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131.
Gabriel J. Summers M. Patrick Ndawuni Carol A. Summers 《Journal of polymer science. Part A, Polymer chemistry》2001,39(12):2058-2067
The quantitative synthesis of tertiary amine-functionalized polymers by atom transfer radical polymerization is reported. Tertiary amine-functionalized polystyrene was prepared with the adduct of 1-(bromoethyl)benzene with 1-(4-dimethyl-aminophenyl)-1-phenylethylene as an initiator in the atom transfer radical polymerization of styrene in the presence of a copper (I) bromide/2,2′-bipyridyl catalyst system. The polymerization proceeded via a controlled free-radical polymerization process to afford quantitative yields of the corresponding tertiary amine-functionalized polystyrene with predictable number-average molecular weights (1600–4400), narrow molecular weight distributions (1.09–1.31), and an initiator efficiency of 0.95. The polymerization process was monitored by gas chromatographic analysis. The tertiary amine-functionalized polymers were characterized by thin-layer chromatography, size exclusion chromatography, potentiometry, and spectroscopy. All experimental evidence was consistent with quantitative functionalization via the 1,1-diphenylethylene derivative. Polymerization kinetic measurements showed that the polymerization reaction followed first-order-rate kinetics with respect to monomer consumption and that the number-average molecular weight increased linearly with monomer conversion. © 2001 John Wiley & Sons, Inc. J Polym Sci A Part A: Polym Chem 39: 2058–2067, 2001 相似文献
132.
133.
Alp H. Alidedeoglu Adam W. York Dale A. Rosado Charles L. McCormick Sarah E. Morgan 《Journal of polymer science. Part A, Polymer chemistry》2010,48(14):3052-3061
The synthesis of well‐defined carboxylic acid‐functionalized glycopolymers prepared via one‐step postpolymerization modification of poly(N‐[3‐aminopropyl] methacrylamide) (PAPMA), a water‐soluble primary amine methacrylamide, in aqueous medium is demonstrated. PAPMA was first polymerized via aqueous reversible addition‐fragmentation chain transfer polymerization in aqueous buffer using 4‐cyanopentanoic acid dithiobenzoate as the chain transfer agent and 4,4′‐azobis(4‐cyanovaleric acid) (V‐501) as the initiator at 70 °C. The resulting well‐defined PAPMA was then conjugated with D ‐glucuronic acid sodium salt through reductive amination in alkaline medium (pH 8.5) at 45 °C. The successful bioconjugation was proven through proton (1H) and carbon (13C) nuclear magnetic resonance spectroscopy and matrix‐assisted laser desorption/ionization time of flight mass spectrometry analysis, which indicated near quantitative conversion. A similar bioconjugation reaction was conducted with poly(2‐aminoethyl methacrylate) (PAEMA) and poly(2‐aminoethyl methacrylate‐b‐poly(N‐[2‐hydroxypropyl]methacrylamide) (PAEMA‐b‐PHPMA). For the PAEMA homopolymers and block copolymers, however, lower conversion was obtained, most likely because of degradation reactions of PAEMA in alkaline medium. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 3052–3061, 2010 相似文献
134.
Ting‐Jui Hsiao Jing‐Cherng Tsai 《Journal of polymer science. Part A, Polymer chemistry》2010,48(8):1690-1698
Structurally well‐defined end‐functionalized syndiotactic polystyrene (sPS) can be prepared by conducting a simultaneous selective chain transfer reaction during the syndiospecific polymerization of styrene in the presence of vinylsilanes. The production of vinylsilane end‐capped sPS involves a unique selective chain transfer pathway via the incorporation of a terminal vinylsilane unit at the polymer chain end by 2,1‐insertion. This unusual insertion pattern situates the bulky silyl functional group at a closer β‐position from the active catalyst center, thus deactivating the propagating chain by a steric jam between the vinylsilane end group and the active catalyst. Subsequently, chain releasing by hydrogen addition (in the presence of H2) or by β‐elimination (in the absence of H2) can take place, which leads to the production of end‐functionalized sPS with precise controls of stereoregularity and of the location of functionality. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1690–1698, 2010 相似文献
135.
Emulsion copolymerization of styrene and a cationic monomer vinylbenzyl-isothiouronium chloride (VBIC) with initiation by 2,2 azobis(2-amidinopropane)-dihydrochloride (V-50) gave monodisperse latex particles. After post-stabilization with cationic or non-ionic surfactants, the colloids were diluted in basic buffers with concomitant deprotection of the sulfhydryl groups. Therefore, coupling reactions on the latex beads were possible. Coupling conditions were determined with Ellman's reagent.14C iodoacetamide and anti C-reactive protein antibody Fab fragments were immobilized and finally, the immunological activity of the sensitized latex was assessed. 相似文献
136.
The curing characteristics of carboxylic functionalized glucose resin (glucose maleic acid ester vinyl resin: GMAEV) and epoxy resin have been studied using DSC and FTIR methods. Exothermic reactions attributed to esterification and etherification reactions of the hydroxyl and carboxyl functionalities of GMAEV with the epoxy groups were identified. Exothermic reactions showed very different patterns according to the degree of carboxyl group substituent of GMAEV. The results showed that esterification reaction occurs in the early stage of cure and then etherification followed after completion of the esterification. A cured matrix containing epoxy resin and 50 wt.% of GMAEV was prepared and characterized. The cured matrix showed thermal stability up to 300 °C. The average glass transition temperature and storage modulus of the matrix were as high as 95 °C and 2700 MPa, respectively. The cured matrix of epoxy resin and GMAEV with higher degree of carboxyl group was found to have a lower density due to the formation of bulky groups in the crosslinks. 相似文献
137.
Chuan-Ming Jin Guo-Yuan Lu Yan Xu Qian Li Fang Liu Xiao-Zeng You 《Journal of chemical crystallography》2001,31(6):301-305
The crystal structure of 25,27-bis[(2-cyanophenyl)methoxy] calix[4]arene (C44H34N2O4) was determined by X-ray crystallographic analysis. It possesses space group R
, with a = b = 35.993(8) Å, c = 13.842(3) Å, = = 90°, = 120°, and D
calc = 1.260 mg/cm3 for Z = 18. Crystal data indicate that Compound 1 exists in a pinched-cone conformation with intramolecular hydrogen bonds. 相似文献
138.
Takahisa Iida Toshio Sugizaki Toshifumi Kageyama Osamu Moriya 《Journal of polymer science. Part A, Polymer chemistry》1998,36(4):655-663
Tributylstannylated silicic acid (TBSA), which was regarded as a protected polymeric silanol against self-condensation to give silica gel, was newly prepared from the reaction of water glass (WG) and bis(tributyltin) oxide (TBO). The ratios of Si/Sn contained in TBSA were determined by gravimetric analysis to be in the range of 2–3. The gelation of TBSA in usual organic solvents such as hexane, benzene, and dichloromethane was not observed over 3 weeks. In addition, TBSA was shown to be a convenient precursor for the preparations of silica gel modified with organofunctional groups. From the reaction of TBSA with trimethoxysilanes and aromatic alcohols, the silica gels havingorganofunctional groups were obtained with the elimination of a tributyltin group. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 655–663, 1998 相似文献
139.
The cross conjugated α-carbalkoxy enone system was found to be an excellent promoter for polyene cyclization. Under mild conditions, the reaction occurred readily with a high degree of regio- and stereoselectivity. Based on this facile process, an efficient method for the construction of highly functionalized decalin derivatives has been developed. 相似文献
140.
Yuzhen Zhao Xun Qiao Kexuan Li Siyi Ding Shaopeng Tian Huaping Ren 《Molecular Crystals and Liquid Crystals》2018,664(1):1-8
In the present work, the graphene oxide/blue phase liquid crystal composites and long aminoalkyl chains functionalized graphene/blue phase liquid crystal composites were prepared by doping the additives into a blue phase exhibiting liquid crystal host. It is found that the blue phase temperature range could be widened by dispersing a small amount of functionalized graphene. It suggests that anisotropic two-dimensional flake nanoparticles may be of great usefulness for stabilizing blue phases. 相似文献