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1.
The polymeric products obtained from 2-furfurylidene methyl ketone and from furfural and acetone in the presence of base have been characterized by u.v. and i.r. spectral study, molecular weight estimation by vapour pressure osmometry and viscometric study of solutions in dioxane. Gel Permeation Chromatography of selected polymer samples was carried out to estimate polydispersity index; thermal behaviour was studied by thermogravimetric analysis. A likely course of the polymerization and the structure of polymers prepared from 2-furfurylidene methyl ketone (PFMK) are proposed. 相似文献
2.
Morten E. Simonsen Camilla Sønderby Erik G. Søgaard 《Journal of Sol-Gel Science and Technology》2009,50(3):372-382
In this work an inorganic polymer is developed based on Elkem microsilica and potassium hydroxide. Using experimental data and the partial charge model a model for the gelation is suggested based on the hydrolysis and condensation reactions occurring during synthesis. In addition the optimal composition of the binder system was determined using compressive strength test and solubility experiments. Based on partial charge calculations and experimental data for the hydroxide concentration and the viscosity obtained in this study it is suggested that the polymerization of the inorganic polymer is determined by the concentration of silica species. It was found that the alkalinity has a crucial effect on the condensation process. The optimal potassium hydroxide concentration used in the synthesis of the inorganic polymer was found to be around 3.5 M, which resulted in a compressive strength of the product in the region of 50 MPa. 相似文献
3.
Imai M Tanaka M Tanaka K Yamamoto Y Imai-Ogata N Shimowatari M Nagumo S Kawahara N Suemune H 《The Journal of organic chemistry》2004,69(4):1144-1150
Intermolecular hydroacylation between salicylaldehydes 1, 26-40 and 1,4-penta- or 1,5-hexadienes 4-13 by Rh-catalyst proceeded under mild reaction conditions to give a mixture of iso- and normal-hydroacylated products 14-25, 41-55, and 57-60. In the hydroacylation reaction, chelation of both salicylaldehyde and diene to the Rh-complex plays a crucial role. The ratio of iso- and normal-hydroacylated products could be regulated by the addition of salicylic acid or amines. The effects of various Rh-complexes, solvents, and additives were examined, and the plausible mechanisms of the catalytic cycle were proposed on the basis of the deuterium-labeling salicylaldehyde experiments. 相似文献
4.
Yuning Liu 《高分子科学杂志,A辑:纯化学与应用化学》2017,54(10):678-683
Triflate Ester of Calix[n]arene (n = 4, 6, 8) (TEC[n] (n = 4, 6, 8)) were synthesized based on a new synthetic route, then TEC[n] (n = 4, 6, 8) were further modified by reacting with low molecular weight Chitosan (CS) to get three kinds of new Calix[n]arene-Chitosan polymers (n = 4, 6, 8) (C[n]CSP (n = 4, 6, 8)) through Buchwald-Hartwig cross coupling reaction. The structures of the polymers were characterized by FT-IR, SEM, Elemental analyzer and 13C SSNMR. And the results found that Chitosan was successfully introduced to Calix[n]arene (n = 4, 6, 8) (C[n] (n = 4, 6, 8)) without any long-chain alkyl between Chitosan and Calixarene. These new polymers are partially substituted calixarene. The substitute degree of C[4]CSP, C[6]CSP and C[8]CSP is 17.75%, 21.08% and 54.53% respectively. And the optimal preparation conditions were discussed and the results were listed as following, molar ratio (1:2), catalyst (0.05 mmol), solvent ratio (1:1.5 (10 mL?1.0 mmol?1)) and reaction time (5h). 相似文献
5.
Robert F. Kovar F. E. Arnold 《Journal of polymer science. Part A, Polymer chemistry》1974,12(2):401-410
Novel phenylated quinoxaline tetraamines have been prepared and polymerized with 1,4,5,8-naphthalenetetracarboxylic acid in polyphosphoric acid solution. The resulting BBB-type polymers with pendant phenyl groups along the polymer backbone are soluble in m-cresol. The polymers, with inherent viscosities ranging from 0.3 to 0.6 dl/g in sulfuric acid, exhibited thermal stabilities near 500°C under nitrogen and near 400°C in air. 相似文献
6.
Antonio Cardone Carmela Martinelli Vita Pinto Francesco Babudri Maria Losurdo Giovanni Bruno Pinalysa Cosma Francesco Naso Gianluca M. Farinola 《Journal of polymer science. Part A, Polymer chemistry》2010,48(2):285-291
Fully fluorinated arylenevinylene polymers have been synthesized via a methodology based on the Stille cross‐coupling reaction and characterized by FTIR spectroscopy and MALDI‐TOF mass spectrometry. Investigation of thin film properties by cyclic voltammetry and ellipsometry shows that complete substitution of hydrogen atoms with fluorine atoms on the conjugated backbone of the poly(arylenevinylene)s results in a strong increase of the band gap. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 285–291, 2010 相似文献
7.
以非诺贝特(FNB)为模板分子,α-甲基丙烯酸(MAA)为功能单体,乙二醇二甲基丙烯酸酯(EDMA)为交联剂,采用本体聚合方法合成了FNB分子印迹聚合物(MIP)。IR和SEM表征的结果显示:FNB分子印迹聚合物中存在与模板分子相互作用的特征基团,与空白聚合物(NIP)的表面形态显著不同,说明MIP存在与模板分子相互识别的结合位点。采用静态平衡结合方法和Scatchard模型评价了FNB分子印迹聚合物的结合特性和识别机理,并考察了其选择性吸附能力。结果表明,FNB分子印迹聚合物存在能量相异的两类特异性结合位点,对FNB具有高选择吸附特性,饱和吸附量为6.363mg/g。 相似文献
8.
A. Ruttscheid 《European Polymer Journal》2005,41(8):1927-1933
By embedding hollow glass spheres of different sizes and densities into a matrix of crosslinked sodium polyacrylate, superabsorbent polymers were synthesized using a water-in-oil suspension polymerization. These glass-containing superabsorbents were capable of taking up water not only in form of a swollen polyacrylate gel, but also in form of additional free water between the glass spheres and the surrounding polyacrylate matrix. According to swelling measurements the maximum volume swelling degree of the glass-containing superabsorbents is in certain cases nearly double as large as the value of a superabsorbent without embedded glass spheres. 相似文献
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10.
New polyesters were synthesized using Krebs cycle acids. Poly(1, 4-butanediol dilactate succinate)(PBDS) and poly(1, 4-butanediol dilactate 2-acetoxy succinate)(PBDAS) were prepared by the polycondensation of 1, 4-butanediol dilactate with succinic anhydride and 2-acetoxy succinic acid, respectively. Poly(1, 4-butanediol succinate)(PBS) was also synthesized from 1, 4-butanediol and succinic anhydride. PBS/PBDS and PBS/PBDAS blends were prepared by the method of solvent casting. The effects of crystallization time and temperature onto melting behavior of PBS/PBDS and PBS/PBDAS blends were investigated by differential scanning calorimetry. The compatibility of each blend system was discussed using equilibrium melting point depressions. The biodegradation behavior was studied using PBS, PBDS, and PBDAS as the sole carbon source by Aspergillus niger. The molecular weights of the polymers which were obtained from GPC analysis decreased after degradation in five weeks. 相似文献
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12.
We report the synthesis and structure determination of PS-block-PEO functionalized by fluorocarbon end-group (C8F17) via an ester bridge. The synthesis was done by an anionic polymerization of PS and POE terminated by grafting 3-perfluorooctylpropanoyle chloride (C8F17-C2H4-COCl) onto PS-POE alcoholate. The structure has been characterized by a number of techniques: size exclusion chromatography, elementary analysis, UV spectroscopy, 1H nuclear magnetic resonance. Those analyses have allowed the determination of the real molar mass of the copolymers and the percentage functionalization. Because of their well-defined structure, these copolymers can be used as model compounds for the determination of structure-property relationships. 相似文献
13.
Cristofor I. Simionescu Mircea Grigoras 《Journal of polymer science. Part A, Polymer chemistry》1989,27(10):3201-3209
The polymerization of 9-anthrylmethyl propiolate using various initiating methods was studied with particular emphasis on the elucidation of the structure of the polymers. A polymer having a pure polyene structure was synthesized by anionic or anionic-coordination mechanism only. Thermal or transition metal halides polymerization led to a polymer possessing anthrylene methylene groups into the main polymer chain. A plausible mechanism for the obtention of this structure was proposed. 相似文献
14.
Yang Pan 《European Polymer Journal》2008,44(2):408-414
The synthesis and characterization of some new high-Tg photorefractive polymers, polyphosphazene P3-P8, were described. They were obtained via a post-azo coupling reaction. The resulting materials have been characterized by means of 1H NMR, 31P NMR, FT-IR, UV-vis, GPC and DSC. Chromophore contents up to 14 mol% have been realized. The polymers had high glass transition temperatures and good optical transparency. Measurements reveal that they possess relatively large magnitude of photoinduced birefringence. 相似文献
15.
A series of macrocyclic poly(2-vinylpyridine)&s were synthesized by high dilution (∼10−5 M) coupling of the two-ended living precursor dianions with 1, 2- and 1, 4-bis-(bromomethyl)benzene (1, 2- or 1, 4-DBX). SEC measurements indicate that the macrocycles contain less than 5% linear precursor and that the hydrodynamic size of the macrocycles is substantially (∼30%) less than that of the linear precursor. At very low MW, the sizes of macrocyclic and linear polymers differ less, particularly for the case of the 1, 2-DBX product. Viscometry measurements in THF of linear and macrocyclic polymers also indicated substantial size differences of linear and macrocyclic P2VP. The values of the glass transition temperature (Tg) for both the 1, 2- and 1, 4-DBX macrocycles were found to increase with decreasing MW as qualitatively predicted by entropy calculations. Thus, as the degree of polymerization decreases, the macrocyclic chains become conformationally stiffer and this is reflected by higher Tg values. The differences in Tg between linear and macrocyclic P2VP are quite large (∼40K) around a DP of 40 and decrease to values of a few degrees at a DP of around 200. These differences are diagnostically useful in estimating the linear content of the macrocycles below a DP of 100. 相似文献
16.
Wei Zhang Hao Jin Feng Zhou Zhihao Shen Dechun Zou Xinghe Fan 《Journal of polymer science. Part A, Polymer chemistry》2012,50(18):3895-3903
A monomer containing bent side chains with oxadiazole unit was synthesized. And it was copolymerized with polyfluorene at different ratios. The photophysical and electrochemical properties of the copolymers were characterized. The results show that the introduction of the oxidiazole‐containing side chains into the polymer reduces the lowest unoccupied molecular orbital level. And the steric hindrance of the side groups can effectively suppress the aggregation of the polymer backbones. Electroluminescent devices were fabricated with a configuration of indium tin oxide (ITO)/poly(3,4‐ethylenedioxythiophene (PEDOT):PSS/Sample/Ca/Al. All of the devices emit blue light. The device of the copolymer PFOXD50 shows the best performance with the maximum luminance of 1033 cd/m2 and the maximum current efficiency of 0.29 cd/A. Then a cyclometalated iridium complex monomer (ppy)2Ir(BrPhPyBr) was copolymerized with PFOXD50 at different ratios. The devices with the same configuration emit orange light. The efficiency generally increases with the increasing Ir content. Among them, the device of the copolymer PFOXDIr7 shows the best performance with the maximum luminance of 846 cd/m2 and the maximum current efficiency of 0.61 cd/A. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
17.
Five imine polymers, all containing 3,6-disubstituted carbazole ring in the main polymer chain, were synthesized by solution polycondensation of 3,6-diformyl (N-hexyl) carbazole with hydrazine, 1,4-diaminobenzene, 4,4′-diaminobiphenyl, 1,5-diaminonaphthalene and 3,6-(N-hexyl) diaminocarbazole. The polymers were analyzed by spectroscopic methods and compared with two imine models. 相似文献
18.
Thieo E. Hogen‐Esch 《Journal of polymer science. Part A, Polymer chemistry》2006,44(7):2139-2155
The synthesis and characterization by size exclusion chromatography, liquid chromatography, NMR, matrix‐assisted laser desorption/ionization, thermal analysis, and other techniques of well‐defined and narrow molecular weight distribution macrocyclic polystyrene (PS), poly(2‐vinylpyridine), poly(α‐methylstyrene), poly (2‐vinyl‐naphthalene) (P2VN), and poly(9,9‐dimethyl‐2‐vinylfluorene) (PDMVF) containing a single 1,4‐benzylidene, methylidene, or 9,10‐anthracenylidene unit are reviewed. The absorption and emission spectroscopy of PS, P2VN, and PDMVF is also discussed. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 2139–2155, 2006 相似文献
19.
T. Chad Willis John E. Sheats 《Journal of polymer science. Part A, Polymer chemistry》1984,22(5):1077-1084
Homopolymers of vinylruthenocene and its copolymers with methyl acrylate, styrene, and n-vinylpyrrolidinone have been prepared by free-radical polymerization. No evidence for the electron transfer termination mechanism postulated for polymerization of vinylferrocene was observed. Yields of soluble polymers were 40–90% with M w (4–25) × 103 and M w/M n = 3.0–13.2. TGA analysis showed little weight loss up to 300°C but rapid decomposition above 300°C. Polyvinylruthenocene is a highly brittle material with Tg above 250°C. Torsional braid analysis of the copolymer samples showed Tg in the range 90–130°C which in some samples increased upon cooling and reheating. Several samples showed weak thermal transitions occurring prior to or following Tg. The rise in Tg upon cooling and reheating is indicative of possible decomposition, crosslinking, or realignment of the polymer chains. 相似文献
20.
Doris Pospiech Hartmut Komber Dieter Voigt Dieter Jehnichen Liane Häußler Antje Gottwald Wolfram Kollig Kathrin Eckstein Angela Baier Karina Grundke 《Macromolecular Symposia》2003,199(1):173-186
The goal of the investigation presented here was to evaluate the influence of semifluorinated side chains on the bulk structure and the surface properties of polysulfones with different chain structure. Thus, segmented block copolymers consisting of polysulfone and semifluorinated aromatic polyester segments as well as polysulfones having semifluorinated side chains randomly distributed over the polymer backbone were synthesized and characterized. Oxydecylperfluorodecyl side chains were used because of their strong tendency for self-organization. The influence of the chain architecture on the self-organization as well as on the surface properties, particularly the wetting behavior, was examined. It could be shown that despite of the higher self-organizing tendency of block copolymers the surface properties of both polymer types are comparable and depend only on the concentration of side chains. 相似文献