共查询到20条相似文献,搜索用时 15 毫秒
1.
Doris Pospiech Liane Häußler Dieter Jehnichen Wolfram Kollig Kathrin Eckstein Karina Grundke 《Macromolecular Symposia》2003,198(1):421-434
The goal of the investigation presented here is the development of extremely hydrophobic materials based on polysulfone that can be applied, for instance, as fouling-resistant membrane materials. The concept used is the addition of semifluorinated polymers to polysulfone in suitable blend compositions. The influence of molecular parameters like chain structure of the semifluorinated polymer (segmented block copolymers, random copolymers) and segment molecular weight on the state of phase separation in the bulk and its influence on the surface properties have been systematically examined. It could be shown that segmented block copolymers with semifluorinated polyester segments with intermediate segment molecular weight are more suitable in blends with polysulfone than random polysulfone copolymers having semifluorinated side chains with respect to form homogeneous thin films (coatings) with highly non-wetting properties. 相似文献
2.
Karunakaran Radhakrishnan Karen A. Switek Marc A. Hillmyer 《Journal of polymer science. Part A, Polymer chemistry》2004,42(4):853-861
Two sets of styrene‐based semifluorinated block copolymers, one with a perfluoroether pendant group and another with a perfluoroalkyl group, were synthesized by atom transfer radical polymerization. Microphase separation of the block copolymers was established by small‐angle X‐ray scattering and differential scanning calorimetry (DSC). DSC measurements also showed that the perfluoroether‐based polymer had a low glass‐transition temperature (?44 °C). Contact‐angle measurements indicated that the semifluorinated block copolymers had low surface energies (ca. 13 mJ/m2). These materials hold promise as low‐surface‐energy additives or surfactants for supercritical CO2 applications. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 853–861, 2004 相似文献
3.
C. Amato 《Journal of fluorine chemistry》2003,124(2):169-175
The α,ω-diiodoperfluorooctane is added to undecyl-10-en-1-ol through AIBN initiation yielding the monoadduct in good yield (1,2-dichloroethane, 52%). This is added to N-allylphthalimide (AIBN initiation, 1,2-dichloroethane, 81%). The resulting diiodo compound is hydrodeiodinated with Bu3SnH (toluene, 70%) and the alcohol function is converted to thioacetate through the Mitsunobu reaction (PPh3, DIAD, THF, 75%). The two protecting groups, phthalimide and thioacetate, are removed with hydrazine to give the expected amino terminated semifluorinated long-chain alkanethiol (ethanol, 80%). This compound has been designed in order to form mixed fluorinated self-assembled monolayers (SAMs) with semifluorinated long-chain alkanethiol giving access to a new platform system for biosensors. Similar results are reported starting from the α,ω-diiodoperfluorohexane. 相似文献
4.
Yuxiang Zhou Rajeswari M. Kasi 《Journal of polymer science. Part A, Polymer chemistry》2008,46(20):6801-6809
We report the synthesis and characterization of a series of novel diblock copolymers, poly(cholesteryl methacrylate‐b‐2‐hydroxyethyl methacrylate) (PCMA‐b‐PHEMA). Monomers, cholesteryl methacrylate (CMA) and 2‐(trimethylsiloxy)ethyl methacrylate (HEMA‐TMS), were prepared from methyacryloyl chloride and 2‐hydroxyethyl methacrylate, respectively. Homopolymers of CMA, PCMA, with well‐defined molecular weights and polydispersity indices (PDI), were prepared by reversible addition fragmentation and chain transfer (RAFT) method. Precursor diblock copolymers, PCMA‐b‐P(HEMA‐TMS), were synthesized using PCMA as macromolecular chain transfer agent and monomer, HEMA‐TMS. Product diblock copolymers, PCMA‐b‐PHEMA, were prepared by deprotecting trimethylsilyl units in the precursor diblock copolymers using acid catalysts. Detailed molecular characterization of the precursor diblock copolymers, PCMA‐b‐P(HEMA‐TMS), and the product diblock copolymers, PCMA‐b‐PHEMA, confirmed the composition and structure of these polymers. This versatile synthetic strategy can be used to prepare new amphiphilic block copolymers with cholesterol in one block and hydrogen‐bonding moieties in the second block. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 6801–6809, 2008 相似文献
5.
Synthesis and characterization of double hydrophilic block copolymers containing semi-rigid and flexible segments 下载免费PDF全文
Alice M. Savage Elizabeth Ullrich Stacey M. Chin Zachary Kiernan Caitlyn Kost S. Richard Turner 《Journal of polymer science. Part A, Polymer chemistry》2015,53(2):219-227
3-Methyl-(E)-stilbene (3MSti) and 4-(diethylamino)-(E)-stilbene (DEASti) monomers are synthesized and polymerized separately with maleic anhydride (MAn) in a strictly alternating fashion using reversible addition-fragmentation chain transfer (RAFT) polymerization techniques. The optimal RAFT chain transfer agents (CTAs) for each copolymerization affect the reaction kinetics and CTA compatibilities. Psuedo-first order polymerization kinetics are demonstrated for the synthesis of poly((3-methyl-(E)-stilbene)-alt-maleic anhydride) (3MSti-alt-MAn) with a thiocarbonylthio CTA (methyl 2-(dodecylthiocarbonothioylthio)−2-methylpropionate, TTCMe). In contrast, a dithioester CTA (cumyl dithiobenzoate, CDB) controls the synthesis of poly((4-(diethylamino)-(E)-stilbene)-alt-maleic anhydride) (DEASti-alt-MAn) with pseudo-first order polymerization kinetics. DEASti-alt-MAn is chain extended with 4-acryloylmorpholine (ACMO) to synthesize diblock copolymers and subsequently converted to a double hydrophilic polyampholyte block copolymers (poly((4-(diethylamino)-(E)-stilbene)-alt-maleic acid))-b-acryloylmorpholine) (DEASti-alt-MA)-b-ACMO) via acid hydrolysis. The isoelectric point and dissociation behavior of these maleic acid-containing copolymers are determined using ζ-potential and acid–base titrations, respectively. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 219–227 相似文献
6.
Rosselli S Ramminger AD Wagner T Lieser G Höger S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(15):3481-3491
Shape-persistent macrocycles based on the phenyl-ethynyl-butadienyl backbone containing two extraannular hydroxyl groups were prepared by the oxidative coupling of the appropriate phenylethynyl oligomers. Carbodiimide-directed coupling with independently synthesized polystyrene carboxylic acid oligomers led to ABA coil-ring-coil block copolymers in which the central macrocycle serves as rigid and the polystyrene oligomers as flexible elements. Depending on the size of the coil blocks, these structures aggregate in cyclohexane into supramolecular hollow cylindrical brushes in which the rigid core is surrounded by the flexible matrix. However, in the solid state it is not possible to identify a morphology in which isolated channels based on aggregated macrocycles are embedded in a matrix of polystyrene. Detailed X-ray and electron diffraction studies on samples prepared from a solution in cyclohexane under equilibrium conditions show that the material adopts a lamellar morphology in the solid state in which columns of macrocycles are aggregated into layers which are separated by polystyrene. 相似文献
7.
Long‐Cheng Gao Xing‐He Fan Zhi‐Hao Shen Xiaofang Chen Qi‐Feng Zhou 《Journal of polymer science. Part A, Polymer chemistry》2009,47(2):319-330
The controlled radical polymerization of mesogen‐jacketed liquid crystalline polymers has triggered great interests in synthesis of complex structures as well as well‐defined linear homopolymers with controlled molecular weight and narrow molecular weight distributions. This review highlights the synthetic strategies of controlled radical polymerization of linear homopolymers, star polymers, superbranched polymers, graft polymers, block copolymers, star block copolymers, and so on. The employed living methods include nitroxide‐mediated radical polymerization and atom transfer radical polymerization. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 319–330, 2009 相似文献
8.
Several new semifluorinated compounds and polymers modified with these groups were synthesized and investigated. The polymer supports for these mesomorphic groups were styrene-diene block copolymers in which the semifluorinated groups were attached to a hydroxy-modified diene block. The characteristics of the smectic phase formed and its effect on the self-ordering behavior of the block copolymers were examined. 相似文献
9.
Alberto Concellón Eva Blasco Milagros Piñol Luis Oriol Isabel Díez Cristina Berges Carlos Sánchez‐Somolinos Rafael Alcalá 《Journal of polymer science. Part A, Polymer chemistry》2014,52(22):3173-3184
A new methacrylate containing a 2,6‐diacylaminopyridine (DAP) group was synthesized and polymerized via RAFT polymerization to prepare homopolymethacrylates (PDAP) and diblock copolymers combined with a poly(methyl methacrylate) block (PMMA‐b‐PDAP). These polymers can be easily complexed with azobenzene chromophores having thymine (tAZO) or carboxylic groups with a dendritic structure (dAZO), which can form either three or two hydrogen bonds with the DAP groups, respectively. The supramolecular polymers were characterized by spectroscopic techniques, optical microscopy, TGA, and DSC. The supramolecular polymers and block copolymers with dAZO exhibited mesomorphic properties meanwhile with tAZO are amorphous materials. The response of the supramolecular polymers to irradiation with linearly polarized light was also investigated founding that stable optical anisotropy can be photoinduced in all the materials although higher values of birefringence and dichroism were obtained in polymers containing the dendrimeric chromophore dAZO. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014 , 52, 3173–3184 相似文献
10.
Sergey Chernyy Zhongli Wang Jacob Judas Kain Kirkensgaard Anders Bakke Kell Mortensen Sokol Ndoni Kristoffer Almdal 《Journal of polymer science. Part A, Polymer chemistry》2017,55(3):495-503
Narrowly dispersed diblock copolymers containing poly(methyl methacrylate) [PMMA] or poly(nonafluorohexyl methacrylate) [PF9MA] as the first block and poly(ferrocenylmethyl methacrylate) [PFMMA] as the second block, were prepared by anionic polymerization for the first time. Disordered bulk morphologies in the case of PMMA‐b‐PFMMA were observed and explained in terms of low Flory–Huggins interaction parameter (χ ≤ 0.04). In the case of PF9MA‐b‐PFMMA hexagonally packed cylinder morphology (HEX) was substantiated from TEM and SAXS observations. Furthermore, high incompatibility between PF9MA and PFMMA blocks allowed for the formation of well‐ordered ferrocene containing cylinders on silica substrate upon exposure of the thin films to a saturated solvent vapor. It was shown that the cylinder orientation, parallel or perpendicular to the surface, could easily be controlled by appropriate choice of the solvent and without the need for preliminary surface modification, for example by means of grafted brush layer. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 495–503 相似文献
11.
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
12.
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
13.
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
14.
Hideyuki Kaneko Junji Saito Nobuo Kawahara Shingo Matsuo Tomoaki Matsugi Norio Kashiwa 《Journal of polymer science. Part A, Polymer chemistry》2009,47(3):812-823
A new method to prepare the polypropylene (PP) macroinitiator for controlled radical polymerization was described. Bromination of terminally-unsaturated PP was carried out by using N-bromosuccinimide and 2,2′-azobis(isobutyronitrile) to give a brominated PP (PP-Br), that has allylic bromide moieties at or near the chain ends. Thus, the obtained PP-Br was successfully used as a macroinitiator for radical polymerization of styrene, methyl methacrylate, and n-butyl acrylate using a copper catalyst system. From 1H NMR analysis, it was confirmed that the chain extension polymerization was certainly initiated from allylic bromide moieties with high efficiency, leading to the PP-based block copolymers linking the polar segment. From differential scanning calorimetry, it was observed that peak melting temperature of block copolymers was higher than that of PP-Br and the obtained PP-PS block copolymers with different compositions of each segment demonstrated the unique morphological features due to the microphase separation between both segments. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 812–823, 2009 相似文献
15.
X. Andrew Guo Allen D. Hunter Jie Chen 《Journal of polymer science. Part A, Polymer chemistry》1994,32(15):2859-2866
The synthesis and characterization of five novel organonickel-organosilicon alternating copolymers having the repeating unit ? C6F4? Ni‘PBu3’2? C6F4? SiR2? [where SiR2 = ? SiMe2? , ? SiMe‘Hex’? , ? SiPh2? , ? SiMe2? O? SiMe2? , and ? SiMe2? ‘CH2’6? SiMe2? ] are reported. The model compounds Ni‘PR3’2‘1,4-C6F4SiMe3’2‘PR3 = PMePh2 or PBu3’ were prepared via reactions of Ni‘PR3’2‘1,4-C6F4Li’2 with 2 equiv of SiMe3Cl, and were characterized by conventional analytical and spectroscopic measurements. The Polymers were prepared from the reactions of Ni‘PBu3’2‘1,4-C6F4Li’2 with 1 equivalent of SiMe2Cl2 ‘polymer 1 , M w = 15,800’, SiMe ‘Hex’ Cl2 ‘polymer 2 , M w = 7300’, SiPh2Cl2 ‘polymer 3 , M w = 8600’, O‘SiMe2Cl’2 ‘polymer 4 , M w = 13,900’ and ‘CH2’6‘SiMe2Cl’2 ‘polymer 5 , M w = 19,700’. The molecular weights for each polymer were fully determined by both GPC and VPO. The multinuclear ‘1H-, 19F-, and 31P [1H]’-NMR, FTIR, and UV-Visible spectroscopic data for each polymer unambiguously establishes its repeating unit structure. The observations indicate that introduction of the silyl or siloxane units into the organonickel backbones has remarkably decreased the chain rigidity of the organonickel-organosilicon polymers compared to their rigid rod organonickel analogues ‘i.e., ? [? C6F4? Ni‘PR3’2? ]n? ’. © 1994 John Wiley & Sons, Inc. 相似文献
16.
Coil-helix and sheet-helix block copolymers via macroinitiation from telechelic ROMP polymers 下载免费PDF全文
Elizabeth Elacqua Anna Croom Diane S. Lye Marcus Weck 《Journal of polymer science. Part A, Polymer chemistry》2017,55(18):2991-2998
Coil-helix and sheet-helix block copolymers are synthesized by combining the ring-opening metathesis polymerization (ROMP) of norbornene or paracyclophanediene with the anionic polymerization of phenyl isocyanide. Key to the design is the use of an μ-ethynyl palladium (II) functionalized chain-transfer agent (CTA) that can be exploited in a stepwise manner for the termination of ROMP and the initiation of the anionic polymerization. Both the coil- and sheet-macroinitiators, and the ensuing covalent block copolymers, are analyzed using 1H NMR spectroscopy and gel-permeation chromatography. In all cases, the Pd-end group is maintained and all polymers demonstrate a monomodal distribution with dispersities (Đ) of 1.1–1.4. The resulting helix-coil and helix-sheet block copolymers formed by the macroinitiation route still demonstrate their intrinsic properties (fluorescence, preferential helix-sense). © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 2991–2998 相似文献
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18.
John Q. Buquoi Dennis W. Smith Jr. Scott T. Iacono 《Journal of polymer science. Part A, Polymer chemistry》2011,49(20):4441-4447
Fluorinated arylene vinylene ether (FAVE) polymers were prepared from the base‐promoted addition of commercial 2,2‐bis(4‐hydroxyphenyl)hexafluoropropane (6F bisphenol A) to aryl trifluorovinyl ether (TFVE), 2,2′‐bis(4‐trifluorovinyloxybiphenyl)‐1,1,1,3,3,3‐hexafluoropropane. The step‐growth polymerization kinetics by using stoichiometric NaH and catalytic Cs2CO3 were investigated by monitoring the 19F NMR signals of the aryl TFVEs. The nth order kinetic model was used to determine rate constants over a series of programmed temperatures. Polymerization using stoichiometric NaH resulted in second‐order kinetics with an activation energy of 59 kJ/mol. This model kinetic study provided insight into the mechanistic pathways of the FAVE polymer system that has recently shown a lot of interest in many areas of materials science. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
19.
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
20.
Cagatay Altinkok Baris Kiskan Yusuf Yagci 《Journal of polymer science. Part A, Polymer chemistry》2011,49(11):2445-2450
The preparation of soluble and processable polybenzoxazine precursors capable of forming high performance networks is an important field of research with a broad spectrum of application. This study demonstrates an approach that utilizes aromatic sulfonediamine, bisphenol‐A, and formaldehyde in Mannich‐type polycondesation to prepare polybenzoxazine precursor. The structure of the oligomeric precursor (Mn = 2600) was confirmed by FTIR and 1H NMR spectral analysis. The precursor contained both sulfone and benzoxazine ring structures in the backbone. It was shown that small amount of ring‐opened phenolic groups were also present. Thermally activated self‐curing behavior of precursor in the absence of catalyst was studied by differential scanning calorimetry. Thermal properties of the cured polymers were also investigated by thermo gravimetric analysis. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献