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1.
Akshay Kokil Christian Huber Walter R. Caseri Christoph Weder 《Macromolecular chemistry and physics.》2003,204(1):40-45
The present paper reports the synthesis of π‐conjugated organometallic polymer networks based on poly[2,5‐dioctyloxy‐1,4‐diethynyl‐phenylene‐alt‐2,5,‐bis(2′‐ethylhexyloxy)‐1,4‐phenylene] (EHO‐OPPE), a soluble poly(p‐phenylene ethynylene) (PPE) derivative. The ethynylene moieties of the polymer coordinate to Pt0 centers, which act as conjugated cross‐links. These materials are readily accessible through ligand‐exchange reactions between the linear PPE and Pt(styrene)3. The in‐situ NMR investigation of model reactions of Pt(styrene)3 with diphenylacetylene (DPA) has shown that the ethynylene moieties comprised in the PPE readily coordinate to Pt0 centers under release of the relatively weakly‐bound styrene ligands. Spin‐coating has resulted in cross‐linked films of good optical quality. We also have been able to produce PPE‐Pt‐gels with high solvent content (> 95 wt.‐%). As expected, the coordination of Pt markedly influences the photophysical characteristics of the PPE. The photoluminescence is efficiently quenched, and the absorption maximum in the visible regime experiences a hypsochromic shift.
2.
Anthony J. Pasquale Ann R. Fornof Timothy E. Long 《Macromolecular chemistry and physics.》2004,205(5):621-627
Summary: Several norbornene (Nb) derivatives were synthesized by facile Diels‐Alder cycloaddition reactions of cyclopentadiene with α‐olefins containing electron‐withdrawing groups such as nitrile (CN), phosphonate, and ester. The Diels‐Alder adducts were subsequently copolymerized with maleic anhydride (MAH) using free radical polymerization conditions previously determined for MAH/Nb copolymerizations. Further functionality was introduced into the copolymers through acid‐catalyzed hydrolysis of poly(Nb‐alt‐MAH) and poly(NbCN‐alt‐MAH) copolymers. FTIR confirmed hydrolysis of the anhydrides to carboxylic acid‐functionalities and indicated no appreciable hydrolysis of the nitrile functionality. Observed copolymerization rates (kobs) were measured using in situ FTIR. A dramatic decrease in the rate of copolymerization was observed for the Nb derivatives that contained a strong electron‐withdrawing functionality. This observation suggested a significant electronic influence on the free radical copolymerization rate with maleic anhydride due to the electron‐withdrawing nature of the Nb substituents.
3.
Antonio Carella Fabio Borbone Ugo Caruso Roberto Centore Antonio Roviello Alberto Barsella Alessia Quatela 《Macromolecular chemistry and physics.》2007,208(17):1900-1907
New polyurethanes containing Y‐shaped chromophores, symmetrical derivatives of 4‐(dicyanomethylene)‐2‐methyl‐6‐[p‐(dimethylamino)styryl]‐4H‐pyran, have been prepared. The polymers show high glass transition temperatures (Tg) and a good thermal stability. SHG measurements on poled polymer films of the synthesized polymers have been carried out and a maximum d33 of 15 pm · V?1 has been found at 1 368 nm fundamental wavelength. Time stability measurements on the most active polymer have shown that after the initial fast relaxation, the d33 value remains constant at 80 °C for 60 d.
4.
Kwang‐Hoi Lee Ho‐Jin Lee Kazuhide Morino Atsushi Sudo Takeshi Endo 《Macromolecular chemistry and physics.》2010,211(23):2490-2496
π‐Conjugated polymers composed of dialkoxybenzo[1,2‐b:4,5‐b′]dithiophene and thiophenes bearing cyano‐alkoxycarbonylethenyl [? CH?C(CO2R)CN] and bis(alkoxycarbonyl)ethenyl groups [? CH?C(CO2R)2] were prepared. The optical properties of the obtained polymers were investigated by UV‐vis and photoluminescence spectroscopy to demonstrate that the absorption maxima of the polymers were tunable by varying the substituent of thiophene unit. The photoluminescence wavelengths and intensities of the polymer in solution were significantly dependent on the polymer side chain. The HOMO energy level of the polymer was lowered by up to ?5.51 eV by introducing electron‐deficient cyano groups. Polymer solar cells based on the new polymers were fabricated to achieve a PCE of 1.90%.
5.
Hiroshi Ogawa Elke Stibal‐Fischer Heino Finkelmann 《Macromolecular chemistry and physics.》2004,205(5):593-599
Summary: Biaxial side‐on cholesteric copolysiloxanes with laterally attached mesogenic groups were investigated in mixtures with a low molar mass liquid crystal. While mixtures with a low concentration of the polymer exhibit the conventional fingerprint texture, for concentrations above about 60 mol‐% characteristic irregularities appear in the cholesteric structure that are obviously due to phase biaxiality. Besides the absence of pseudo‐isotropic lines, irregular patterns perpendicular to the helix axis emerge and the periodic distance of regions with similar optical properties along the helix axis is strongly disturbed. This suggests that the photonic band gap width of a uniaxial cholesteric phase becomes strongly affected when a phase transformation into a biaxial cholesteric phase occurs.
6.
Radmila Tomovska Markéta Urbanová Jan Šubrt Jaroslav Boháček Josef Pola 《Macromolecular chemistry and physics.》2007,208(16):1782-1788
ArF laser irradiation of gaseous mixtures of carbon disulfide and silane allows efficient deposition of Si? S bond‐containing poly(thiacarbosilanes) incorporating SiS bodies. These SiS/poly(thiacarbosilane) composites are the first example of silicon sulfide/polymer composites. Composite formation is analyzed by GC/MS analysis of volatile products and the structure of the composite as determined by electron microscopy and FT‐IR spectra. The composites undergo reaction with air moisture and methanol vapor, evolve H2S and evolve to nano‐sized poly(thiacarbosiloxane)s and poly(methoxythiacarbosiloxane)s.
7.
Polythiophene‐graft‐poly(methyl methacrylate) brushes are synthesized by ATRP. They form miscible blends with poly(vinylidene fluoride) (PVDF) due to specific interactions between the >C?O groups of PT‐g‐PMMA with the >CF2 groups of PVDF. PT‐g‐PMMA remains in the interlamellar, interfibrillar and interspherulitic regions of the PVDF crystals at both laterally and longitudinally aggregated states. In the blends both PVDF and PT‐g‐PMMA brushes have nanometer sizes, producing nanostructured polymer blends. The PL intensity can be tuned by varying the PT‐g‐PMMA concentration, and the blend exhibits good dc conductivity with a percolation threshold at 10 wt.‐% PT‐g‐PMMA. Conductivity data indicate a conformational transition of PT‐g‐PMMA chains with increasing temperature.
8.
The mechanism of ring‐opening polymerization of some lactones and lactide initiated by lanthanum isopropoxide has been comprehensively investigated. NMR and viscosity analyses demonstrated that three active polymer chains grow per lanthanum atom and that, depending on the coordinating ability of the monomer, propagation proceeds on aggregated or unaggregated active species. It is also demonstrated that inter‐ and intramolecular side reactions are limited and that lanthanum‐based initiator selectivity in ring‐opening polymerization is analogous to that of aluminum ones.
9.
Volker Brger Olga Kuliskovska Kati G.‐Hubmann Joachim Stumpe Marco Huber Henning Menzel 《Macromolecular chemistry and physics.》2005,206(15):1488-1496
Summary: The influence of the azobenzene concentration on the photo‐induced surface relief grating (SRG) formation in polymer films was investigated. Two series of polymers with 4‐alkoxy‐4′‐cyanoazobenzene side groups were synthesized. In series A, the degree of substitution was varied, while in series B, azobenzene and biphenyl groups were introduced in varying composition, but the concentration of non‐reacted HEMA‐groups was kept constant. Photo‐induction of the dichroism and the SRG was studied as function of the azobenzene concentration. An optimum was found for the SRG formation (76%), while the highest dichroism was induced at the lowest azobenzene concentration of 20%. The restriction of rotational and translational molecular motions observed at higher azobenzene concentration was explained by π‐π stacking of the azobenzene moieties and interaction of unreacted HEMA groups.
10.
Summary: We report on the synthesis of polyacrylamides that were prepared by the reaction of a reactive ester polymer with a mesogen‐containing secondary amine and N‐methylpiperazine. As the polymers do not form hydrogen bonds near the amide groups, their mobility is significantly higher than that of poly(N‐monoalkylacrylamides). The initially nonionic polymer shows no liquid‐crystalline behavior in bulk and in mixture with ethylene glycol. This is due to the low polarity difference between the different side chains. The polarity difference can be increased by protonation or quarternization of the tertiary amino groups, and liquid‐crystalline behavior is observed. The self‐assembly multilayer build‐up of the polymer with quarternized amino groups, and an anionic polyelectrolyte proceeds regularly.
11.
Summary: In this article we describe the synthesis of various monomers modified with triphenyl‐1,3,5‐triazine side groups as electron transport moieties. By nitroxide‐mediated polymerization with a TEMPO unimer it was possible to obtain polymers with a narrow polydispersity. Furthermore, by living radical polymerization block copolymers were obtained from these monomers. Therefore, microphase separated structures are accessible which possess hole conducting moieties in one phase and electron conducting moieties in the other phase.
12.
Wai‐Yeung Wong Gui‐Jiang Zhou Ze He Kai‐Yin Cheung Alan Man‐Ching Ng Aleksandra B. Djurišić Wai‐Kin Chan 《Macromolecular chemistry and physics.》2008,209(13):1319-1332
The synthesis, thermal, and photoluminescence properties of novel platinum metallopolyynes of bithiazole derivatives trans‐[? Pt(PR3)2‐C≡C‐Ar‐C≡C? ]n (Ar = 4,4′‐dibutyl‐2,2′‐bithiazole‐5,5′‐diyl P1 ; 4,4′‐dinonyl‐2,2′‐bithiazole‐5,5′‐diyl P2 ) and their molecular model complexes are described. The structural properties of the dinuclear model compound for P1 have been examined by X‐ray crystallography. In view of the electron‐donating and electron‐withdrawing nature of the thiazole rings in the main chain, a strong π‐conjugated system that features unique donor–acceptor interactions is created, which results in optical bandgaps of 2.40 eV. The optical gap of the polymer is notably reduced as compared to that for the more electron‐rich bithienyl analogue. Multi‐layer polymer light‐emitting diodes have been fabricated with the metallopolymer as the emitting layer, which give a green light color with the Commission Internationale de L'Eclairage (CIE) chromaticity coordinates of (0.26, 0.58) at 8 V.
13.
Erjun Zhou Junzi Cong Keisuke Tajima Chunhe Yang Kazuhito Hashimoto 《Macromolecular chemistry and physics.》2011,212(3):305-310
A novel donor–acceptor (D–A) type alternating copolymer based on dithieno[3,2‐b:2′,3′‐d]pyrrole (DTP) and thieno[3,4‐c]pyrrole‐4,6‐dione (TPD) was synthesized. The polymer has a broad absorption spectrum in the range of 350–810 nm. The energy levels of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) of the copolymer were ?5.11 and ?3.63 eV, respectively, as determined by cyclic voltammetry. Bulk heterojunction type polymer solar cells based on PDTP‐TPD and PC70BM, showed power conversion efficiency (PCE) up to 1.6% with an open‐circuit voltage of VOC = 0.66 V, a short‐circuit current of ISC = 4.98 mA · cm?2, and a fill factor of FF = 0.50. The VOC of 0.66 V is the highest value among DTP‐based photovoltaic polymers.
14.
Gilles Olive Xavier Rozanska Wilfred Smulders Alain Jacques Anton German 《Macromolecular chemistry and physics.》2002,203(12):1790-1796
The control of the radical polymerization of styrene by 2,2,15,15‐tetramethyl‐1‐aza‐4,7,10,13‐tetraoxacyclopentadecan‐1‐oxyl is reported here in bulk at 90 °C, 120 °C and in miniemulsion. Similarly, the control by its sodium complex is reported in bulk at 90 °C.
15.
Hung‐Min Shih Cheng‐Jui Lin Shin‐Rong Tseng Chih‐Hung Lin Chain‐Shu Hsu 《Macromolecular chemistry and physics.》2011,212(11):1100-1108
A series of anthracene‐based conjugated copolymers containing 9,10‐bis(6‐bromonaphthalen‐2‐yl)‐2‐tert‐butylanthracene (BNA) and 2,7‐diphenyl substituted fluorene (DPPF) moieties are prepared via a palladium‐catalyzed Suzuki polymerization. All of the synthesized polymers emit blue light at around 450 nm and show good thermal and color stability. Their electroluminescence spectra remain unchanged at high driving voltage. The double‐layer polymer light‐emitting diode (PLED) fabricated with ITO/PEDOT:PSS/DPPFBNA3/CsF/Al, produces a maximum brightness of 1 650 cd · m?2 and has a luminance efficiency of 0.39 cd · A?1. The ITO/PEDOT:PSS/TFB/DPPFBNA3/CsF/Al multilayer PLED, incorporating a TFB layer to facilitate hole transportation, produces a maximum brightness of 5 371 cd · m?2 and a luminance efficiency of 1.18 cd · A?1.
16.
Cyril Boyer Gilles Boutevin Jean‐Jacques Robin Bernard Boutevin 《Macromolecular chemistry and physics.》2004,205(5):645-655
Summary: The telomerization of 2‐(dimethylamino)ethyl methacrylate (DMAEMA) with 2‐mercaptoethanol in acetonitrile shows that the telogen can react with the monomer by nucleophilic addition. It is to say that the tertiary amino group leads to nucleophilic addition rather than telomerization. The oligomers thus obtained were functionalized with 1‐(isopropenylphenyl)‐1,1‐dimethylmethyl isocyanate (TMI) in anhydrous toluene to afford macromonomers. These macromonomers were copolymerized with styrene and the r1, r2 ratio was determined according to Jaacks and Macret's methods. It was thereby demonstrated that the r1 value for this type of monomer is close to zero.
17.
Aurica Farcas Nathalie Jarroux Indrajit Ghosh Philippe Guégan Werner M. Nau Valeria Harabagiu 《Macromolecular chemistry and physics.》2009,210(17):1440-1449
The paper reports on the preparation of a new 2‐rotaxane monomer through an acid coupling reaction between 1‐pyrenecarboxaldehyde and α‐CD/3,5‐diamino‐1,2,4‐triazole inclusion complex. Pyrenyl groups are large enough to provide a blocking effect toward cyclodextrin de‐threading. The oxidative C? C coupling of 2‐rotaxane in the presence of RuCl3 catalyst afforded conjugated azomethine polyrotaxanes. The expected modifications of the solubility, morphology, film forming ability for rotaxane polymer were proved. As shown by fluorescence and UV‐vis spectroscopy, a material with optical properties appropriate for use in photonics was obtained.
18.
Summary: Chemical shift trends in the methylene and α substituent regions of 13C NMR spectra of vinyl polymers have been analyzed in terms of a three‐state rotational isomeric states (RIS) model and the γ‐gauche effect. In this framework, it has been demonstrated that the three sequencing rules observed for poly(propylene) can also be expected to work for many other vinyl polymers. The first two rules, justified in terms of the conformational perturbability of stereosequences, turn out to be respected by a considerable number of NMR spectra. On the other hand, the same spectral data are in substantial disagreement with the third rule. An explanation is proposed for this breakdown.
19.
Aadil Elmoumni Ramon A. Gonzalez‐Ruiz E. Bryan Coughlin H. Henning Winter 《Macromolecular chemistry and physics.》2005,206(1):125-134
Summary: Two well‐characterized metallocene isotactic poly(propylene) (iPP) samples, one of high and one of low molecular weight, were blended together for studying the effects of a second component on quiescent and shear‐induced crystallization. A small amount of added high molecular weight (HMW) (up to 10 wt.‐%) polymer increases the quiescent crystallization rate. This was observed as a decrease in characteristic halftime of transmitted light intensity. The crystallization halftime increases again when adding more than 10 wt.‐% of HMW polymer. The crystallization halftime of pre‐sheared samples decreases with increasing HMW fraction and is lowest for the HMW sample by itself. For the specific shearing conditions (γ = 600, Tx = 145 °C), wide‐angle X‐ray diffraction (WAXD) images show the presence of the gamma (γ) crystalline phase of iPP for samples containing 25 wt.‐% of HMW and higher. DSC thermograms demonstrated higher crystalline fractions with increasing HMW fraction in pre‐sheared samples.
20.
Denise Barbier‐Baudry Fanny Bonnet Alain Dormond Eric Finot Marc Visseaux 《Macromolecular chemistry and physics.》2002,203(9):1194-1200
A well‐controlled two‐step process, the polymerisation of isoprene or isoprene/hex‐1‐ene copolymerisation followed by ε‐caprolactone polymerisation, affords trans‐polyisoprene or (trans‐polyisoprene/hex‐1‐ene copolymer)–poly(ε‐caprolactone) diblocks of various lengths. The single component initiator is an allylsamarocene compound. An atomic force microscopy study shows that these copolymers are efficient compatibilisers for poly(ε‐caprolactone) and polyisoprene blends.