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Many Organic Solvents (many + organic_solvent)
Selected AbstractsNew Low-Molecular-Mass Gelators Based on L -Lysine: Amphiphilic Gelators and Water-Soluble OrganogelatorsHELVETICA CHIMICA ACTA, Issue 1 2004Masahiro Suzuki The new L -lysine alkali-metal salts 1,5 (M+=Na+ and K+) with different alkyl groups at the N, -position were easily synthesized, and their hydro- and organogelation properties were investigated. All compounds were H2O-soluble, and some salts, especially the potassium salts, functioned as a hydrogenator that could gel water below 2 wt-%. These salts also had organogelation abilities for many organic solvents. [source] Synthesis and characterization of amphiphilic biodegradable poly(glutamic acid- co -lactic acid- co -glycolic acid) by direct polycondensationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2008Dedai Lu Abstract Poly(glutamic acid- co -lactic acid- co -glycolic acid) (PGLG), an amphiphilic biodegradable copolymer, was synthesized by simply heating a mixture of L -glutamic acid (Glu), DL -lactic acid, and glycolic acid with the present of stannous chloride. The unique branched architecture comprising of glutarimide unit, polyester unit, and polyamide unit was confirmed by NMR spectrum. The PGLG was soluble in many organic solvents and aqueous solution of sodium hydroxide (pH , 9.0). The thermal properties were evaluated using thermogravimetric analysis and differential scanning calorimetry. Molecular weights were determined by 1H NMR end-group analysis and GPC, respectively, and the results indicated that the higher Glu content resulted in a decrease of the molecular weight. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Highly stable electrochromic polyamides based on N,N -bis(4-aminophenyl)- N,,N,-bis(4- tert -butylphenyl)-1,4-phenylenediamineJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 9 2009Sheng-Huei Hsiao Abstract A new triphenylamine-containing aromatic diamine monomer, N,N -bis(4-aminophenyl)- N,,N,-bis(4- tert -butylphenyl)-1,4-phenylenediamine, was synthesized by an established synthetic procedure from readily available reagents. A novel family of electroactive polyamides with di- tert -butyl-substituted N,N,N,,N,-tetraphenyl-1,4-phenylenediamine units were prepared via the phosphorylation polyamidation reactions of the newly synthesized diamine monomer with various aromatic or aliphatic dicarboxylic acids. All the polymers were amorphous with good solubility in many organic solvents, such as N -methyl-2-pyrrolidinone (NMP) and N,N -dimethylacetamide, and could be solution-cast into tough and flexible polymer films. The polyamides derived from aromatic dicarboxylic acids had useful levels of thermal stability, with glass-transition temperatures of 269,296 °C, 10% weight-loss temperatures in excess of 544 °C, and char yields at 800 °C in nitrogen higher than 62%. The dilute solutions of these polyamides in NMP exhibited strong absorption bands centered at 316,342 nm and photoluminescence maxima around 362,465 nm in the violet-blue region. The polyamides derived from aliphatic dicarboxylic acids were optically transparent in the visible region and fluoresced with a higher quantum yield compared with those derived from aromatic dicarboxylic acids. The hole-transporting and electrochromic properties were examined by electrochemical and spectro-electrochemical methods. Cyclic voltammograms of the polyamide films cast onto an indium-tin oxide-coated glass substrate exhibited two reversible oxidation redox couples at 0.57,0.60 V and 0.95,0.98 V versus Ag/AgCl in acetonitrile solution. The polyamide films revealed excellent elcterochemical and electrochromic stability, with a color change from a colorless or pale yellowish neutral form to green and blue oxidized forms at applied potentials ranging from 0.0 to 1.2 V. These anodically coloring polymeric materials showed interesting electrochromic properties, such as high coloration efficiency (CE = 216 cm2/C for the green coloring) and high contrast ratio of optical transmittance change (,T%) up to 64% at 424 nm and 59% at 983 nm for the green coloration, and 90% at 778 nm for the blue coloration. The electroactivity of the polymer remains intact even after cycling 500 times between its neutral and fully oxidized states. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 2330,2343, 2009 [source] Synthesis and properties of silica/polystyrene/polyaniline conductive composite particlesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 2 2005Chia-Fen Lee Abstract In this study, silica/polystyrene/polyaniline (SiO2/PS/PANI) conductive composite particles were synthesized by four sequential reactions. The nanosized SiO2 particles were synthesized from tetraethoxysilane (TEOS) by a sol,gel process with water as the solvent medium, followed by a surface modification with triethoxyvinylsilane; then the surface modified SiO2 particles were used as seeds to synthesize SiO2/PS composite particles with soapless seeded emulsion polymerization. Finally, the SiO2/PS particles were used as seeds to synthesize the SiO2/PS/PANI conductive composite particles. The sol,gel process of SiO2, the effect of surface modification, and several other factors that influenced polymerization of styrene in the soapless seeded emulsion polymerization will be discussed. Either potassium persulfate (KPS) or 2,2,-azobis(isobutyramidine) dihydrochloride (AIBA) was used as the initiator to synthesize the uniform SiO2/PS particles successfully, and the cross-section morphology of the SiO2/PS particles was found to be of a core,shell structure, with SiO2 as the core, and PS as the shell. The SiO2/PS particles were well dispersed in many organic solvents. In the following step to synthesize SiO2/PS/PANI conductive composite particles, sodium dodecyl sulfate (SDS) played an important role, specifically, to absorb aniline onto the surfaces of the SiO2/PS particles to carry out the polymerization of aniline over the entire surface of the particles. The conductivity of the SiO2/PS/PANI composite particles approached that of semiconductive materials. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 342,354, 2005 [source] Synthesis and characterization of novel soluble triphenylamine-containing aromatic polyamides based on N,N,-bis(4-aminophenyl)- N,N,-diphenyl-1,4-phenylenediamineJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 16 2002Guey-Sheng Liou Abstract A new triphenylamine-containing aromatic diamine, N, N,-bis(4-aminophenyl)- N, N,-diphenyl-1,4-phenylenediamine, was prepared by the condensation of N,N,-diphenyl-1,4-phenylenediamine with 4-fluoronitrobenzene, followed by catalytic reduction. A series of novel aromatic polyamides with triphenylamine units were prepared from the diamine and various aromatic dicarboxylic acids or their diacid chlorides via the direct phosphorylation polycondensation or low-temperature solution polycondensation. All the polyamides were amorphous and readily soluble in many organic solvents such as N, N -dimethylacetamide and N -methyl-2-pyrrolidone. These polymers could be solution cast into transparent, tough, and flexible films with good mechanical properties. They had useful levels of thermal stability associated with relatively high glass-transition temperatures (257,287 °C), 10% weight-loss temperatures in excess of 550 °C, and char yields at 800 °C in nitrogen higher than 72%. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 2810,2818, 2002 [source] | ||||||||||