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Rod-coil Block Copolymers (rod-coil + block_copolymer)
Selected AbstractsSynthesis and Characterization of Novel Mesogen-Jacketed Liquid Crystalline Miktoarm Star Rod-Coil Block CopolymerMACROMOLECULAR RAPID COMMUNICATIONS, Issue 1 2006Jianfang Chen Abstract Summary: A series of novel mesogen-jacketed liquid crystal miktoarm star rod-coil block copolymers were synthesized via atom transfer radical polymerization (ATRP). Their architectures {coil conformation of styrene segment and rigid rod conformation of {2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (MPCS) segment} were confirmed by GPC, 1H NMR, and MALDI-TOF studies. The liquid crystalline behaviors of the synthesized copolymers are evidenced from POM observation. The liquid crystalline phase depends on the molecular weights of the rigid rod arm of miktoarm star copolymers. Miktoarm star rod-coil block copolymer. [source] A New Supramolecular Route for Using Rod-Coil Block Copolymers in Photovoltaic ApplicationsADVANCED MATERIALS, Issue 6 2010Nicolas Sary A new polymer blend formed by poly(3-hexylthiophene)-poly(4-vinylpyridine) (P3HT- P4VP) block copolymers and [6,6]-phenyl-C61-butyric acid methyl ester (PCBM) is reported. The P4VP and PCBM are mixed together by weak supramolecular interactions, and the resulting materials exhibit microphase separated morphologies of electron-donor and electron-acceptor rich domains. The properties of the blend, used in photovoltaic devices as active layers, are also discussed. [source] Synthesis and Characterization of Novel Mesogen-Jacketed Liquid Crystalline Miktoarm Star Rod-Coil Block CopolymerMACROMOLECULAR RAPID COMMUNICATIONS, Issue 1 2006Jianfang Chen Abstract Summary: A series of novel mesogen-jacketed liquid crystal miktoarm star rod-coil block copolymers were synthesized via atom transfer radical polymerization (ATRP). Their architectures {coil conformation of styrene segment and rigid rod conformation of {2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (MPCS) segment} were confirmed by GPC, 1H NMR, and MALDI-TOF studies. The liquid crystalline behaviors of the synthesized copolymers are evidenced from POM observation. The liquid crystalline phase depends on the molecular weights of the rigid rod arm of miktoarm star copolymers. Miktoarm star rod-coil block copolymer. [source] Synthesis, Morphology, and Properties of Poly(3-hexylthiophene)- block -Poly(vinylphenyl oxadiazole) Donor,Acceptor Rod,Coil Block Copolymers and Their Memory Device ApplicationsADVANCED FUNCTIONAL MATERIALS, Issue 18 2010Yi-Kai Fang Abstract Novel donor,acceptor rod,coil diblock copolymers of regioregular poly(3-hexylthiophene) (P3HT)- block -poly(2-phenyl-5-(4-vinylphenyl)-1,3,4-oxadiaz-ole) (POXD) are successfully synthesized by the combination of a modified Grignard metathesis reaction (GRIM) and atom transfer radical polymerization (ATRP). The effects of the block ratios of the P3HT donor and POXD pendant acceptor blocks on the morphology, field effect transistor mobility, and memory device characteristics are explored. The TEM, SAXS, WAXS, and AFM results suggest that the coil block fraction significantly affects the chain packing of the P3HT block and depresses its crystallinity. The optical absorption spectra indicate that the intramolecular charge transfer between the main chain P3HT donor and the side chain POXD acceptor is relatively weak and the level of order of P3HT chains is reduced by the incorporation of the POXD acceptor. The field effect transistor (FET) hole mobility of the system exhibits a similar trend on the optical properties, which are also decreased with the reduced ordered P3HT crystallinity. The low-lying highest occupied molecular orbital (HOMO) energy level (,6.08 eV) of POXD is employed as charge trap for the electrical switching memory devices. P3HT- b -POXD exhibits a non-volatile bistable memory or insulator behavior depending on the P3HT/POXD block ratio and the resulting morphology. The ITO/P3HT44 - b - POXD18/Al memory device shows a non-volatile switching characteristic with negative differential resistance (NDR) effect due to the charge trapped POXD block. These experimental results provide the new strategies for the design of donor-acceptor rod-coil block copolymers for controlling morphology and physical properties as well as advanced memory device applications. [source] Synthesis of well-defined rod-coil block copolymers containing trifluoromethylated poly(phenylene oxide)s by chain-growth condensation polymerization and atom transfer radical polymerizationJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 5 2010Yun Jun Kim Abstract Well-defined trifluoromethylated poly(phenylene oxide)s were synthesized via nucleophilic aromatic substitution (SNAr) reaction by a chain-growth polymerization manner. Polymerization of potassium 4-fluoro-3-(trifluoromethyl)phenolate in the presence of an appropriate initiator yielded polymers with molecular weights of ,4000 and polydispersity indices of <1.2, which were characterized by 1H nuclear magnetic resonance spectroscopy and gel permeation chromatography. Initiating sites for atom transfer radical polymerization (ATRP) were introduced at the either side of chain ends of the poly(phenylene oxide), and used for ATRP of styrene and methyl methacrylate, yielding well-defined rod-coil block copolymers. Differential scanning calorimetry study indicated that the well-defined trifluoromethylated poly(phenylene oxide)s showed high crystallinity and were immiscible with polystyrene. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 1049,1057, 2010 [source] Novel synthesis of rod-coil block copolymers by combination of coordination polymerization and ATRPJOURNAL OF POLYMER SCIENCE (IN TWO SECTIONS), Issue 17 2007Koji Ishizu Abstract Combination of coordination polymerization and atom transfer radical polymerization (ATRP) was applied to a novel synthesis of rod-coil block copolymers. The procedure included the following steps: (1) monoesterification reaction of ethylene glycol with 2-bromoisobutyryl bromide yielded a ,-bromo, ,-hydroxy bifunctional initiator, (2) CpTiCl3 (bifunctional initiator) catalyst was prepared from a mixture of trichlorocyclopentadienyl titanium (CpTiCl3) and bifunctional initiator. Coordination polymerization of n- butyl isocyanate initiated by such catalyst provided a well-defined macroinitiator, poly(n- butyl isocyanate)-Br (PBIC-Br), and (3) ATRP method of vinyl monomers using PBIC-Br provided rod (PBIC)-coil block copolymers. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 4037,4042, 2007 [source] Synthesis and Characterization of Novel Mesogen-Jacketed Liquid Crystalline Miktoarm Star Rod-Coil Block CopolymerMACROMOLECULAR RAPID COMMUNICATIONS, Issue 1 2006Jianfang Chen Abstract Summary: A series of novel mesogen-jacketed liquid crystal miktoarm star rod-coil block copolymers were synthesized via atom transfer radical polymerization (ATRP). Their architectures {coil conformation of styrene segment and rigid rod conformation of {2,5-bis[(4-methoxyphenyl)oxycarbonyl]styrene} (MPCS) segment} were confirmed by GPC, 1H NMR, and MALDI-TOF studies. The liquid crystalline behaviors of the synthesized copolymers are evidenced from POM observation. The liquid crystalline phase depends on the molecular weights of the rigid rod arm of miktoarm star copolymers. Miktoarm star rod-coil block copolymer. [source] | ||||||||||||||||||||||