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1.
Guobing Zhang Yingying Fu Qing Zhang Zhiyuan Xie 《Macromolecular chemistry and physics.》2010,211(24):2596-2601
Two new donor/acceptor copolymers PBDTPhBT1 and PBDTPhBT2 with alternating benzodithiophene ( BDT ) and bisthiophene‐phthalimide ( PhBT ) units were synthesized by Stille coupling reaction. The copolymers showed identical optical bandgaps of 1.98 eV. The HOMO energy levels are ?5.35 and ?5.32 eV for PBDTPhBT1 and PBDTPhBT2 , respectively. The bulk heterojunction solar cell devices based on these copolymers as donors and PC71BM as acceptor displayed high open‐circuit voltages of 0.90–0.93 V and achieved power conversion efficiency of 1.54% under the illumination of AM 1.5, 100 mW · cm?2.
2.
Mingliang Sun Qiaoli Niu Bin Du Junbiao Peng Wei Yang Yong Cao 《Macromolecular chemistry and physics.》2007,208(9):988-993
Fluorene‐based single‐chain copolymers with a white light emitter consisting of a blue and an orange chromophore have been synthesized and their photophysical and electroluminescent properties are investigated. The experimental results suggest that only a relatively small fraction of the orange‐emitting units incorporated into the fluorene is needed to achieve efficient white light emission by controlled incomplete energy transfer. A device from a copolymer with 0.02% DDQ content showed the highest external quantum efficiency of 2.64% with a luminance efficiency of 4.06 cd · A?1 with CIE coordinates (0.28, 0.24). The EL emissions are extremely stable over a wide range of current densities.
3.
Segmented block copolymers were synthesized using monodisperse diaramide (TΦT) as hard segments and PTMO with a molecular weight of 2 900 g · mol?1 as soft segments. The aramide: PTMO segment ratio was increased from 1:1 to 2:1 thereby changing the structure from a high molecular weight multi‐block copolymer to a low molecular weight end‐block copolymer. The thermal and thermal‐mechanical properties were studied by DSC and DMA. Also studied were the tensile and the elastic properties as well as the melt rheological behavior as a function of frequency. The crystallinity of aramide in the end‐block copolymers was found to be higher than in the multi‐block copolymer.
4.
Summary: Cylindrical brushes with poly(L ‐lysine) and poly(L ‐glutamate) side chains were prepared by “grafting through” and “grafting from” techniques. Grafting from is shown to be more successful for the synthesis of cylindrical brushes with high molar mass main and side chains.
5.
Derya Baran Abidin Balan Beatriz‐Meana Esteban Helmut Neugebauer Niyazi Serdar Sariciftci Levent Toppare 《Macromolecular chemistry and physics.》2010,211(24):2602-2610
D‐A‐D‐type polymers are of high interest in the field of photovoltaics and electrochromism. In this study we report the synthesis and electrochemical properties of PPyBT along with its photophysical properties and photovoltaic performance. PPyBT is soluble in common organic solvents and both n‐ and p‐type dopable, which is a desired property for conjugated polymers. During electrochemistry studies, the onset potentials of the polymer were determined as +0.2 V for oxidation and ?1.4 V for reduction. Using these values, HOMO and LUMO energy levels were calculated. The photovoltaic properties of PPyBT were also studied. PL studies showed that there is a charge transfer between PPyBT (donor) and PCBM (acceptor).
6.
Summary: Stabilized nanoparticles functionalized with carboxy groups were synthesized directly from dextran and acrylic acid (AA), without using any organic solvent and surfactant. The composition and morphology of these dextran‐based nanoparticles, as well as the mechanism of this one‐pot synthesis, were also investigated in this paper. This approach is anticipated to be applicable to various water‐soluble polysaccharides to fabricate nanoparticles facilely.
7.
Shailendra Singh Solanky Irne Campistron Albert Laguerre Jean‐Franois Pilard 《Macromolecular chemistry and physics.》2005,206(10):1057-1063
Summary: Degradation studies of cis‐1,4‐polyisoprene were carried out using first and second generation Grubbs catalysts to achieve end‐functionalized acetoxy oligomers in both an organic solvent and a latex phase at room temperature. Well‐defined acetoxy telechelic polyisoprene structures were obtained in a selective manner with a range of from 10 000 to 30 000, with a polydispersity index of around 2.5.
8.
Summary: This paper describes the synthesis of carboxyl‐functionalized polystyrene/silica (PS/SiO2) composite nanoparticles with various contents of poly(methacrylic acid) (PMAA) on the surface by post‐addition of methacrylic acid (MAA) via emulsion polymerization. High yields and binding efficiencies (around 90%) are achieved by an optimal procedure mainly involving the appropriate addition of MAA and amounts of surfactant and silica. The kinetics investigated indicates that the polymerization follows a mechanism different than that found in some earlier studies. The amount of grafted PMAA was determined by titration and FT‐IR, and altered in a wide range (1–40 wt.‐% to PS). Transmission electron microscopy (TEM) photographs show that the composite nanoparticles are about 60 nm in spherical shape and have a multi‐layered core‐shell structure with a cluster of primary silica beads as the core and PMAA as the outmost shell. There are approximately 4 to 21 primary silica beads in one composite nanoparticle, depending on the amount of silica added.
9.
Alberto Bolognesi Chiara Botta Anita Andicsova Umberto Giovanella Sergey Arnautov Jrme Charmet Edith Laux Herbert Keppner 《Macromolecular chemistry and physics.》2009,210(23):2052-2057
A series of substituted fluorenes with vinyl groups as reactive sites were synthesized and characterized. Fluorene‐based polymers with vinyl groups as end chains and side chains functionalities were also prepared. In both cases, successful preparation of functionalized Parylene C films (modylayers) was achieved. The set of spectral methods used has allowed us to conclude that such functionalization is based on the chemical reaction of double bonds with xylylene radicals during deposition process. Parylene C films chemically modified with specially synthesized polyfluorenes showed PL quantum efficiency comparable with neat polyfluorenes.
10.
Montserrat Fortuny Christian Graillat Timothy F. McKenna 《Macromolecular chemistry and physics.》2004,205(10):1309-1319
Summary: A new method for the measurement of monomer partitioning for emulsion polymerisation is presented. The method is based on measuring the partition coefficients for films cast from different latexes. Its validity was demonstrated for methyl methacrylate (MMA) and butyl acrylate (BA), as well as for mixtures of these two species, by comparing the data to model predictions using literature data. The model predictions and experimental results agreed quite well for MMA, but less so for BA due to its extremely low water solubility.
11.
Tilmann Ruhl Peter Spahn Holger Winkler Goetz P. Hellmann 《Macromolecular chemistry and physics.》2004,205(10):1385-1393
Summary: In previous papers, a novel melt process was reported for the preparation of colloidal crystals exhibiting the crystalline structure of opals. Latex spheres with a hard, crosslinked core and a grafted‐on elastomeric shell flow at elevated temperatures under uniaxial compression much like other polymer melts. However, the spheres start crystallizing at the plates of the press, whereupon the crystalline order grows, layer by layer, into the flowing melt. In this report, the domain order of opal disks thus obtained is discussed, together with the phenomena of light reflection. The pattern of light reflected from the (220) plane of the fcc lattice reveals that, during compression, this lattice is oriented macroscopically by the radial melt flow so that each radial sector of the opal disk forms a crystalline monodomain.
12.
Sophie Monmoton Hervé Lefebvre France Costa‐Torro Alain Fradet 《Macromolecular chemistry and physics.》2008,209(23):2382-2389
3,5‐Bis(bromomethyl)pyridine hydrobromide and 3,5‐bis(bromobutyl)pyridine hydrobromide were synthesized from commercially available 3,5‐lutidine. The poly(N‐alkylation) of these monomers readily yielded new hyperbranched polyelectrolytes. The progress of reaction was followed by 1H NMR. A second‐order kinetic scheme fits the experimental data. Rate constants and activation parameters were determined, showing the higher reactivity of 3,5‐bis(bromomethyl)pyridine hydrobromide. This was explained by the electron‐attractive effect of pyridinium groups on the ? CH2Br end groups. The structures of the hyperbranched poly[3,5‐bis(alkylene)pyridinium]s were investigated by 1H and 13C NMR spectroscopy and a preliminary study of their properties is reported.
13.
Jianping Deng Weiguo Zhao Jianmin Wang Zhigang Zhang Wantai Yang 《Macromolecular chemistry and physics.》2007,208(2):218-223
Copolymerization reactions of two N‐propargylamides [ 1 : HC?CCH2NHCO(CH2)5CH3, 2 : (HC?CCH2NHCOC(CH3)3] were carried out with different monomer feed ratios. Compared with the two corresponding homopolymers, the series of resulting copolymers poly( 1 ‐co‐ 2 ) had a higher helix content. They also performed very differently in conformational transitions, either from random coil to helix or from helix to random coil, mainly depending on the composition of the copolymers. Synergic effects among the pendent groups played a significant role in the copolymer main chains adopting stable helices.
14.
Paolo Costa‐Bizzarri Massimiliano Lanzi Luisa Paganin Carlo Della‐Casa Franco Bertinelli Mauro Casalboni Felice Sarcinelli Alessia Quatela 《Macromolecular chemistry and physics.》2003,204(16):1982-1988
Functionalized second‐order nonlinear optical (NLO) thiophene copolymers were synthesized. Two elegant syntheses based on the post‐functionalization of polymeric precursors obtained by oxidative polymerization were developed, leading to copolymers that proved to be fully soluble in common organic solvents. The new materials were characterized by NMR, FT‐IR, and UV‐vis spectroscopies, gel permeation chromatography (GPC), and thermogravimetric analysis (TGA). Moreover, the NLO activity of the new materials, as determined by corona poling alignment and second harmonic generation (SHG) measurements, showed a good agreement between the second‐order NLO coefficient and the chromophore concentration.
15.
Afang Zhang Lijin Shu Zhishan Bo A. Dieter Schlüter 《Macromolecular chemistry and physics.》2003,204(2):328-339
This article divides the synthetic routes leading to dendronized polymers into two main categories (attach‐to and macromonomer) and compares their respective advantages and disadvantages. It gives a comprehensive overview on the kind of structures presently available and also spans the bridge between both polymers and molecular objects, decorated with only a few dendrons, and the structurally related, but less well defined polymers with hyperbranched side chains.
16.
Michal Wagner Anna
sterholm Sami‐Pekka Hirvonen Heikki Tenhu Ari Ivaska Carita Kvarnstrm 《Macromolecular chemistry and physics.》2011,212(15):1567-1574
Novel water dispersible poly(benzimidazobenzophenanthroline) polymers functionalized with poly(ethylene oxide) (BBL:PEO) have been investigated by cyclic voltammetry, in situ UV‐vis spectroscopy and atomic force microscopy. The cyclic voltammograms recorded during n‐doping indicate that the drop coated BBL:PEO films retain their properties despite functionalization. A small influence of the PEO side chains on redox properties of the investigated polymers was found, diminishing however after annealing. During spectroscopic experiments structural changes connected with polymer charging were observed (in accordance with a two electron transfer process). The functionalization of BBL with PEO side chains provided an easy processing method to obtain smooth and reproducible polymer films.
17.
Harald Hofmeier Stefan Schmatloch Daan Wouters Ulrich S. Schubert 《Macromolecular chemistry and physics.》2003,204(18):2197-2203
In the present contribution, we synthesized linear coordination polymers based on oligo(ethylene glycol)s as well as poly(ethylene glycol)s and terpyridine ruthenium(II) complexes. The reaction conditions, e.g., solvent, concentration, were varied to obtain well‐soluble, high molecular weight polymers. The resulting compounds were characterized by UV‐vis and NMR spectroscopy. The viscosity of the materials was also investigated with and without salt addition. Finally, the polymers were characterized with DSC and AFM. AFM revealed a lamellar morphology.
18.
Soo Whan Choi Oliver Kretschmann Helmut Ritter Marina Ragnoli Giancarlo Galli 《Macromolecular chemistry and physics.》2003,204(12):1475-1479
We report on the first examples of the free radical polymerization of a fluorinated 2‐vinylcyclopropane 1 and its copolymerization with an alkyl 2‐vinylcyclopropane 2 in aqueous solution via their host‐guest complexation with a random methylated β‐cyclodextrin (RAMEB) using a water‐soluble initiator (VA50). Upon polymerization, the dethreaded cyclodextrin remained in water solution, whereas the water‐insoluble polymer precipitated out and was isolated. The polymers prepared exhibited mesophase behavior over a wide range of temperature. Both Tg and Ti of the copolymers increased linearly with the amount of fluorinated co‐units.
19.
Summary: A dipolar filter pulse sequence combined with cross‐polarization‐MAS is applied to characterize the phase distribution, morphology, and spin diffusion within a high‐density polyethylene sample. A new method to obtain quantitative 13C NMR by combining cross‐polarization‐MAS and spin diffusion NMR is presented. The derived crystallinity is consistent with the corresponding crystallinity obtained by 1H NMR.
20.
Sindy Kayillo R. Andrew Shalliker Gary R. Dennis 《Macromolecular chemistry and physics.》2005,206(20):2013-2017
Summary: Deuterated compounds are generally considered to possess very similar properties to their protonated analogues. Reversed phase liquid chromatography (RPLC) was used to measure thermodynamic interactions between deuterated and protonated n‐butyl polystyrenes and a C18 stationary phase. Significant differences in enthalpies and entropies of interaction were observed for deuterated and protonated n‐butyl polystyrenes. This is very important because many techniques, such as small‐angle neutron scattering and neutron reflectivity, assume that the interaction of these molecules are identical.