Electrical and third-order nonlinear optical properties of poly(2-fluoro-1,4-phenylenevinylene) and its copolymers

Summary Poly(2-fluoro-1,4-phenylenevinylene), PFPV, and its copolymers have been synthesized via water soluble precursor route and their electrical and optical propreties were measured. It seems that electron-withdrawing fluorine substituent on phenylene ring increases the band-gap of PFPV and it affects electrical and optical properties. The conductivity values of FeCl₃-doped drawn polymer films ranged from 10^-1 to 10¹ Scm^-1 depending on their composition, and were 10 times larger than those of undrawn ones. The ⁽³⁾ value for undrawn PFPV, using THG technique at 1907nm fundamental wavelength, was 4.76x10^-12 esu.     

Synthesis,electrical and optical properties of multifunctional poly[2-(2-ethyl-hexyloxy)-1,4-phenylenevinylene]

Summary Branched monoalkoxy-substituted poly[2-(2-ethylhexyloxy)-1,4-phenylenevinylene] (EH-PPV) was prepared in thin films via the water-soluble precursor technique and solution elimination method. These precursor polymer films could be stretched up to 8 times, and the drawn films of the EH-PPV could be doped with I₂ and FeCl₃ to give conductivities of 5.28x10^-3 and 0.56 S/cm, respectively. The third-order nonlinear optical susceptibility of the polymer was determined by using third harmonic generation (THG) method at 1907 nm, fundamental wavelength. Measured ⁽³⁾(–3; ,,) value was 3.8x10^-12 esu. The maximum emission wavelength of EH-PPV film in photoluminescence spectrum was 560 nm, corresponding to the yellowish red color.     

Conformational structure and aggregation behavior of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] in toluene/nonane solutions

We identified the conformational structure, aggregation behavior and photophysical properties of poly[2-methoxy-5-(2-ethylhexyloxy)-1,4-phenylenevinylene] (MEH-PPV) in various toluene/nonane solutions dependent on nonane content. In dilute solution region (e.g., below the overlap concentration, c*), static light scattering (SLS) revealed that the stiffness of MEH-PPV decreased as nonane content was increased, attributed to a stronger interaction force between MEH-PPV backbones. However, MEH-PPV chains presented a more extended-wormlike conformational structure in toluene. Therefore, a looser intermolecular micellelike aggregates occurred easily between the ether side chains of MEH-PPV at the concentration exceeded the overlapping concentration in toluene and toluene/nonane solutions. Nevertheless, at higher nonane content, the micellelike aggregates were became highly compacted by the π–π complex force between MEH-PPV backbones, dominating the dynamic behaviors and photophysical properties of MEH-PPV in toluene/nonane solution. These results proved that two types of segmental association with distinct stability were identified for the MEH-PPV/toluene/nonane solutions upon prolonged aging. The highly stable, which could not be disrupted by heating, was attributed to the interaction force between ether side chains of MEH-PPV in both solutions. Other type was a weaker affinity force through π–π complex, which could be disrupted thermally, making the micellelike aggregates more compact to form the network structure in MEH-PPV-enriched at higher nonane content.     

Synthesis and characterization of the soluble luminescent poly[2-decyloxy-5-(4’-ethoxyphenyl)-1,4-phenylenevinylene]

Summary A new soluble luminescent poly[2-decyloxy-5-(4^′-ethoxyphenyl)-1,4-phenylene-vinylene] (DEP-PPV) is prepared by the dehydrohalogenation of 1,4-bis(bromo-methyl)-2-decyloxy-5-(4^′-ethoxyphenyl) benzene in this study. The structure and properties of the DEP-PPV are examined by ¹H NMR, FT-IR, UV/VIS, TGA, photoluminescence (PL), and electroluminescence (EL) analyses. The incorporation of a decyloxy substituent in the 2-position of phenylene ring makes the DEP-PPV soluble in organic solvents and eliminates tolan-bis-benzyl structure defects. The energy band gap of DEP-PPV in tetrahydrofuran is 2.36 eV. The PL peak of DEP-PPV solution shifts to higher wavelength as the solution concentration increases. The PL spectrum of the DEP-PPV film shows a peak at 546 nm and the one of the pristine PPV film does at 540 nm. This red shift of PL peak for the DEP-PPV as compared with that for the PPV indicates that the incorporation of a conjugated ethoxyphenyl group on the phenylene ring can increase the conjugation length of phenylenevinylene units in the DEP-PPV. With the DEP-PPV acting as a light-emitting polymer, a device is fabricated with a sequential lamination of ITO/PEDOT/DEP-PPV/Ca/Ag. The EL spectrum of the device shows a maximum emission at 530 nm, which corresponds to the yellowish-green light. The turn-on voltage of the device is about 16 V. Its maximum brightness is 46 cd/m² at a voltage of 18 V.     

Synthesis,crystal structure and nonlinear optical property of CsV2O5

The new nonlinear optical crystal CsV₂O₅ has been synthesized by solid state reaction and characterized by single-crystal X-ray diffraction and thermogravimetric analysis. The crystal CsV₂O₅ crystallizes in the orthorhombic system with space Ima2 space group. It is a layered structure that is very flat and strongly parallel to c. The striking structural feature is that the V atom in single crystallographic site has two different valence states (V⁴⁺ and V⁵⁺). The [V₂O₅]_n layer consists of corner-linked tetrahedron. The six tetrahedrons lie very nearly in the same z-plane forming almost regular hexagons. The Kurtz powder SHG measurement, using 1064 nm radiation, showed that the second-harmonic generation efficiency of CsV₂O₅ is about six times that of KDP.     

Synthesis and electrical properties of poly[2-(2-(4-trifluoromethyl)phenyl)ethenyl-1,4-phenylenevinylene] and PPV copolymers

Summary Poly[2-(2-(4-(trifluoromethyl)phenyl)ethenyl)-5-methoxy-1,4-phenylenevinylene] (PFEMPV) and a series of PPV copolymers containing 1,4-phenylenevinylene (PV) units were synthesized through a water-soluble precursor route, and their electrical and third-order nonlinear optical properties were studied. The PFEMPV films could not be doped with I₂, but FeCl₃-doped films showed an electrical conductivity of 5.0x10^-4 S/cm. The conductivities of FeCl₃-doped copolymer films ranged from 2.0x10^-3 to 2.0 S/cm depending on their copolymer compositions. The third-order nonlinear optical susceptibility, ⁽³⁾(–;,,–), was also investigated by the degenerate four wave mixing technique at 602 nm. The ⁽³⁾ value of PFEMPV was 6.9x10^-11 esu. The photoluminescence spectrum of PFEMPV shows its emission maximum at 550 nm.     

聚(2-甲氧基-5-辛氧基)对苯乙炔的合成与工艺研究

以叔丁醇钾作催化剂,采用去卤缩合聚合法,合成了不对称取代的聚(2-甲氧基-5-辛氧基)对苯乙炔聚合物电致发光材料.对反应温度、反应时间、催化剂、溶剂等工艺条件的影响规律进行了详细的研究.结果表明:反应物的纯度、用量对目标产物的产率和性能有较大的影响;碱性是影响脱氯缩合反应的关键因素;而反应温度和时间对缩合反应影响则相对较小,在一定温度下反应一定时间后其转化率基本不变.     

芳香族偶氮化合物三阶非线性光学材料的合成研究

将含有不同取代基的芳胺在0~5℃下与亚硝酸钠和盐酸进行重氮化反应(摩尔比为芳胺∶亚硝酸钠=1∶1.2),制得相应的重氮盐,再分别与苯代三聚氰胺(BGA)(摩尔比为芳胺∶苯代三聚氰胺=1∶0.8)发生偶合反应,最终得到一系列新的含有不同取代基的芳香族偶氮化合物,反应收率为57%~65%。通过红外、紫外、元素分析、核磁对其结构进行了表征。     

New NLO-functionalized poly(1,4-phenylenevinylene) derivative containing dinitrobenzene moiety as electron acceptor

Summary New NLO-functionalized poly(1,4-phenylenevinylene) (PDNAPV) containing 2,4-dinitroanilino group, was synthesized through organic-soluble precursor pathway. The prepared polymer was characterized with NMR, FT-IR, UV-visible and other spectroscopic methods to identify its properties. The result from the thermal analyses and spectroscopic techniques showed that the precursor was converted into PDNAPV around at 200°C without any decomposition of 2,4-dinitroanilino group. The second-order NLO coefficient (χ⁽²⁾) of poled PDNAPV film was determined by second-harmonic generation technique. The resonant χ⁽²⁾ value was 26 pm/V and the resonance-corrected value (χ⁽²⁾(0)) was 12 pm/V, which was stable at room temperature for a month Received: 16 February 2001/Accepted: 13 March 2001     

Synthesis of a diacetylene-containing polyisophthalate and its third-order nonlinear optical susceptibility

In order to obtain amorphous thin films of a polydiacetylene, a polyisophthalate containing a push–pull diacetylene chromophore was synthesized by the reaction of p-(N,N-diethanolamino)-p’-nitrodiphenylbutadiyne with isophthaloyl chloride in anhydrous 1-methyl-2-pyrrolidone. The polymer was soluble in organic solvents, such as chloroform, tetrahydrofuran, dimethylformamide, etc., and films with good optical quality were obtained by spin coating from its N-methyl-2-pyrrolidone solution. It was characterized by ¹H-NMR, IR, DSC, UV–Visible, X-ray, etc. The diacetylene groups underwent polymerization in the film when irradiated with UV light at 120 °C under Ar atmosphere, and it contained free radicals with a radical concentration of 10¹⁶ radicals/g. The third-order nonlinear optical susceptibility, χ⁽³⁾, of the polymer film measured by the Z-scan technique at 1064 nm was not noticeable, but when the film was heated and irradiated with UV light, a χ⁽³⁾ value of 6.4?×?10^?10 esu was obtained due to increase in π-conjugation by the formation of polydiacetylene in the side chain.     

Synthesis and characterization of poly(1,5-naphthylene vinylene) and its copolymers with poly(2-methoxy-5-(2′-ethylhexyloxy)-p-phenylene vinylene)

Poly(1,5-naphthylene vinylene) (PNV) and its copolymers with poly(2-methoxy-5-(2′-ethylhexyloxy)-p-phenylenevinylene) (MEH-PPV) were synthesized via a liquid-solid two-phase reaction. The liquid phase was a tetrahydrofuran (THF) solution of the monomers, 1,4-bis(bromomethyl)-2-methoxy-5-(2-ethylhexyloxy)benzene (MOEHODCX) and 1,5-bis(bromomethyl) naphthalene (DBMN), and contained a certain amount of tetrabutylammonium bromide (TBAB) as a phase transfer catalyst. The solid phase was potassium hydroxide particles with diameters smaller than 2 mm. The structures of the polymers were studied by infrared and Raman spectroscopies. The solutions of the copolymers emitted green light. The UV-vis and photoluminescence spectral bands of the copolymers showed blue shifts with the increase in their PNV contents. A polymer light-emitting diode was fabricated with the copolymer prepared by copolymerization MOEHODCX and DBMN with feeding molar ratio of 1:1, and its luminescence efficiency was measured to be 0.069.     

Synthesis and property of end-functionalized poly(cis-1,4-butadiene) and its application to rubber compound

This article describes the successful quasi-living polymerization of 1,3-butadiene (BD) to high cis content butadiene rubber (HCBR) and the terminal functionalization of HCBR for application to rubber compound. A catalyst system based on neodymium carboxylate and organoaluminum compounds was prepared and employed to polymerize BD. Polymerization resulted in mostly proportional growth of molecular weight to the conversion while maintaining molecular weight distribution in relatively narrow range. The reactivity of chain end after the completion of polymerization was confirmed by comparing UV absorbance of polymers before and after the addition of chromophore compound to the unterminated polymerization mixture, as measured with size exclusion chromatography (SEC). A variety of functionalizing agents, which can provide end-groups of polymer with potential affinity to silica surface, was explored. Among them, compounds with epoxy, ketone, and ketimine groups produced polymers with clear evidences of functionalization. The HCBR functionalized with epoxy-containing alkoxysilane compound was tested in silica-filled rubber compound and showed remarkable improvement of silica dispersity as seen by change of viscoelastic responses. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47985.     

Synthesis and properties of poly (1,4-cyclohexanedicarboxylic anhydride)

Summary Polyanhydrides from cycloaliphatic 1,4-Cyclohexanedicarboxylic acid (1,4-CHDA) were synthesized by melt polycondensation and characterized by WAXD, FTIR and DSC. The results show that these polymer displayed strong crystallinity with highly melting point and can't be dissolved in common solvents. The polymers, which come from different original isomer conformation CHDA, show different melting point and DSC curve. The isomerization happened during the polymerization and reached an equilibrium point at last. By melt polycondensation, the high cis-isomer content polyanhydride is difficult to obtained. Received: 24 May 2000/Revised version: 4 September 2000/Accepted: 6 September 2000     

2-硝基-5-甲氧基苯丙酮的合成

文章以2-硝基-5-氯苯甲酸为原料,经四步反应以54%的总收率制得了合成SN38所需的中间体2-硝基-5-甲氧基苯丙酮,其结构经过核磁、质谱等进行了结构表征。该方法具有原料易得、操作简单、步骤少、收率高等优点。     

Synthesis and characterization of poly(1,4-dihydroxyanthraquinone terephthalate)

A novel polymeric dye containing an anthraquinone ring was prepared by solution polycondensation. The molecule geometry was fully optimized on the basis of the AM1 method. The hydrogen bond was formed and retained coplanarity in the molecular structure. In its UV spectrum, a large hypsochromic shift and a hypochromic effect were observed due to polyesterification. The polymeric dye was also characterized by means of IR and TG. Its thermal degradation mechanism was elucidated. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 81: 2246–2248, 2001     

Synthesis,crystal structure and nonlinear optical property of cadmium(II) and copper(II) complexes with novel chiral ligand

Two novel metal-organic frameworks (MOFs) [Cd(3-MPCA)₂ · H₂O] · 5.5H₂O (1) and [Cu(3-MPCA)₂ · H₂O] · 4H₂O (2) [3-MPCA⁻ = (1R, 3S)-1,2,2-trimethyl-3-(pyridin-3-ylmethylcarbamoyl)cyclopentanecarboxylate] were hydrothermally synthesized and characterized by X-ray crystallography. Complexes 1 and 2 are homochiral and have similar one-dimensional (1D) chain structure, which are further linked by strong hydrogen bonds to give 3D architectures. There are oxygen hexmers and heptamers from water molecules and carbonyl group in 1 with O⋯O distances and O–O–O angles comparable to the corresponding values in ice. Nonlinear optical measurements on powdered sample of 1 and 2 revealed that they display second-harmonic-generation (SHG) response of 0.8 and 0.3 times of that for urea, respectively.     

聚甲基丙烯酸氨基乙酯的合成及染色性能

以白油为分散介质,偶氮二异丁腈为引发剂,甲基丙烯酸氨基乙酯为单体,采用反相悬浮聚合法合成聚甲基丙烯酸氨基乙酯(PTAM),研究了引发剂用量、反应温度、反应时间、单体浓度对PTAM特性粘数的影响。将PTAM与聚丙烯腈(PAN)共混纺丝制得共混纤维,用酸性染料染色,考察其上染率。结果表明:合成PTAM的最佳工艺条件为引发剂质量分数0.05%,单体质量分数60%,反应温度65℃,反应时间2h,所得PTAM的特性粘数为690mL/g。染色实验结果表明,PTAM质量分数为7%时,PAN共混纤维的上染率达88%。     

Synthesis and properties of poly(ethylene-1,4-cyclohexanedimethylene naphthalate)

Copolyesters were synthesized from bis(hydroxyethyl) naphthalate/bis(hydroxymethylcyclohexane)naphthalate (BHEN/BHCN) with various compositions. Copolyesters having intrinsic viscosities of 0.58–0.65 dL g were obtained by melt polycondensation in the presence of metallic catalysts. The optimum condition for polyethylene-1,4-cyclohexanedimethylene naphthalate (PECN) copolyester manufacturing is the transesterification under a nitrogen atmosphere for 4 h at a temperature of 245 ± 5°C followed by polymerization under 2 mmHg for 50 min at a temperature of 290–320°C. Most copolyesters have better thermal stability than has poly(ethylene naphthalate) (PEN) and the effect of the cyclohexane–dimethylene structure on the thermal and crystalline properties of the resulting copolyesters was investigated using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA). Glass transition temperatures of the copolyesters were in the range of 115.2–138.4°C, and 10% weight losses in nitrogen were all above 453°C. The solubility, crystallinity, and moisture absorption of the copolyesters were also investigated. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 67:2245–2252, 1998