Home About us Contact
|
Home About us Contact | ||
|
|
||
Water-soluble Poly (water-soluble + poly)
Selected AbstractsA Cationic Water-Soluble Poly(p -phenylenevinylene) Derivative: Highly Sensitive Biosensor for Iron-Sulfur Protein Detection,MACROMOLECULAR RAPID COMMUNICATIONS, Issue 10 2006Fan Cheng Abstract Summary: A new water-soluble cationic ammonium-functionalized poly(p -phenylenevinylene) (PPV-NEtMe) was successfully synthesized and exhibited high sensitivity (Ksv,=,6.9,×,107M,1) on rubredoxin, a type of anionic iron-sulfur (Fe-S) proteins. Further investigation showed that the biosensitivity of the cationic conjugated polymer is strongly dependent on the nature of the buffer solution and the concentration of the conjugated polymer used in the analyses. The schematic diagram of anionic rubredoxin detected by PPV-NEtMe. [source] Novel Water-Soluble Poly(m -benzamide)s: Precision Synthesis and Thermosensitivity in Aqueous SolutionMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9 2006Ryuji Sugi Abstract Summary: Chain-growth polycondensations of 3-aminobenzoic acid methyl esters 1a and 1b, bearing a tri- or tetra(ethylene glycol) methyl ether unit on the amino group, respectively, were carried out with lithium hexamethyldisilazide (LiHMDS) as a base and phenyl 4-methylbenzoate (2) as an initiator in THF at 0,°C. The poly(m -benzamide)s obtained in the presence of N,N,N,,N,-tetramethylethylenediamine (TMEDA) possessed narrow molecular weight distributions (,<,1.2) with molecular weights that were determined by the feed ratios of [1]0/[2]0. Poly1a and poly1b were each soluble in water and exhibited a lower critical solution temperature (LCST) in water. Furthermore, the phase separation in water depended on the length of the oligo(ethylene glycol) side chain and on the molecular weight and molecular weight distribution of poly1. Thermally sensitive water-soluble poly(m -benzamide)s. [source] Synthesis of poly(p -phenylene diamine) and its corrosion inhibition effect on iron in 1M HClJOURNAL OF APPLIED POLYMER SCIENCE, Issue 5 2008P. Manivel Abstract Water-soluble poly(p -phenylene diamine) was chemically synthesized. Its corrosion inhibition performance was evaluated for iron corrosion in 1M HCl at various concentrations, and the results were compared with that of the monomer. The corrosion inhibition properties were evaluated by polarization techniques and electrochemical impedance spectroscopy. The results showed that poly(p -phenylene diamine) was a more efficient corrosion inhibitor than the monomer and gave an 85% inhibition efficiency at a concentration of 50 ppm, whereas the monomer gave an efficiency of 73% at 5000 ppm. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 [source] Novel, biodegradable, functional poly(ester-carbonate)s by copolymerization of trans -4-hydroxy- L -proline with cyclic carbonate bearing a pendent carboxylic groupJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 10 2004Ren-Shen Lee Abstract Water-soluble poly(ester-carbonate) having pendent amino and carboxylic groups on the main-chain carbon is reported for the first time. This article describes the melt ring-opening/condensation reaction of trans -4-hydroxy- N -benzyloxycarbonyl- L -proline (N -CBz-Hpr) with 5-methyl-5-benzyloxycarbonyl-1,3-dioxan-2-one (MBC) at a wide range of molar fractions. The influence of reaction conditions such as catalyst concentration, polymerization time, and temperature on the number average molecular weight (Mn) and molecular weight distribution (Mw/Mn) of the copolymers was investigated. The polymerizations were carried out in bulk at 110 °C with 3 wt % stannous octoate as a catalyst for 16 h. The poly(ester-carbonate)s obtained were characterized by Fourier transform infrared spectroscopy, 1H NMR, differential scanning calorimetry, and gel permeation chromatography. The copolymers synthesized exhibited moderate molecular weights (Mn = 6000,14,700 g mol,1) with reasonable molecular weight distributions (Mw/Mn = 1.11,2.23). The values of the glass-transition temperature (Tg) of the copolymers depended on the molar fractions of cyclic carbonate. When the MBC content decreased from 76 to 12 mol %, the Tg increased from 16 to 48 °C. The relationship between the poly(N -CBz-Hpr- co -MBC) Tg and the compositions was in approximation with the Fox equation. In vitro degradation of these poly(N -CBz-Hpr- co -MBC)s was evaluated from weight-loss measurements and the change of Mn and Mw/Mn. Debenzylation of 3 by catalytic hydrogenation led to the corresponding linear poly(ester-carbonate), 4, with pendent amino and carboxylic groups. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2303,2312, 2004 [source] Helix Formation in Synthetic Polymers by Hydrogen Bonding with Native Saccharides in Protic MediaCHEMISTRY - A EUROPEAN JOURNAL, Issue 30 2006Minoru Waki Abstract Water-soluble poly(m -ethynylpyridine)s were designed to realize saccharide recognition in protic media. UV/Vis, 1H NMR, and fluorescence measurements revealed that the polymer forms a helical higher order structure by solvophobic interactions between the ethynylpyridine units in the protic medium. The resulting pore in the helix behaves like a binding pocket in proteins, by taking advantage of inwardly directed hydrogen-bonding functional groups of the polymers. Molecular recognition of native saccharides by the polymers was investigated by circular dichroism (CD). The chirality of the saccharide was transferred to the helical sense of the polymers, accompanied by the appearance of induced CDs (ICDs) in the absorptive region of the polymers. In MeOH/water (10/1), mannose and allose showed intense ICDs, and the apparent association constant between the polymer and D -mannose was 14,M,1. [source] Optical Detection of Mercury(II) in Aqueous Solutions by Using Conjugated Polymers and Label-Free Oligonucleotides,ADVANCED MATERIALS, Issue 11 2007X. Liu A conjugated-polymer-based "mix-and-detect" optical sensor for mercury ions is fabricated by using a water-soluble poly[3-(3,- N,N,N -triethylamino-1,-propyloxy)-4-methyl-2,5-thiophene hydrochloride] (PMNT) and a label-free, mercury-specific oligonucleotide (MSO) probe. PMNT binds to the Hg2+ -free MSO and the Hg2+,MSO complex in different ways, and exhibits distinguishable and specific optical responses to the target-induced conformation change. [source] "Click" Polymer-Supported Palladium Nanoparticles as Highly Efficient Catalysts for Olefin Hydrogenation and Suzuki Coupling Reactions under Ambient ConditionsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Cátia Ornelas Abstract Complexation of palladium(II) acetate [Pd(OAc)2] or dipotassium tetrachloropalladate [K2PdCl4] to "click" polymers functionalized with phenyl, ferrocenyl and sodium sulfonate groups gave polymeric palladium(II)-triazolyl complexes that were reduced to "click" polymer-stabilized palladium nanoparticles (PdNPs). Transmission electron microscopy (TEM) showed that reduction using sodium borohydride (NaBH4) produced PdNPs in the 1,3,nm range of diameters depending on the nature of the functional group, whereas slow reduction using methanol yielded PdNPs in the 22,25,nm range. The most active of these PdNPs (0.01% mol Pd), stabilized by poly(ferrocenyltriazolylmethyl)styrene, catalyzed the hydrogenation of styrene at 25,°C and 1 atm hydrogen, with turnover numbers (TONs) of 200,000. When stabilized by the water-soluble poly(sodium sulfonate-triazolylmethyl)styrene, the PdNPs (0.01% mol Pd) catalyze the Suzuki,Miyaura coupling between iodobenzene (PhI) and phenylboronic acid [PhB(OH)2] in water/ethanol (H2O/EtOH) at 25,°C with TONs of 8,200. This high catalytic activity is comparable to that obtained with "click" dendrimer-stabilized PdNPs under ambient conditions. [source] 5-aminoisoquinolin-1(2H)-one, a water-soluble poly (ADP-ribose) polymerase (PARP) inhibitor reduces the evolution of experimental periodontitis in ratsJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 2 2007Rosanna Di Paola Abstract Background: Poly (ADP-ribose) polymerase (PARP), a nuclear enzyme activated by strand breaks in DNA, plays an important role in the tissue injury associated with ischaemia-reperfusion and inflammation. Recent studies have demonstrated that PARP activation plays a crucial role in the pathogenesis of acute periodontal injury. Aim: We have investigated the effect of 5-aminoisoquinolin-1(2H)-one (5-AIQ), a water-soluble PARP inhibitor, in a rat model of periodontitis. Materials and Methods: Periodontitis was induced in rats by placing a 2/0 braided silk ligature around the lower left first molar. At day eight, the gingivomucosal tissue encircling the mandibular first molar was removed for biochemical and histological analysis. Results and Conclusions: Ligation significantly induced an increased neutrophil infiltration and a positive staining for PARP activation. Ligation significantly increased Evans blue extravasation in gingivomucosal tissue and alveolar bone destruction. Intraperitonial injection of 5-aminoisoquinolin-1(2H)-one (5-AIQ) (5 mg/kg daily for eight days) significantly decreased all of the parameters of inflammation as described above. This suggests that inhibition of PARP may represent a novel approach for the treatment of periodontal disease. [source] Water-soluble conjugated polymers: Synthesis and optical propertiesJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 22 2007Baohan Xie Abstract Two sets of water-soluble poly(phenylene vinylene)s were synthesized and their optical properties were studied. The aqueous solubility of all these polymers is rendered by pendant sulfonate groups. One set of polymers (polymer I series) contains, in addition to the sulfonate pendants, dimethoxy substituents, while the other (polymer II series) contains oligo(ethylene oxide) side chains. Within each set, polymers containing lithium (Ia and IIa), sodium (Ib and IIb), and potassium (Ic and IIc) counter ions were prepared. The two sets of polymers showed different properties from physical appearance (fiber vs film) to thermal properties and to optical properties. It was found that set I polymers, with shorter side chains, exhibit stronger aggregation in aqueous solutions than set II polymers, which led to their lower fluorescence quantum yields and lower polymer-to-MV2+ quenching efficiencies. Within each set, the effect of counter ions on optical properties was noted. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5123,5135, 2007 [source] Novel Water-Soluble Poly(m -benzamide)s: Precision Synthesis and Thermosensitivity in Aqueous SolutionMACROMOLECULAR RAPID COMMUNICATIONS, Issue 9 2006Ryuji Sugi Abstract Summary: Chain-growth polycondensations of 3-aminobenzoic acid methyl esters 1a and 1b, bearing a tri- or tetra(ethylene glycol) methyl ether unit on the amino group, respectively, were carried out with lithium hexamethyldisilazide (LiHMDS) as a base and phenyl 4-methylbenzoate (2) as an initiator in THF at 0,°C. The poly(m -benzamide)s obtained in the presence of N,N,N,,N,-tetramethylethylenediamine (TMEDA) possessed narrow molecular weight distributions (,<,1.2) with molecular weights that were determined by the feed ratios of [1]0/[2]0. Poly1a and poly1b were each soluble in water and exhibited a lower critical solution temperature (LCST) in water. Furthermore, the phase separation in water depended on the length of the oligo(ethylene glycol) side chain and on the molecular weight and molecular weight distribution of poly1. Thermally sensitive water-soluble poly(m -benzamide)s. [source] | |||||||||||||