone with long alkyl chains at both ends to achieve high viscosity even at relatively high salt concentrations and over a wide pH range. This study focuses on the associative state of the polymer in aqueous solutions at various polymer concentrations. In a fluorescence probe study using pyrene a spectral change in the I3/I1 ratio was observed for pyrene at a polymer concentration (Cp) of 3 x 10 -4%, indicating an apparent critical concentration (cmc) of the amphiphilic polymer. The viscosity, self-diffusion coefficient (Dsel), and hydrodynamic size (Rh) distribution measurements at various Cp all suggest that there is a second transition at Cp, 0.4%. Although we observed the discontinuity in viscosity, Dsel, and Rh at Cp, 0.4%, no changes in the relaxation times (T1 and T2) were recognized for either the alkyl chain or the ethylene oxide moiety of the polymer at C p= 0.1,1%. These data suggest that there are no structural changes or phase transitions at Cp, 0.4%, but that intermicellar networks are presumably formed by bridging of the end alkyl groups of the polymer, which is driven by hydrophobic forces. Because the polymer forms networks by hydrophobic interaction and the polymer itself is nonionic, the viscosity of the polymer solution was influenced very little by either the addition of salt or a pH change, as would be expected. The dynamic viscoelastic study revealed that the polymer solution exhibits a single mode Maxwell type relaxation behavior with a terminal relaxation time of about 0.61 s, which imparts a unique flow appearance to the polymer solutions. The time course measurements of the dynamic elastic modulus of the stratum corneum revealed that the polymer has excellent potential for skin softening. It was concluded that the associative thickening polymer not only is a useful thickener with a salt and pH tolerance but also has beneficial skincare effects. [source]

Synthesis and properties of amorphous blue-light-emitting polymers with high glass-transition temperatures

JOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 18 2001
V. Deimede
Abstract A series of soluble poly(arylene ether)s containing the phenylphosphine oxide moiety were synthesized by the polymerization of substituted oligophenylene diols with bis(fluorophenyl)phenylphosphine oxide. These amorphous polyethers had well-defined structures and showed blue photoluminescence combined with good thermal stability, especially when phenyl or ethoxy side groups were used. The glass-transition temperatures increased when the size of the oligophenylene segment increased from three to five rings or when the length of the alkoxy substituents decreased. Polymers with glass-transition temperatures up to 270 °C were obtained. The absorption and photoluminescent spectra shifted to longer wavelengths with an increase in the oligophenylene block. A redshift was also observed on photoluminescent spectra in the transition from solution to the solid state. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3168,3179, 2001 [source]