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1.
Hyung Soon Park Joo Hee Cho Junghun Suh 《Journal of polymer science. Part A, Polymer chemistry》1997,35(14):2935-2942
Three molecules of 5-(bromoacetyl)salicylate ( 1 ) complexed to uranyl UO ion were crosslinked with branchy poly(ethylenimine) (PEI) in DMSO by alkylation of amino groups of PEI with 1, leading to the formation of UO2(Sal) PEI. Upon demetalation of UO2(Sal) PEI with HCl, apo(Sal) PEI was obtained. Based on the pH dependence of log Kf for UO2(Sal) PEI, it was concluded that each uranyl binding site in UO2(Sal) PEI or apo(Sal) PEI contains three salicylate moieties. In terms of the equilibrium constant for formation of the uranyl complex, apo(Sal) PEI was found to be comparable to or better than the previously reported effective uranophiles. In terms of the rates for the formation of the uranyl complex, however, apo(Sal) PEI was far superior to those other uranophiles. © 1997 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 35 : 2935–2942, 1997 相似文献
2.
Dan Chen Wei Lu Ganhong Du Liming Jiang Jun Ling Zhiquan Shen 《Journal of polymer science. Part A, Polymer chemistry》2012,50(20):4191-4197
A new kind of polymeric chemosensor containing chiral naphthaldimine moiety in the side chain was synthesized by the reversible addition‐fragmentation chain transfer polymerization of N‐{[2‐(4‐vinylbenzyloxy)‐1‐naphthyl]‐methylene}‐(S)‐2‐phenylglycinol (VNP). The resulting polymers (PVNP) showed high selectivity for hydrogen sulfate relative to other anions including F?, Cl?, Br?, H2PO, CH3CO, and NO in tetrahydrofuran (THF) solution as judged from UV?vis, fluorescence, and circular dichroism spectrophotometric titrations. Compared with its monomer, the polymer has proven to be more attractive for detection of HSO in terms of sensitivity and reproducibility. Upon addition of the anion it gives remarkable spectral responses concomitant with detectable color change from colorless to pale yellow. Furthermore, the HSO‐induced CD or fluorescence signal can be totally reversed with addition of base and eventually recovered the initial state, leading to a reproducible molecular switch with two distinguished “on” and “off” states. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2012 相似文献
3.
James C. W. Chien Phillipe L. Bres 《Journal of polymer science. Part A, Polymer chemistry》1986,24(10):2483-2505
Polymerizations of ethylene by the MgCl2/ethylbenzoate/p-cresol/AlEt3 TiCl4-AlEt3/methyl-p-toluate (CW-catalyst) have been studied. The initially formed active site concentration, [Ti] has a maximum value of 50% of total titanium at 50°C and lower values at other temperatures. The Ti decays rapidly to Ti sites with conc. ca. 10 mol %/mol Ti. The rate constants for four chain transfer processes have been obtained at 50°C: for transfer with AlEt3, k = 2.1 × 10?4 s?1 and k = 4.8 × 10?4 s?1; for transfer with monomer, k = 3.6 × 10?3 (M s)?1 and K = 8.3 × 10?3 (M s)?1; for β-hydride transfer, k = 7.2 × 10?4 s?1 and k = 4.9 × 10?4 s?1; and transfer with hydrogen, k = 4.0 × 10?3 torr1/2 s? and k = 5.1 × 10?3 torr1/2 s?1. The rate constants for the termination assisted by hydrogen is k = 1.7 (M1/2 torr1/2 S)?1. If monomer is assisting termination as was observed for propylene polymerization, then k = 7.8 (M3/2 s)?1. Values of all the rate constants can be higher or lower at other temperatures. Detailed comparisons were made with the results of propylene polymerizations. There are more than four times as many Ti active sites for ethylene polymerization than there are for stereospecific polymerization of propylene; the difference is more than a factor of two for the Ti sites. Certain rate constants are nearly the same for both monomers while others are markedly different. Some of the differences can be explained by stereoelectronic effects. 相似文献
4.
Pierre Lebreton Bernard Boutevin 《Journal of polymer science. Part A, Polymer chemistry》2000,38(10):1834-1843
Acrylamide was polymerized in acetonitrile at 82 °C with a perfluorinated azo‐derivative initiator. The polymerization proceeded heterogeneously. Varying amounts of initiator and monomer were used. The activation energy was deduced from three experiments carried out at 59, 71, and 82 °C. The following kinetic law, deviating a great deal from the classical law, was obtained: R ∼ [I2][M](0.05% < [I2]o/[M]o < 1.00%) and R ∼ [I2][M](1% < [I2]o/[M]o < 7%). These results can be interpreted in light of the contribution of primary radical termination and the emergence of occlusion. The development of a new kinetic relationship allowed us to confirm the existence of both of these termination reactions. The calculation of the kprt /ki · kp ratio was also achieved. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 1834–1843, 2000 相似文献
5.
Markus Döbbelin Cristina Pozo‐Gonzalo Rebeca Marcilla Raúl Blanco José L. Segura Jose A. Pomposo David Mecerreyes 《Journal of polymer science. Part A, Polymer chemistry》2009,47(12):3010-3021
Novel poly(3,4‐ethylenedioxythiophene) (PEDOT) polymers bearing imidazolium‐ionic liquid moieties were synthesized by electrochemical polymerizations. For this purpose, new functional monomers were synthesized having an 3,4‐ethylenedioxythiophene (EDOT) unit and an imidazolium‐ionic liquid with different anions such as tetrafluoroborate (BF), bis(trifluoromethane)sulfonimide ((CF3SO2)2N?), and hexafluorophosphate (PF). Next, polymer films were obtained by electrochemical synthesis in dicholoromethane solutions. Obtained polymers were characterized, revealing the characteristics of PEDOT in terms of electrochemical and spectroelectrochemical properties, FTIR, 1H NMR, and AFM microscopy. Interestingly, the hydrophobic character of electropolymerized films could be modified depending on the anion type. The hydrophobicity followed the trend PF > (CF3SO2)2N? > BF > pure PEDOT as determined by water contact angle measurements. Furthermore, the polymers could be dissolved in a range of polar organic solvents such as dimethylformamide, propylene carbonate, and dimethyl sulfoxide making these polymers interesting candidates for wet processing methods. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 3010–3021, 2009 相似文献
6.
V. Percec A. D. Asandei Q. Zheng 《Journal of polymer science. Part A, Polymer chemistry》2000,38(19):3631-3655
(S)‐1‐Cyano‐2‐methylpropyl‐4′‐{[4‐(8‐vinyloxyoctyloxy)benzoyl]oxy}biphenyl‐ 4‐carboxylate [ (S)‐11 ] and (R)‐1‐cyano‐2‐methylpropyl‐4′‐{[4‐(8‐vinyloxyoctyloxy)benzoyl]oxy}biphenyl‐4‐carboxylate [( R)‐11 ] enantiomers, both greater than 99% enantiomeric excess, and their corresponding homopolymers, poly[ (S)‐11 ] and poly[ (R)‐11 ], with well‐defined molecular weights and narrow molecular weight distributions were synthesized and characterized. The mesomorphic behaviors of (S)‐11 and poly[ (S)‐11 ] are identical to those of (R)‐11 and poly[ (R)‐11 ], respectively. Both (S)‐11 and (R)‐11 exhibit enantiotropic SA, S, and SX (unidentified smectic) phases. The corresponding homopolymers exhibit SA and S phases. The homopolymers with a degree of polymerization (DP) less than 6 also show a crystalline phase, whereas those with a DP greater than 10 exhibit a second SX phase. Phase diagrams were investigated for four different pairs of enantiomers, (S)‐11 /( R)‐11 , (S)‐11 /poly[ (R)‐11 ], and poly[ (S)‐11 ]/poly[ (R)‐11 ], with similar and dissimilar molecular weights. In all cases, the structural units derived from the enantiomeric components are miscible and, therefore, isomorphic in the SA and S phases over the entire range of enantiomeric composition. Chiral molecular recognition was observed in the SA and SX phases of the monomers but not in the SA phase of the polymers. In addition, a very unusual chiral molecular recognition effect was detected in the S phase of the monomers below their crystallization temperature and in the S phase of the polymers below their glass‐transition temperature. In the S phase of the monomers above the melting temperature and of the polymers above the glass‐transition temperature, nonideal solution behavior was observed. However, in the SA phase the monomer–polymer and polymer–polymer mixtures behave as an ideal solution. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 3631–3655, 2000 相似文献
7.
Zhaohui Yang Hailin Cong Weixiao Cao 《Journal of polymer science. Part A, Polymer chemistry》2004,42(17):4284-4288
Diazonium group–substituted polystyrene (PS–N) micrometer‐sized spheres with narrow distribution were prepared from highly crosslinked polystyrene particles. Then a composite sphere was prepared with the micro‐PS–N sphere as core and submicrometer‐sized poly(styrene‐methyl methacrylate‐acrylic acid) [P(S‐MMA‐AA)] colloids or nanometer‐sized SiO2 particles as shell via columbic interaction. The ionic linkages between the core and shell convert to covalent bonds in the thermal treatment process. As a result, the composite sphere becomes very stable toward polar solvents as well as toward ultrasonic treatment. A hollow SiO2 micrometer‐sized sphere then was achieved by removing the core under sintering conditions (700 °C). © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4284–4288, 2004 相似文献
8.
Koji Ishizu Masataka Nunomura Takashi Fukutomi 《Journal of polymer science. Part A, Polymer chemistry》1987,25(4):1163-1175
Soluble microgels with several pendant vinyl groups were synthesised by radical copolymerization of methyl methacrylate (MMA) with p-divinyl benzene (p-DVB). The competitive reactions of intermolecular and intramolecular crosslinkings of these microgels were carried out at 40°C in the presence of 1-buten-3-ol as a degradative chain transfer agent. The rate constant of intermolecular crosslinking (k) was estimated by GPC (gel permeation chromatography) analysis on the polymer produced from intermolecular propagation between bimolecules. The k depended strongly on the internal structure of microgels. Network formation was discussd inclusive of informations for the rate constant of intramolecular crosslinking (k). 相似文献
9.
James C. W. Chien Tsunle Ang 《Journal of polymer science. Part A, Polymer chemistry》1986,24(9):2217-2230
Decene-1 was polymerized with the CW catalyst and fractionated by precipitation technique. Light-scattering and viscometric measurements on these fractions established the relationship [η] = 5.19 × 10?3 M . The unperturbed mean square end-to-end distance is (〈R〉/M)1/2 = (6.17 ± 0.34) × 10?9. Light-scattering data is consistent with a relatively stiff molecule with length of L = 1.75 × 10?5 cm for poly(decene-1) with MW = 397,000. Its mean square radius of gyration 〈R〉 is 2.79 × 10?11 cm.2 The ratio of L2/〈R〉 = 11 is close to the theoretical ratio of 12 for this kind of macromolecule. 相似文献
10.
Norio Tsubokawa Yu Jian Yasuo Sone 《Journal of polymer science. Part A, Polymer chemistry》1988,26(10):2715-2724
The cationic ring-opening polymerization of oxepane was found to be initiated by carbon black having acylium perchlorate (CO+CIO) groups, which were introduced by the reaction of acyl chloride groups with silver perchlorate. It was confirmed that polyoxepane, i.e., poly(oxyhexamethylene), was propagated from CO+CIO groups on carbon black and effectively grafted on the surface. The rate of the polymerization and the percentage of grafting of poly(oxyhexamethylene) remarkably increased by the addition of epichlorohydrin (ECH) as a promoter: the percentage of grafting in the presence of ECH increased to about 100% with an increase in conversion. Furthermore, CO+CIO groups on carbon black have an ability to initiate the cationic ring-opening copolymerization of oxepane with ECH to give poly(oxepane-co-ECH) with various composition. The ring-opening copolymerization of oxepane with phthalic anhydride was also initiated by CO+CIO groups to give polyether ester, i.e., poly(hexamethylene phthalate) containing poly(oxyhexamethylene) sequence. In the copolymerization, polyether or polyether ester was effectively grafted from carbon black based on the propagation of these polymers from CO+CIO groups. 相似文献
11.
Li‐Ming Huang Guo Cheng Huang Ten‐Chin Wen 《Journal of polymer science. Part A, Polymer chemistry》2006,44(22):6624-6632
Poly(2,5‐dimethoxyaniline) (PDMA)–Ag composites were successfully obtained through the oxidative polymerization of 2,5‐dimethoxyaniline in poly(styrene sulfonic acid) with CH3SO3Ag and AgNO3 as oxidants. In situ ultraviolet–visible spectroscopy results showed that the growth rate of PDMA was strongly affected by CH3SO and NO. The coupling reaction of PDMA and NO was proposed to explain the lower growth rate of PDMA with AgNO3 as the oxidant in comparison with CH3SO3Ag. X‐ray photoelectron spectroscopy and Fourier transform infrared spectroscopy were used to validate the proposed coupling reaction through the monitoring of the side products and oxidized state of PDMA. The results showed that there were more side products and lower oxidized states for the composite structure in the presence of NO than in the presence of CH3SO, and this agreed with the proposal. Transmission electron microscopy showed that the Ag nanoparticles had almost the same size, regardless of the anions. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 6624–6632, 2006 相似文献
12.
Gorkem Yilmaz Selim Beyazit Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2011,49(7):1591-1596
The free radical promoted cationic polymerization cyclohexene oxide (CHO), was achieved by visible light irradiation (λinc = 430–490 nm) of methylene chloride solutions containing thioxanthone‐fluorene carboxylic acid (TX‐FLCOOH) or thioxanthone‐carbazole (TX‐C) and cationic salts, such as diphenyliodonium hexafluorophosphate (Ph2I+PF) or silver hexafluorophosphate (Ag+PF) in the presence of hydrogen donors. A feasible initiation mechanism involves the photogeneration of ketyl radicals by hydrogen abstraction in the first step. Subsequent oxidation of ketyl radicals by the oxidizing salts yields Bronsted acids capable of initiating the polymerization of CHO. In agreement with the proposed mechanism, the polymerization was completely inhibited by 2,2,6,6‐tetramethylpiperidinyl‐1‐oxy and di‐2,6‐di‐tert‐butylpyridine as radical and acid scavengers, respectively. Additionally polymerization efficiency was directly related to the reduction potential of the cationic salts, that is, Ag+PF (E = +0.8 V) was found to be more efficient than Ph2I+PF (E = ?0.2 V). In addition to CHO, vinyl monomers such as isobutyl vinyl ether and N‐vinyl carbazole, and a bisepoxide such as 3,4‐epoxycyclohexyl‐3′,4′‐epoxycyclohexene carboxylate, were polymerized in the presence of TX‐FLCOOH or TX‐C and iodonium salt with high efficiency. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
13.
The electrosynthesis of polyparaphenylene films (PPP) by oxidation of benzene or biphenyl on a Pt electrode was studied in different organic media. Film formation was possible only if the solvent had acidic properties according to the Lewis concept, and if the water content of this medium was less than 5 × 10?2M. Addition of an excess of P2O5 or CuCl2 into the medium increased the acidity and improved the adherence and the homogeneity of the films considerably. PPP films were electroactive and conductive if the electrolysis was carried out in the presence of salts containing BF, SbF, PF anions; they were insulating with perchlorate salts. IR analysis of these polymers showed highly crosslinked structures and the chains were constituted of about 10 para coupled phenyl moieties. 相似文献
14.
Bin Luan Bao‐Qing Zhang Cai‐Yuan Pan 《Journal of polymer science. Part A, Polymer chemistry》2006,44(1):549-560
A well‐defined branched copolymer with PLLA‐b‐PS2 branches was prepared by combination of reversible addition‐fragmentation transfer (RAFT) polymerization, ring‐opening polymerization (ROP), and atom transfer radical polymerization (ATRP). The RAFT copolymerization of methyl acrylate (MA) and hydroxyethyl acrylate (HEA) yielded poly(MA‐co‐HEA), which was used as macro initiator in the successive ROP polymerization of LLA. After divergent reaction of poly(MA‐co‐HEA)‐g‐PLLAOH with divergent agent, the macro initiator, poly(MA‐co‐HEA)‐g‐PLLABr2 was formed in high conversion. The following ATRP of styrene (St) produced the target polymer, poly(MA‐co‐HEA)‐g‐(PLLA‐b‐PS2). The structures, molecular weight, and molecular weight distribution of the intermediates and the target polymers obtained from every step were confirmed by their 1H NMR and GPC measurements. DSC results show one T = 3 °C for the poly(MA‐co‐HEA), T = ?5 °C, T= 122 °C, and T = 157 °C for the branched copolymers (poly(MA‐co‐HEA)‐g‐PLLA), and T = 51 °C, T = 116 °C, and T = 162 °C for poly(MA‐co‐HEA)‐g‐(PLLA‐b‐PS2). © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 44: 549–560, 2006 相似文献
15.
Virgil Percec Anatoliy V. Popov Ernesto Ramirez‐Castillo Jorge F. J. Coelho Luis A. Hinojosa‐Falcon 《Journal of polymer science. Part A, Polymer chemistry》2004,42(24):6267-6282
Non‐transition metal‐catalyzed living radical polymerization (LRP) of vinyl chloride (VC) in water at 25–35 °C is reported. This polymerization is initiated with iodoform and catalyzed by Na2S2O4. In water, S2O dissociates into SO that mediates the initiation and reactivation steps via a single electron transfer (SET) mechanism. The exchange between dormant and active propagating species also includes the degenerative chain transfer to dormant species (DT). In addition, the SO2 released from SO during the SET process can add reversibly to poly(vinyl chloride) (PVC) radicals and provide additional transient dormant ~SO radicals. This novel LRP proceeds mostly by a combination of competitive SET and DT mechanisms and, therefore, it is called SET‐DTLRP. Telechelic PVC with a number‐average molecular weight (Mn) = 2,000–55,000, containing two active ~CH2? CHClI chain ends and a higher syndiotacticity than the commercial PVC were obtained by SET‐DTLRP. This PVC is free of structural defects and exhibits a higher thermal stability than commercial PVC. SET‐DTLRP of VC is carried out under reaction conditions related to those used for its commercial free‐radical polymerization. Consequently, SET‐DTLRP is of technological interest both as an alternative commercial method for the production of PVC with superior properties as well as for the synthesis of new PVC‐based architectures. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6267–6282, 2004 相似文献
16.
17.
Vincent T. Calabrese Arshad Khan 《Journal of polymer science. Part A, Polymer chemistry》1999,37(15):2711-2717
Amylose-iodine (AI) complex has been synthesized in aqueous solution without added KI. Complex formation (with solid iodine in amylose solution) is maximized at approximately 35°C and decreases beyond that temperature. Ion-selective electrode (ISE) measurements of an aqueous solution of iodine and AI complex indicate that there is no change in the I− ion concentration when the complex forms. This suggests that I− ions (including I, I, and others) cannot be involved in forming the AI complex. The present work also reports a new and simple method for providing both the iodine-binding capacity (IBC) of amylose and the dissociation mechanism for the AI complex. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 2711–2717, 1999 相似文献
18.
Katherine B. Aubrecht Karen Chang Marc A. Hillmyer William B. Tolman 《Journal of polymer science. Part A, Polymer chemistry》2001,39(2):284-293
In quest of new, single‐site catalysts for cyclic ester polymerizations, a series of mononuclear yttrium(III) complexes of N,N′‐bis(trimethylsilyl)benzamidinate ([LTMS]−) and hindered N,N′‐bis‐(2,6‐dialkylaryl)toluamidinates ([LEt]−, aryl = Et2C6H3, and [LiPr]−, aryl = iPr2C6H3) were synthesized and characterized by X‐ray diffraction: LY(μ‐Cl)2Li(TMEDA) ( 1 ), LY(OC6H2tBu2Me) ( 2 ), LY(OC6H3Me2)2Li(THF)4 ( 3 ), LY(μ‐OtBu)2Li(THF) ( 4 ), LiPrY[N(SiMe2H)2]2(THF) ( 5 ), LY(THF)(Cl)(μ‐Cl)Li(THF)3 ( 6 ), and LY[N(SiMe2H)2] ( 7 ). Coordination numbers ranging from five to seven were observed, and they appeared to be controlled by the steric bulk of the supporting amidinate and alkoxide, phenoxide, or amide coligands. Complexes 2 – 5 and 7 are active catalysts for the polymerization of D,L ‐lactide (e.g., with 2 and added benzyl alcohol, 1000 equiv of D,L ‐lactide were polymerized at room temperature in less than 1 h, with polydispersities less than 1.5). The neutral complexes 2 , 5 , and 7 were more effective than the anionic complexes 3 and 4 . In addition, the presence of the more hindered amidinate ligands [LEt]− and [LiPr]− on yttrium‐amides slowed the polymerizations ( 7 < 5 < Y[N(SiMe2H)2]3). © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 284–293, 2001 相似文献
19.
Jan Budziski 《International journal of quantum chemistry》2004,97(4):832-843
An algorithm for evaluation of two‐center, three‐electron integrals with the correlation factors of the type rr and rrr as well as four‐electron integrals with the correlation factors rrr and rrr in the Slater basis is presented. This problem has been solved here in elliptical coordinates, using the generalized and modified form of the Neumann expansion of the interelectronic distance function r for k ≥ ?1. Some numerical results are also included. © 2003 Wiley Periodicals, Inc. Int J Quantum Chem, 2004 相似文献
20.
Frederick W. King 《International journal of quantum chemistry》1999,72(2):93-99
A simplified analysis is presented for the evaluation of the three‐electron one‐center integrals of the form ∫rrrrrred r 1d r 2d r 3, for the cases i, j, k, ≥−2, l=−2, m≥−1, n≥−1. These integrals arise in the calculation of lower bounds for energy levels and certain relativistic corrections to the energy when Hylleraas‐type basis sets are employed. Convergence accelerator techniques are employed to obtain a reasonable number of digits of precision, without excessive CPU requirements. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 72: 93–99, 1999 相似文献