共查询到20条相似文献,搜索用时 15 毫秒
1.
Lars Kilian Zhen‐He Wang Timothy E. Long 《Journal of polymer science. Part A, Polymer chemistry》2003,41(19):3083-3093
Core‐cleavable star polymers were synthesized by the coupling of living anionic poly(alkyl methacrylate) arms with either dicumyl alcohol dimethacrylate (DCDMA) or 2,5‐dimethyl‐2,5‐hexanediol dimethacrylate (DHDMA). This synthetic methodology led to the formation of star polymers that exhibited high molecular weights and relatively narrow molecular weight distributions. The labile tertiary alkyl esters in the DCDMA and DHDMA star polymer cores were readily hydrolyzed under acidic conditions. High‐molecular‐weight star polymer cleavage led to well‐defined arm polymers with lower molecular weights. Hydrolysis was confirmed via 1H NMR spectroscopy and gel permeation chromatography. Thermogravimetric analysis (TGA) of the star polymers demonstrated that the DCDMA and DHDMA star polymer cores also thermally degraded in the absence of acid catalysts at 185 and 220 °C, respectively, and the core‐cleavage temperatures were independent of the arm polymer composition. The difference in the core‐degradation temperatures was attributed to the increased reactivity of the DCDMA‐derived cores. TGA/mass spectrometry detected the evolution of the diene byproduct of the core degradation and confirmed the proposed degradation mechanism. The DCDMA monomer exhibited a higher degradation rate than DHDMA under identical reaction conditions because of the additional resonance stabilization of the liberated byproduct, which made it a more responsive cleavable coupling monomer than DHDMA. © 2003 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 3083–3093, 2003 相似文献
2.
Atsushi Ikeda Masaru Kawaguchi Yoshio Suzuki Tsukasa Hatano Munenori Numata Seiji Shinkai Akio Ohta Makoto Ohta 《Journal of inclusion phenomena and macrocyclic chemistry》2000,38(1-4):163-170
The calixarene-fullerene interaction,which causes only a slight change in the absorptionspectra, has been substantiated by calorimetricmeasurements: the H° values arecomparable with those obtained from the associationconstants estimated by a spectroscopic method. Furthermore, we determined the association constantbetween homooxacalix[3]arene and [60]fullerenederivatives with a porphyrin moiety by fluorescencespectra. 相似文献
3.
Lixin Xiao Hidekazu Shimotani Masaki Ozawa Jing Li Nita Dragoe Kazuhiko Saigo Koichi Kitazawa 《Journal of polymer science. Part A, Polymer chemistry》1999,37(18):3632-3637
A novel [60]fullerene pearl-necklace polymer, poly(4,4′-carbonylbisphenylene trans-2-[60]fullerenobisacetamide), was synthesized by a direct polycondensation of trans-2-[60]fullerenobisacetic acid with 4,4′-diaminobenzophenone in the presence of large excesses of triphenyl phosphite and pyridine. In the present polymer, [60]fullerene pearls and diamine linkers were attached to each other by methano-carbonyl connectors. The molecular weight Mw of the polymer was determined to be 4.5 × 104 on the basis of the TOF-MS, and a GPC analysis of the polymer using polystyrene standards showed a weight-average molecular weight of 5.3 × 104. The UV-vis spectrum of the resultant polymer in N,N-dimethylacetamide (DMAc) exhibited a broad absorption (λmax 310 nm, ε 2.1 × 104 L · mol−1 · cm−1), tailing to longer wavelengths, and a fluorenscence peak centered at 550 nm was observed in DMAc. There was observed a large downfield-shift of the cyclopropane methyne proton in the 1H-NMR spectra from 4.57 ppm of the ethyl ester to 5.78 ppm of the polyamide. These observations indicate that the present polyamide is a high-molecular-weight [60]fullerene pearl-necklace polymer and that the cyclopropane rings are efficient to make the [60]fullerene cages and the diamine components conjugatable. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 3632–3637, 1999 相似文献
4.
Romanova I. P. Yusupova G. G. Nafikova A. A. Kovalenko V. I. Sinyashin O. G. 《Russian Chemical Bulletin》2002,51(8):1491-1496
A single di(azahomo)[60]fullerene isomer was prepared for the first time by the reaction between [60]fullerene and isocyanurato-substituted azide. The structure of the product was established by 1H and 13C NMR, UV, and IR spectroscopy. 相似文献
5.
《高分子科学杂志,A辑:纯化学与应用化学》2013,50(12):1263-1273
Abstract A new synthetic approach for the fabrication of core‐shell like conducting elastomers was described. The approach utilized the facile intermolecular self‐assembly of poly(dimethylsiloxane) (PDMS) in DMSO leading to formation of a core particle, while soluble oligoaniline (A x ) segments dispersed in the solution phase resembling a shell overlayer for building the morphology. This morphology was demonstrated by bis[penta(tetraanilinofullereno)] bis(aminopropyl)poly(dimethylsiloxane) [PDMS‐(F5A4)2] triblock co‐oligomers synthesized using a functionalized C60 derivative as a linker. Observation of 1H NMR spectroscopic responses on the PDMS particle formation in DMSO‐d 6 is consistent with the proposed core‐shell geometry with oligoaniline moieties located at the shell overlayer. 相似文献
6.
Yu Chen Yun Zhao Ruifang Cai Zu-En Huang Lixiang Xiao 《Journal of Polymer Science.Polymer Physics》1998,36(14):2653-2663
The novel C60–styrene copolymers with different C60 contents were prepared in sodium naphthalene-initiated anionic polymerization reactions. Like the pure polystyrene, these copolymers exhibited the high solvency in many common organic solvents, even for the copolymer with high C60 content. In the polymerization process of C60 with styrene an important side reaction, i.e., reaction of C60 with sodium naphthalene, would occur simultaneously, whereas crosslinking reaction may be negligible. 13C-NMR results provided an evidence that C60 was incorporated covalently into the polystyrene backbone. In contrast to pure polystyrene, the TGA spectrum of copolymer containing ∼ 13% of C60 shows two plateaus. The polystyrene chain segment in copolymer decomposed first at 300–400°C. Then the fullerene units reptured from the corresponding polystyrene fragments attached directly to the C60 cores at 500–638°C. XRD evidence indicates that the degree of order of polymers increases with the fullerene content increased in terms of crystallography. Incorporation of C60 into polystyrene results in the formation of new crystal gratings or crystallization phases. In addition, it was also found that [60]fullerene and its polyanion salts [C60n−(M+)n, M = Li, Na] cannot be used to initiate the anionic polymerization of some monomers such as acrylonitrile and styrene, etc.© 1998 John Wiley & Sons, Inc. J. Polym. Sci. B Polym. Phys. 36: 2653–2663, 1998 相似文献
7.
Synthesis of ABCD‐type miktoarm star copolymers and transformation into zwitterionic star copolymers
Xiaojun Wang Junpo He Yuliang Yang 《Journal of polymer science. Part A, Polymer chemistry》2007,45(21):4818-4828
ABCD‐type 4‐miktoarm star copolymers of styrene (St), α‐methylstyrene (αMSt), tert‐butyl methacrylate (tBuMA), and 4‐vinylpyridine (4VP) were synthesized via anionic polymerization using 1,3‐bis(1‐phenylvinyl)benzene (m‐DDPE) as the linking molecule. The synthetic route was rationally designed with respect to the reactivity of individual propagating anion towards the double bond of m‐DDPE. Thus the synthesis includes several consecutive key reactions, for example, the monoaddition of polystyryllithium towards m‐DDPE, the polymerization of tBuMA initiated by the resulting monoadduct to produce a diblock macromonomer, the coupling of the macromonomer with poly(α‐methylstyryl)lithium to form a 3‐arm star anion, and the polymerization of 4‐vinylpyridine initiated by the star anion. These reactions were conducted either in a one‐pot process, in which the diblock macromonomer was in situ coupled with poly(α‐methylstyryl)lithium, or in a batch polymerization process, in which the same diblock macromonomer was separated. The final product was hydrolyzed to produce a zwitterionic miktoarm star copolymer, which was soluble at lower pH but insoluble in neutral and basic solution. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4818–4828, 2007 相似文献
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Romanova I. P. Kalinin V. V. Nafikova A. A. Yakhvarov D. G. Zverev V. V. Kovalenko V. I. Rusinov G. L. Plekhanov P. V. Charushin V. N. Sinyashin O. G. 《Russian Chemical Bulletin》2003,52(1):173-178
The reaction of [60]fullerene with 2-azidopyrimidines affords fullerenoimidazopyrimidines, whose electron affinity is higher than that of nonmodified C60. 相似文献
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Masaki Ozawa Jing Li Kentaro Nakahara Lixin Xiao Hiroharu Sugawara Koichi Kitazawa Kazushi Kinbara Kazuhiko Saigo 《Journal of polymer science. Part A, Polymer chemistry》1998,36(17):3139-3146
A novel series of polyamides having [60]fullerene moieties in the main chain were synthesized by a direct polycondensation of [60]fullerenobis(acetic acid) or [60]fullerenobis(acetic acid)/isophthalic acid mixture with a diamine in the presence of triphenyl phosphite and pyridine. Various properties of the polyamides were characterized by means of IR, GPC, TGA, DSC, UV–visible, and photoluminescence. The molecular weight Mw of the [60]fullerene-containing polyamides was observed in the range from about 300,000 to 3,000; upon the changing of the ratio of [60]fullerenobis(acetic acid)/isophthalic acid in the starting mixture, the resulting Mw decreased with increasing the ratio. Most of the thermal and optical properties gradually changed as the ratio changed; the major optical absorption band in visible range exhibited a significant tailing, which shifted toward a longer wavelength, while the photoluminescence spectrum red-shifted with increasing [60]fullerene content. © 1998 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 36: 3139–3146, 1998 相似文献
12.
The synthesis of a new linear benzo[3]phenylene-[60]fullerene dyad 1 is achieved over 10 steps in 15% overall yield by using an efficient sequence combining a double cobalt(I)-mediated cyclotrimerization with a Bingel reaction. 相似文献
13.
单加成环丙烷富勒烯膦酸酯衍生物的合成与电化学性能 总被引:1,自引:0,他引:1
在Mn(OAc)3•2H2O催化下, C60分别和亚甲基二膦酸四乙酯、氰基亚甲基膦酸二乙酯或乙氧羰基亚甲基膦酸二乙酯在氯苯中回流, 生成3个单加成环丙烷富勒烯膦酸衍生物C60C(R)PO(OEt)2 [1, R=PO(OEt)2; 2, R=COOEt; 3, R=CN]. 与以前报道的Bingel反应法相比, 该方法副产物少并且缩短了反应时间. 采用循环伏安法发现1, 2的还原电位相对于C60发生负移, 而3的还原电位相对于C60却正移40 mV, 表明引入象氰基一样具有很强吸电子能力的取代基团, 可以改善富勒烯球的电化学性能, 合成电子接受能力较强的富勒烯衍生物. 相似文献
14.
Romanova I. P. Yusupova G. G. Yakhvarov D. G. Larionova O. A. Mochul"skaya N. N. Sidorova L. P. Charushin V. N. Zverev V. V. Sinyashin O. G. 《Russian Chemical Bulletin》2003,52(10):2171-2174
The first representative of the pyrimidine-substituted [60]fullereno[1,2-b]aziridines was synthesized by the reaction of fullerene C60 with 2-azido-4,6-diphenylpyrimidine. 2-(Azahomo[60]fullereno)-4,6-diphenylpyrimidine was found to be formed as a by-product. The electrochemical properties of the adducts were studied. 相似文献
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Dirk Kuckling Agnes Wycisk 《Journal of polymer science. Part A, Polymer chemistry》2013,51(14):2980-2994
Stimuli-responsive star polymers gain more and more interest over the last decades due to their unique properties compared to their linear counterparts. The branched structure for instance has influence on the responsive behavior of these polymers. This review offers an overview of stimuli-responsive star polymers generated by different polymerization techniques, e.g. anionic and controlled radical polymerization (CRP). Beside conventional branched homopolymers different other types like block copolymers, miktoarm star copolymers, core crosslinked star polymers (CCS) and comb polymers are also presented. Furthermore their responsive behavior in solution or immobilized on a substrate, and their applications are outlined. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013, 51, 2980–2994 相似文献
17.
Mohamad Nasser‐Eddine Simone Reutenauer Christelle Delaite Guy Hurtrez Philippe Dumas 《Journal of polymer science. Part A, Polymer chemistry》2004,42(7):1745-1751
Three alternative routes, using the heterobifunctional macroinitiator technique, have been developed to obtain polystyrene–poly(tert‐butyl methacrylate)–poly(ethylene oxide) triarm star block copolymers. Only the route showing the reverse initiation of tert‐butyl methacrylate on potassium alkoxide leads to the pure star, whereas the other strategies lead to incomplete initiation because of either an increase in the side reactions, such as transesterification, or a decrease in the accessibility toward bulky catalysts. These limits are linked to the particular location of the initiating group at the junction of the two blocks of the copolymer precursor. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 1745–1751, 2004 相似文献
18.
The homodinuclear bismetallacyclopropa[60]fullerene complexes (η2-C60)M(μ-η1,η1-trans-Ph2PCHCH PPh2)2M(η2-C60) (1, M = Pt; 2, M = Pd) were prepared by reaction of C60 with M(dba)2 (dba = dibenzylideneacetone) and trans-1,1′-bis(diphenylphosphino)ethylene in 82% and 92% yield, whereas reaction of C60 with Pd(dba)2 and trans-dppet followed by treatment with C60 and Pt2(dba)3 gave rise to the heterodinuclear complex (η2-C60) Pd(μ-η1,η1-trans-Ph2PCHCH PPh2)2Pt(η2-C60) (3) in 65% yield. Mechanistic study showed that these reactions involve the intermediates of monometallacyclopropa[60]fullerene diphosphine ligands (η2-C60)M(η1-trans-Ph2PCHCHPPh2)2 (4, M = Pt; 5, M = Pd). All the mono- and bismetallacyclopropa[60]fullerene complexes 1-5 have been fully characterized by elemental analysis and spectroscopy, as well as for 2 by X-ray crystallography. 相似文献
19.
Study of the factors determining the outcome of cycloaddition of isocyanurato-substituted azides to [60]fullerene 总被引:2,自引:0,他引:2
Sinyashin O. G. Romanova I. P. Yusupova G. G. Nafikova A. A. Kovalenko V. I. Azancheev N. M. Fattakhov S. G. Reznik V. S. 《Russian Chemical Bulletin》2001,50(11):2162-2171
The final outcome of cycloaddition of isocyanuratoalkyl azides to C60 depends on the temperature, the thermal stability of azides, the substituents in the isocyanurate ring, and the number of methylene groups in the alkyl radical. The thermal transformations of the monoadducts obtained were studied. 相似文献