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1.
Naiying Du Gilles P. Robertson Ingo Pinnau Sylvie Thomas Michael D. Guiver 《Macromolecular rapid communications》2009,30(8):584-588
A series of new copolymers with high molecular weight and low polydispersity, prepared from tetrahydroxydinaphthyl, tetrahydroxyspirobisindane, and tetrafluoroterephthalonitrile monomers, prevent efficient space packing of the stiff polymer chains and consequently show intrinsic microporosity. One copolymer, DNPIM‐33, has an excellent combination of properties with good film‐forming characteristics and gas transport performance, and exhibits higher selectivity than the corresponding spirobisindane‐based homopolymer PIM‐1 for gas pairs, such as O2/N2, with a corresponding small decrease in permeability. This work demonstrates that significant improvements in properties may be obtained through development of copolymers with intrinsic microporosity (CoPIMs) that extends the spectrum of high‐molecular‐weight ladder structures of poly(dibenzodioxane)s.
2.
Summary: The separation of H2/CO2 is technologically important to produce the next generation fuel source, hydrogen, from synthesis gas. However, the separation efficiency achieved by polymeric membranes is usually very low because of both unfavourable diffusivity selectivity and solubility selectivity between H2 and CO2. A series of novel diamino‐modified polyimides has been discovered to enhance the separation capability of polyimide membranes especially for H2 and CO2 separation. Both pure gas and mixed gas tests have been conducted. The ideal H2/CO2 selectivity in pure gas tests is 101, which is far superior to other polymeric membranes and is well above the Robeson's upper‐bound curve. Mixed gas tests show an ideal selectivity of 42 for the propane‐1,3‐diamine‐modified polyimide. The lower selectivity is a result of the sorption competition between H2 and the highly condensable CO2 molecules. However, both pure gas and mixed gas data are better than other polymeric membranes and above the Robeson's upper‐bound curve. It is evident that the proposed modification methods can alter the physicochemical structure of polyimide membranes with superior separation performance for H2 and CO2 separation.
3.
Ken Kawagishi Hiromu Saito Hidemitsu Furukawa Kazuyuki Horie 《Macromolecular rapid communications》2007,28(1):96-100
We report novel nanoporous polyimides formed from jungle‐gym‐type rigid polyimide gels by supercritical CO2 drying. By virtue of supercritical CO2 drying to avoid the collapse of nanostructure, porosity above 90 vol.‐% was achieved. We found a rich variety of nanoporous structures in the range of 50–800 nm such as crisp fragments, minute network, and highly‐connected beads. These characteristic structures were formed by the competitive progress of liquid‐liquid phase separation and crystallization induced due to the two chemical reactions of end‐crosslinking and thermal imidization during gelation.
4.
Courtney A. Pfluger Rebecca L. Carrier Bing Sun Katherine S. Ziemer Daniel D. Burkey 《Macromolecular rapid communications》2009,30(2):126-132
Plasma Enhanced Chemical Vapor Deposition (PECVD) of poly‐2‐hydroxyethyl methacrylate (pHEMA) biocompatible, biodegradable polymer films were produced alone and cross‐linked with ethylene glycol diacrylate (EGDA). Degree of cross‐linking was controlled via manipulation of the EGDA flow rate, which influenced the amount of swelling and the extent of degradation of the films in an aqueous solution over time. Noncross‐linked pHEMA films swelled 10% more than cross‐linked films after 24 h of incubation in an aqueous environment. Increasing degree of film cross‐linking decreased degradation over time. Thus, PECVD pHEMA films with variable cross‐linking properties enable tuning of gel formation and degradation properties, making these films useful in a variety of biologically significant applications.
5.
Muhammet U. Kahveci M. Atilla Tasdelen Yusuf Yagci 《Macromolecular rapid communications》2008,29(3):202-206
This study describes the use of diphenyliodonium salts with highly nucleophilic counter anions to photoinitiate the cationic cross‐linking of divinyl ethers. Both direct and indirect initiating modes are used. In the direct acting system, only a diphenyliodonium salt with a highly nucleophilic counter anion and a zinc halide are employed as initiator and activator, respectively. In the indirect systems, in addition to direct system components, photosensitive additives such as anthrecene, perylene, 2,2‐dimethoxy‐2‐phenyl acetophenone, benzophenone, and thioxanthone, which absorb the energy of the incident light and activate the iodonium salt, are used to initiate polymerization. All systems employed in this study initiated quite vigorous polymerizations.
6.
Stefan Schmatloch Monica Fernndez Gonzlez Ulrich S. Schubert 《Macromolecular rapid communications》2002,23(16):957-961
Bis(2,2′:6′,2″‐terpyrid‐4′‐yl) diethylene glycol was synthesized as a monomer unit and further utilized for polymerization with FeCl2 in order to form water‐soluble coordination polymers. Viscosity measurements and film‐forming properties indicate the formation of linear coordination polymers or larger ring structures. The terpyridine/iron(II) complexes are stable up to temperatures of 210 °C, but can be uncomplexed by the addition of an excess of a strong competitive ligand (HEDTA) under mild conditions.
7.
Naiying Du Renyu Tian Junbiao Peng Qunbo Mei Mangeng Lu 《Macromolecular rapid communications》2006,27(6):412-417
Summary: Homopolymers and a series of copolymers with tris‐8‐hydroxyquinoline aluminum (Alq3) as the cross‐links are synthesized. All these polymers show improved electroluminescence (EL) efficiency over their previously reported counterparts. Among them, the copolymers containing Alq3 and carbazole groups show higher EL efficiency than that of the homopolymers. We also demonstrate the feasibility of generating patterns using the homopolymers via photopolymerization. The cross‐linked nature, selectivity of patterning, high thermal stability, and EL efficiency might render these polymers a promising material in fabricating large‐scaled multilayered sub‐pixellation organic light‐emitting diodes (OLEDs).
8.
Summary: Single polyelectrolyte component microcapsules and multilayers, exemplified by poly(allylamine hydrochloride) (PAH), have been prepared using a method of glutaraldehyde (GA)‐mediated covalent layer‐by‐layer (LbL) assembly. The GA cross‐linking of the adsorbed PAH results in surfaces covered by reactive aldehyde groups, which can then react with PAH to result in another layer of covalently linked PAH. The repeated assembly of single polyelectrolyte in an LbL manner can be thus achieved. The PAH multilayers can grow linearly along with the layer number, and their thickness can be controlled at the nanometer scale, as verified by UV‐vis absorption spectrometry and ellipsometry. Single polyelectrolyte microcapsules are obtained after removal of the template cores at low pH. The morphology and integrity are confirmed by scanning force microscopy and confocal laser scanning microscopy.
9.
Elin Persson Jutemar Shogo Takamuku Patric Jannasch 《Macromolecular rapid communications》2010,31(15):1348-1353
The lithium salt of 2,6‐difluoro‐2′‐sulfobenzophenone was conveniently synthesized in one‐pot by reacting 2,6‐difluorophenyllithium with 2‐sulfobenzoic acid cyclic anhydride in THF at −70 °C whereafter the product crystallized out of solution. A poly(arylene ether) and a poly(arylene sulfide) were prepared by polycondensation reactions to demonstrate the reactivity and efficacy of this new monomer to produce sulfonated high‐molecular weight aromatic polymers for fuel cell proton‐exchange membranes. This work demonstrated that organolithium chemistry may offer versatile and straightforward pathways to new functional monomers with fluorine atoms activated for nucleophilic aromatic substitution reactions.
10.
Reactions between the ethylene groups in the backbone of conjugated polymers under UV illumination and heat treatment result in the cross‐linking of the main polymer chains. The cross‐linking leads to two simultaneous results in the polymer: excellent solvent resistance and increased bandgap. Using this reaction, three‐color polymer light‐emitting diodes (PLEDs) with a multi‐layer structure can be easily realized by a dry photo‐pattern in an active‐gas‐free environment. Multi‐layer blue devices with dramatically enhanced efficiency can also be achieved conveniently.
11.
Zhaoyuan Liu Ying Zhu Liang Wang Chunmei Ding Nü Wang Meixiang Wan Lei Jiang 《Macromolecular rapid communications》2011,32(6):512-517
Polyaniline (PANI) microtubes with a hexagonal cross‐section are successfully synthesized by a self‐assembly process in the presence of 8‐hydroxyquinoline‐5‐sulfonic acid (HQS) as a dopant and FeCl3 as an oxidant. The wall thickness of the PANI/HQS microtubes can be adjusted by the content of the oxidant. It is proposed that the aniline/HQS salts serve as a hard template for the formation of the hexagonal‐cross‐section microtubes. Moreover, PANI/HQS microtubes combined with ZnSO4 show pH‐dependent fluorescence. PANI hexagonal‐cross‐section microtubes combined with a pH‐sensitive fluorescence may promise potential applications in fields such as chemical sensors and confined reaction vessels.
12.
Kai Zhang Bernd Tieke Filipe Vilela Peter J. Skabara 《Macromolecular rapid communications》2011,32(11):825-830
π‐Conjugated microporous networks have been prepared from the tetraarylated diketopyrrolo[3,4‐c]pyrrole unit as a tetrafunctional building block. The reactions are carried out using microwave‐assisted Yamamoto or Sonogashira cross‐coupling. Red insoluble powders are obtained, showing intense fluorescence. The polymer networks exhibit a high gas storage capability, with BET surface areas up to about 500 m2 · g−1.
13.
Wei Su Yanhua Luo Qing Yan Si Wu Kuo Han Qijin Zhang Yongqiang Gu Yinmei Li 《Macromolecular rapid communications》2007,28(11):1251-1256
Poly(N‐isopropylacrylamide)‐block‐poly{6‐[4‐(4‐methylphenyl‐azo) phenoxy] hexylacrylate} (PNIPAM‐b‐PAzoM) was synthesized by successive reversible addition‐fragmentation chain transfer (RAFT) polymerization. In H2O/THF mixture, amphiphilic PNIPAM‐b‐PAzoM self‐assembles into giant micro‐vesicles. Upon irradiation of light at 365 nm, fusion of the vesicles was observed directly under an optical microscope. The real‐time fusion process is presented and the derivation is preliminarily due to the perturbation by the photoinduced trans‐to‐cis isomerization of azobenzene units in the vesicles.
14.
Xianghui Chen Shanlin Qiao Zhengkun Du Yuanhang Zhou Renqiang Yang 《Macromolecular rapid communications》2013,34(14):1181-1185
A novel kind of functional organic microporous polymer is designed by introducing polar organic groups (P=O and P=S) and electron‐rich heterocyclic into the framework to obtain high carbon dioxide capture capacity. The estimated Brunauer–Emmett–Teller (BET) surface areas of these polymers are about 600 m2 g−1 and the highest CO2 uptake is 2.26 mmol g−1 (1.0 bar/273 K). Interestingly, the polymer containing P=O groups shows greater CO2 capture capacity than that containing P=S groups at the same temperature. In addition, these polymers show high isosteric heats of CO2 adsorption (28.6 kJ mol−1), which can be competitive with some nitrogen‐rich networks. Therefore, these microporous polymers are promising candidates for carbon dioxide capture.
15.
Xuan Zhang Zhaoxia Hu Linqiang Luo Shanshan Chen Jianmei Liu Shouwen Chen Lianjun Wang 《Macromolecular rapid communications》2011,32(14):1108-1113
Novel poly(arylene ether ketone) polymers with fluorophenyl pendants and phenoxide‐terminated wholly sulfonated poly(arylene ether sulfone) oligomers are prepared via Ni(0)‐catalyzed and nucleophilic polymerization, respectively, and subsequently used as starting materials to obtain graft‐crosslinked membranes as polymer electrolyte membranes. The phenoxide‐terminated sulfonated moieties are introduced as hydrophilic parts as well as crosslinking units. The chemical structure and morphology of the obtained membranes are confirmed by 1H NMR and tapping‐mode AFM. The properties required for fuel cell applications, including water uptake and dimensional change, as well as proton conductivity, are investigated. AFM results show a clear nanoscale phase‐separation microstructure of the obtained membranes. The membranes show good dimensional stability and reasonably high proton conductivities under 30–90% relative humidity. The anisotropic proton conductivity ratios (σ⟂/||) of the membranes in water are in the range 0.65–0.92, and increase with an increase in hydrophilic block length. The results indicate that the graft‐crosslinked membranes are promising candidates for applications as polymer electrolyte membranes.
16.
Huiping Bi Shouwen Chen Xinbing Chen Kangcheng Chen Nobutaka Endo Mitsuru Higa Kenichi Okamoto Lianjun Wang 《Macromolecular rapid communications》2009,30(21):1852-1856
Novel poly(2‐(3‐sulfo)benzoyl‐1,4‐phenylene)‐block‐polynaphthalimide (PSP‐b‐PI) copolymers were successfully synthesized by Ni(0)‐catalyzed copolymerization of 2,5‐dichloro‐3′‐sulfo‐benzophenone and dichloro‐terminated naphthalimide oligomer. The membranes exhibited a microphase‐separated structure and good hydrolytic stability at 130 °C. They showed a fairly strong anisotropy of membrane swelling with much smaller in‐plane swelling, but a rather weak anisotropy of proton conductivity. The membranes had a fairly high through‐plane conductivity in water and even under low relative humidity. The PSP‐b‐PI copolymer with an IEC of 1.5 meq · g−1 showed high PEFC performance due to the high through‐plane conductivity.
17.
Daisuke Nagai Akinori Suzuki Takaya Kuribayashi 《Macromolecular rapid communications》2011,32(4):404-410
Hydrogels were successfully synthesized utilizing CO2 as a gellant. A cross‐linking reaction of polyallylamine (PAA) with CO2 in the presence of 1,8‐Diazabicyclo[5,4,0]‐undec‐7‐ene (DBU) provided hydrogels bearing urea cross‐linking points and residual amino groups in the side chains. The obtained hydrogels absorbed CO2 at 25 °C and gave a maximum absorption four times larger than that of PAA aqueous solution and 2.8 times larger than that of the most commonly used absorbent, monoethanolamine. The PAA hydrogels desorbed the absorbed CO2 completely under a N2 atmosphere at 120 °C, and could be repeatedly recycled without loss of efficiency, indicating their potential application as recyclable CO2 absorption materials.
18.
Jing Fung Tan Anton Blencowe Tor Kit Goh Greg G. Qiao 《Macromolecular rapid communications》2010,31(3):305-309
This communication details the successful synthesis of low polydispersity core cross‐linked star (CCS) polymers via DPE‐mediated polymerisation. We demonstrate the ability to produce poly(methyl methacrylate) and poly(acrylonitrile) CCS polymers that are currently inaccessible via the two most common non‐metal‐based controlled radical polymerisation techniques (NMP and RAFT polymerisations).
19.
Xiu‐Zhen Wei Bao‐Ku Zhu Ling Xiao You‐Yi Xu Kurt E. Geckeler 《Macromolecular rapid communications》2005,26(15):1224-1227
Summary: Novel hyperbranched poly(amine‐ester) (HPAE) cross‐linked films were prepared by cross‐linking the terminal hydroxyl groups of HPAE using glutaraldehyde (GA). Atom force microscope and scanning electron microscope revealed their smooth surfaces, dense and homogenous matrices. Property characterizations indicated that these cross‐linked films had good hydrophilicity, relative low protein adsorption, and high tensile strength. Also, their swelling behavior varied with the solvent.
20.
Naiying Du Jingshe Song Gilles P. Robertson Ingo Pinnau Michael D. Guiver 《Macromolecular rapid communications》2008,29(10):783-788
A high molecular weight ladder polymer based on 5,5′,6,6′‐tetrahydroxy‐3,3,3′,3′‐tetramethylspirobisindane and 1,4‐dicyanotetraflurobenzene has been synthesized by polycondensation under high‐intensity mixing conditions at about 155 °C and cyclic‐free products were obtained in high yield with low molecular weight distribution (1.7–2.3). The reaction could be completed within a few minutes. The polymer properties were characterized by GPC, 1H NMR, 13C NMR, F NMR, FT‐IR, and MALDI‐TOF MS. In addition, the mechanical properties, apparent surface areas and gas permeability are also reported. This procedure can also be used for the synthesis of other ladder polymers by irreversible polycondensations of tetraphenols with activated tetrafluoro aromatics.