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1.
Homopolymers of 2-, 3- and 4-trifluoromethylstyrene, 4-perfluoroisopropylstyrene, 3,5-bis-trifluoromethyl-styrene and a 1 : 1 copolymer of 2,4- and 2,5-bis-trifluoromethyl-styrene have been synthesized and the refractive indices nD, Abbe-numbers νD and glass transition temperatures of the polymers have been determined. With regard to optical applications poly-2-trifluoromethyl-styrene is particularly interesting since its optical properties are in a region of the n-ν-diagram that has not been reached by thermoplastic polymers or inorganic glasses before. The most important mechanical and thermal properties of this polymer are reported. Reactivity ratios of the binary copolymerisation of 2-trifluoromethyl-styrene with styrene, methyl-methacrylate and n-butyl-acrylate are listed as well as optical data and glass transition temperatures of some copolymers of 2-trifluoromethyl-styrene. 相似文献
2.
Summary
An efficient method for the synthesis of PPV based polymers, poly ( 2,5-dimethyl-1,4-phenylene vinylene) (DMe-PPV) and poly
(2,5-dimethoxy-1,4-phenylene vinylene) (DOMe-PPV) were developed using 2,5-dimethyl-1,4-bis ( chloromethyl ) benzene and 2,5-dimethoxy
1,4-bis ( chloromethyl ) benzene via vapor phase pyrolysis and followed by vapor deposition polymerization. The structure
of polymer films were confirmed by FT-IR, solid state NMR and elemental analysis. Thermal gravimetry analysis reveals that
the precursor polymer films form a conjugated polymer after thermal conversion at 250°C. The optical and electrical properties
of the polymer films were investigated by UV-Vis absorption and photoluminescence spectroscopies. Electroluminescent devices
were fabricated using these polymers.
Received: 18 May 2000/Revised version: 21 July 2000/Accepted: 28 July 2000 相似文献
3.
Relationship between degree of polymerization and optical and thermal properties of fluorene in polycarbonate polymers
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The influences of average degree of polymerization (Dp) and terminal group on thermal and optical properties of high refractive indexed transparent polymers were investigated. In this study, 9,9‐bis[4–(2‐hydroxyethoxy) phenyl] fluorene (BPEF) homo polymer was selected because it has been used as a representative monomer in high refractive index polymers as well as its unique property. BPEF has stable amorphous phase and reacts like a polymer. Its unique reaction allows continuous investigation from monomer to polymer. For hydroxyl‐terminated polymer, the refractive index (nd) decreased with increasing Dp. On the other hand, for a phenolic‐terminated group, nd increased with increasing Dp, and both converged to same value in high Dp region. As for glass transition temperatures (Tg), both terminal group series were increased as Dp increased. Though Tg of hydroxyl‐terminated polymer was higher than that of phenolic‐terminated polymer in the low Dp region, both converged to the same value and the inverse number of Tg had linear correlation against the weight percentage of carbonyl groups (CO), which was calculated by Dp. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 45042. 相似文献
4.
Summary
Arylene-vinylene-containing polymers with fully aromatic backbone structures were prepared by the palladium-catalyzed hydroarylation
polymerization of diethynylbenzene derivatives with diiodobenzene and alkylmalonate anions as a hydride source. For instance,
the polymerization of 1,4-bis(4'-dodecyloxy)phenylethynylenebenzene, diiodobenzene, and sodium diethyl benzylmalonate was
carried out at 80°C for 2 days in 1,4-dioxane in the presence of Pd(OAc)2 / tri-o-tolylphosphine (7 equiv. to Pd) to produce a polymer (M
n= 6,390, M
w/M
n= 1.53) in high yield (86 %). Using various diethynylbenzene derivatives, polymers having arylene-vinylene units were also
obtained in high yields.
Received: 16 December 1999/Accepted: 20 January 2000 相似文献
5.
Tissa Sajoto Shree Prakash Tiwari Huifang Li Chad Risko Stephen Barlow Qing Zhang Jian-Yang Cho Jean-Luc Brédas Bernard Kippelen Seth R. Marder 《Polymer》2012,53(5):1072-1078
A series of conjugated polymers has been synthesized by Sonogashira coupling of N,N′-bis(2-octyldodecyl)-2,6-dibromonaphthalene-1,4,5,8-bis(dicarboximide) and four para-diethynylbenzene derivatives: 1,4-diethynyl-2,5-dihexadecyloxybenzene, 1,4-diethynyl-2,5-bis(2-octyldodecyloxy) benzene, 1,4-bis(2-ethylhexyl)-2,5-diethynylbenzene, 1,4-diethynyl-2,5-bis(trifluoromethyl)benzene. The polymers display absorption maxima at wavelengths ranging from 530 nm to 654 nm with molar absorptivities ranging from ca. 4 to 7 × 104 M?1 cm?1. The peak reduction potentials, determined by differential pulse voltammetry, for polymer films varied from ?0.93 to ?1.14 V vs. ferrocenium/ferrocene with the trifluoromethyl-substituted derivative being the most readily reduced. All four polymers exhibited electron transport characteristics in bottom-gate/top-contact field-effect transistors, showing average electron mobility values ranging from 1.4 × 10?4 to 3.7 × 10?3 cm2 V?1 s?1. 相似文献
6.
《塑料、橡胶和复合材料》2013,42(7):295-299
AbstractTwo series of polyimides and copolyimdes were solution cast into transparent, flexible and tough films. The glass transition temperatures T g obtained from dynamic mechanical analysis were moderate compared with commercial polyimides such as Dupont Vespel®. The T gs for the majority of polymers derived from monomer 1 (2′,5′-bis(p-aminophenoxy)-[1,1′;4′,1≥]terphenyl) (1A-F) were higher than those of polymers derived from monomer 2 (2,5-bis(p-aminophenoxy)biphenyl) (2A-F). The thermal expansion coefficients of the two series of polymers were moderate and comparable. The maximum elongations and moduli of polymers 2A-F were larger than those of polymers 1A-F possibly because polymers 2A-F were more flexible than polymers 1A-F. The relative dielectric permittivities of both series of polymers were measured and exhibited a low value from 2 49 to 3 01 at 100 kHz. In contrast, the relative permittivities calculated using the Clausius-Mosotti relationship were higher. Incorporation of non-coplanar diamines into the polymer chain causes an increase in free volume, which may account for the decrease in relative permittivities. 相似文献
7.
Prashant S. Patil Nanda S. Haram Ravindra R. Pal N. Periasamy Prakash P. Wadgaonkar Manikrao M. Salunkhe 《应用聚合物科学杂志》2012,125(3):1882-1889
Novel photoluminescent donor–acceptor poly(p-phenylenevinylene)-type conjugated polymers containing thiophene and 1,3,4-thiadiazole units in the main chain were synthesized from 2,5-bis(5-bromomethyl-2-thienyl)-1,3,4-thiadiazole and 1,3/1,4-benzenedialdehyde by Wittig–Horner reaction. The synthesized polymers were characterized by the use of thermal analysis and spectroscopic (infrared, UV-visible absorption, and photoluminescence) measurement. The resultant material exhibited bluish green, green, and orange fluorescence in their solution and thin film and solid forms, respectively. The redox property of the polymers has also been studied by cyclic voltammetry. The optical and electrochemical studies reveal that these novel polymers are new promising materials for the development of efficient polymer light-emitting diodes. © 2012 Wiley Periodicals, Inc. J Appl Polym Sci, 2012 相似文献
8.
Srivatsan Srinivas Marvin Graham M. Heather Brink Slade Gardner Richey M. Davis James E. McGrath Garth L. Wilkes 《Polymer Engineering and Science》1996,36(14):1928-1940
Novel high performance semicrystalline polyimides, based on controlled molecular weight phthalic anhydride (PA) endcapped 1,4-bis(4-aminophenoxy)benzene (TPEQ diamine) and oxydiphthalic dianhydride (ODPA), were synthesized. They exhibited excellent thermal stability in nitrogen and air atmospheres as determined by thermogravimetric analysis (TGA). The glass transition temperatures (Tg) for these polymers ranged from 225°C for the 10,000 Mn (10K) polymer, to 238°C for the 30,000 (30K) Mn material. The observed melting temperatures for all the polymers were ∼420°C. The crystallization behavior of these polymers showed a strong molecular weight dependence, as illustrated by the observation that the 10K and 12.5K polymers crystallized with relative ease, whereas the 15K, 20K, and 30K polymers showed little or no ability to undergo thermal recrystallization. The thermal stability of these polymers above Tm was investigated by studying the effect of time and temperature in the melt on the cold crystallization and melting of these polymers. Increased time and temperature in the melt resulted in lower crystallinity because of melt state degradation, such as crosslinking and branching, as evidenced by an increase in melt viscosity, which was more prominent for the higher molecular weight polymers. 相似文献
9.
4-(Trifluorovinyloxy)benzaldehyde was treated under Wittig conditions with 4-dihexyloxy-2,5-xylenebis(triphenylphosphoniumbromide) to form 1,4-bis(2′-(4-trifluorovinyloxyphenyl)ethenyl)-2,5-dihexyloxybenzene, a novel phenylene vinylene-bistrifluorovinyl ether monomer. Cyclopolymerization afforded an insoluble, non-luminescent material likely due to cross-addition reactions between phenylene vinylene olefin and trifluorovinyl ether (TFVE). However, 1,2-bis(4-formylphenoxy)hexafluorocyclobutane was polymerized with 1,4-dihexyloxy-2,5-xylenebis(triphenylphosphoniumbromide) and 1-methoxy-4-(2-ethylhexyloxy)-2,5-xylenebis(triphenylphosphoniumbromide) under Wittig conditions to yield two novel poly(perfluorocyclobutyl-co-phenylene vinylene) polymers. The polymers are of moderate molecular weight (8600-8700 Mn), show excellent thermal stability (Td = 390-405 °C), and are readily soluble in common organic solvents. The materials are highly fluorescent in both solution and thin film with solution quantum yields of 68 and 71%. 相似文献
10.
M. A. Del Valle J. Moreno F. R. Díaz L. H. Tagle J. C. Bernde Y. Tregoüet 《应用聚合物科学杂志》2001,81(8):2019-2026
The synthesis of poly(2,5‐selenophen‐oxo‐1,4‐phenylen‐selenide‐1,4‐phenylene‐oxo) (I) and poly(2,5‐selenophen‐oxo‐1,4‐phenylen‐diselenide‐1,4‐phenylen‐oxo) (II) by reaction of 2,5‐bis(1,4‐bromo‐phenylen‐oxo‐)‐selenophene with sodium selenide or diselenide, respectively, using dimethylformamide as solvent, is described. Both monomers and polymers were characterized by elemental analysis, melting point, and FTIR spectroscopy. Polymers I and II were doped with iodine and SbF5 and characterized by SEM and XPS. Also, the conductivity and the Tg values were determined. For both polymers the best doping agent was iodine, although polymer II always presented higher conductivity, reaching values of about 6 · 10?9 S · cm?1. The Tg values suggest a likely crosslinking of the chains in polymer II when doped with SbF5. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2019–2026, 2001 相似文献
11.
Silvia Colella Giovanna Melcarne Marco Mazzeo Giuseppe Gigli Roberto Grisorio Gian Paolo Suranna 《Polymer》2011,52(13):2740-2746
New random poly(arylene-vinylene)s obtained by combining different amounts of benzo[2,1,3]thiadiazole units with 9,9-dialkylfluorene and/or 1,4-dialkoxybenzene building blocks were synthesized by the Suzuki-Heck polymerization and characterized for use in bulk hetero-junction solar cells. Their optical, electrochemical, morphological and photovoltaic features were investigated. Notwithstanding the relatively low weight-average molecular weights of the obtained polymers (7000-13000 Da), they formed good quality films by spin-coating. UV-Vis measurements permitted the evaluation of their band gap (1.77-2.12 eV), enabling them to harvest a broad portion of the solar spectrum from 350 nm to 650-700 nm. An electrochemical study revealed that the copolymers are endowed with HOMO/LUMO energy levels suitable for both an efficient electron transfer and a high open circuit voltage (Voc) for devices embodying the polymer/PCBM blends. This investigation pinpoints the important role of the copolymer composition (in terms of molar ratio of the monomeric units) on the performance of the donors in BHJs. In fact, in disagreement with the presumed Voc and current densities, the terpolymer poly[1,4-bis(2-ethylhexyloxy)-2,5-phenylene-vinylene-co-9,9-bis(2-ethylhexyl)-2,7-fluorenylene-vinylene-co-4,7-benzo[2,1,3]thiadiazolylene-vinylene] showed the best performance of the copolymer series, with a PCE of 0.4% and a Voc of 0.76 V, probably due to the favorable phase separation in the blend and consequently a better exciton dissociation. 相似文献
12.
Zongqiang Yu Songting Tan Yingping Zou Benhu Fan Zhuliang Yuan Yongfang Li 《应用聚合物科学杂志》2006,102(4):3955-3962
Two novel copolymers of polyfluorenes/poly(p‐phenylenevinylene)s copolymers with p‐tert‐butyl‐phenylenemethylene groups in the C‐9 position of alternating fluorene unit, poly[1,4‐(2,5‐dibutyloxyl)‐phenyleneviny lene‐alt‐9‐(p‐tert‐butyl‐phenylenemethylene)fluorene] and poly[1,4‐(2,5‐dioctyloxyl)‐phenylenevinylene‐alt‐9‐(p‐tert‐butyl‐phenylenemethylene)fluorine], have been synthesized via the Heck polycondensation reaction. The synthesized polymers were characterized by FTIR, NMR, DSC, TGA, UV–vis, and PL spectra. The polymers showed high glass transition temperatures and good thermal stability. A polymer light‐emitting diode with the configuration ITO/PEDOT:PSS/P2/Ca/Al has been fabricated. The device emitted a yellow light with a peak wavelength of 578 nm similar to the PL spectra of the copolymer film. A maximal luminance of 534 cd/m2 was obtained at a driving voltage of 24.5 V. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3955–3962, 2006 相似文献
13.
Two series of novel rod–coil block copolymers, poly(ɛ-caprolactone)-b-poly{2,5-bis[(4-methoxyphenyl) oxycarbonyl] styrene} (PCL-b-PMPCS) and poly{2,5-bis[(4-methoxyphenyl) oxycarbonyl] styrene}-b-poly(ɛ-caprolactone)-b-poly{2,5-bis[(4-methoxyphenyl) oxycarbonyl] styrene} (PMPCS-b-PCL-b-PMPCS), were successfully synthesized via atom transfer radical polymerization in chlorobenzene solution using macro-initiator and CuBr/Sparteine complex as catalyst. The results show that the number average molecular weight Mn increased versus the monomer conversion and that the polydispersity Mw/Mn was quite narrow (<1.35), which were the character of controlled polymerization. The structure of the block copolymers was experimentally confirmed by 1H NMR. And the liquid crystalline behavior of them was studied using DSC and POM. The data obtained implied that the block copolymers with low molar percentage of PMPCS block could show Tm of PCL. While only the copolymers with long rigid segment PMPCS could form liquid crystalline phase, which was quite stable with a high clearing point. 相似文献
14.
Souheng Wu 《Polymer Engineering and Science》1990,30(13):753-761
We present chain structure, phase morphology, and toughness relationships in thermoplastic polymers and polymer/rubber blends. In neat polymers, molecular aspects of craze/yield behavior are controlled by two chain parameters: entanglement density νe and characteristic ratio C∞. The crazing stress is proportional to ν, and the yield stress is proportional to C∞. The dispersed rubber toughens a polymer/rubber blend mainly by promoting energy dissipation of the matrix. The toughening efficiency correlates with the rubber phase morphology and the chain structure of the matrix. 相似文献
15.
The reaction of π-conjugated poly(p-phenylene)s (PPPs) consisting of 2- or 3-amino-1,4-phenylene (NH2Ph) and 2,5-dioctyloxy-1,4-phenylene (OctPh) or 9,9-dihexylfluorene-2,7-diyl (HexFlu) rings [polymer-1: (NH2Ph-OctPh)n and polymer-2: (NH2Ph-HexFlu)n] with 7,7,8,8-tetracyanoquinodimethane (TCNQ) yielded gel-1 and gel-2. These gels were form through a charge transfer (CT) between the NH2 group and TCNQ, causing the gels to be linked by a TCNQ dianion. ESR measurements suggest that radical species generated by CT in the gels are delocalized in the π-conjugated polymer backbone. UV–vis measurements revealed that CT between the NH2 group and TCNQ was essential for gel formation. When a dimethyl sulfoxide (DMSO)/TCNQ solution was added to a chloroform solution of the polymers, the absorption corresponding to CT bands increased with an increasing amount of TCNQ. Photoluminescence (PL) measurements suggested that TCNQ served as a quencher for fluorescent polymer-1 and polymer-2. Quenching behavior was investigated by Stern–Volmer analysis. 相似文献
16.
Summary A series of polymers containing 2,5-disubstituted phenylene vinylene units, and the polymer containing 1,4-naphthalene vinylene units, were prepared by polymerization of their bis(sulfonium salts) through a base elimination reaction in solution. Films of these polymers were cast from aqueous solution and chemically treated (doped) with AsF5 vapor. The electrically conductivities of the doped films varied greatly with changes in polymer structure, with the highest value obtained of 1.8 ohm–1 cm–1 for poly (2,5-dimethoxyphenylene vinylene). 相似文献
17.
Nuannuan Ma Feng Guo 《Journal of Inorganic and Organometallic Polymers and Materials》2013,23(5):1177-1182
Two new coordination polymers, {[Cd2(PDC)2(H2O)2(L1)]·2H2O}n (1) and {[Cd (2,5-PDC)(H2O)(L2)]·H2O}n (2), have been obtained from hydrothermal reactions of Cd2+ ion with the 2,5-pyridinedicarboxylic acid (H2PDC) and two imidazole-containing ligands [L1 = 1,4-bis(imidazol-1-yl)benzene and L2 = 1,4-bis(1-imidazol-yl)-2,5-dimethylbenzene]. Complex 1 features a three-dimensional 6-connected rob topological net. Complex 2 shows a two-dimensional 6-connected hxl topological net. The structural differences between 1 and 2 demonstrate that the different imidazole-containing ligands play critical roles in the formation of the resulting frameworks. The photoluminescent properties of 1 and 2 have also been investigated. 相似文献
18.
Abdukaiyum Abdurashid Bahtiyar Ahat Abduheber Mirzehmet Tunsagul Awut Ismayil Nurulla 《Journal of Polymer Research》2016,23(5):92
A new type of π-conjugated polymers containing 2-diisopropylamino-1,3,5-triazine were prepared via Sonogashira or Suzuki coupling reaction. The structures of the polymers were performed by FT-IR, 1H-NMR, UV–vis spectroscopy, photoluminescence spectroscopy, gel permeation chromatography, thermal analysis and X-ray diffraction analysis. These derived polymers were soluble in common organic solvents such as tetrahydrofuran, chloroform, toluene, and showed good thermal stability. Polymers containing 1,4-diethynyl-2,5-bis(dialkoxy)benzene unit in polymer main chain emitted blue-green light in solution phase under UV light irradiation except with polymer containing 9,9-dioctylfluorene(blue light). Acidochromic behaviors of polymers were studied in CHCl3-CF3COOH mixtures. 9,9-Dioctylfluorene-containing polymer displayed better acidochromic property and linear relationship between absorbance and concentration with the concentration of CF3COOH from 5.384?×?10?4 to 26.92?×?10?4 mol/L. Electrochemical behaviors of polymers depicted p-doping and some hole-transporting properties. XRD results showed that polymers exhibited certain crystallinity. 相似文献
19.
Phase diagrams of two types of rigid rod polymer/flexible coil polymer/methanesulfonic acid (MSA) ternary systems were determined by polarized optical microscopy at ambient conditions. The rigid rod polymer is a wholly aromatic high temperature resistant (no measurable Tg) poly (p-phenylenebenzobisthiazole) (PPBT). One of the flexible coil polymers is a wholly aromatic high temperature resistant poly (2,5′(6′) benzimidazole) (ABPBI), the other is a thermoplastic poly[2,2′ -(1–4-phenylene)-6,6′ -bis (3-phenyl-quinoxaline)] (PPQ) with Tg of 359°C. The solvent is methane-sulfonic acid (MSA). The experimentally determined critical concentration points, Ccr, are in excellent agreement with Flory's recent theory. Total phase segregation between the polymer pair in ternary solution was predicted and observed at C > Ccr. Different decomposition mechanisms of phase separation were observed as a function of concentration. 相似文献
20.
A series of poly(propylene-co-1,4-cyclohexanedimethylene 2,5-furandicarboxylate)s (PPCFs) with different compositions were synthesized from bio-based aromatic monomer 2,5-furandicarboxylic acid and 1,3-propanediol (PDO), along with 1,4-cyclohexanedimethylene (CHDM). The chemical structure, composition, and sequence distribution of PPCFs were determined by nuclear magnetic resonance (1H NMR and 13C NMR). Results showed that the compositions of copolyesters depended on the feed molar ratio of PDO and CHDM, and all the obtained PPCFs copolyesters had triad component in a random sequential structure. With the addition of CHDM, the gas barrier properties of poly(propylene 2,5-furandicarboxylate) (PPF) deteriorated. However, when the content of CHDM reached 79%, PPCF79 still showed the CO2 and O2 barrier improvement factor of 4.5 and 3.25, respectively, which were better than those of poly(ethylene naphthalate), a well-known polymer with barrier property. Besides, PPCF79 showed good performance on tensile modulus, tensile strength, elongation at break, and the crystallization enthalpy was improved from 3.2 J g−1 for PPF to 30.7 J g−1 for PPCF79. It has the potential to serve as a promising bio-based polymer with excellent comprehensive performance. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47291. 相似文献