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1.
Shu-Hua Cheng  Tzy-Hsiang Su 《Polymer》2005,46(16):5939-5948
Three new aromatic poly(amine-amide-imide)s (PAAIs) having pendent triphenylamine units were prepared from the phosphorylation polyamidation reactions of a newly synthesized diamine, N,N-bis(4-aminophenyl)-N′,N′-diphenyl-1,4-phenylenediamine, with three imide ring-preformed dicarboxylic acids. These PAAIs had inherent viscosities of 0.54-0.86 dL/g, and they were amorphous and readily soluble in many organic solvents and could be solution cast into transparent, tough, and flexible films with good mechanical properties. They displayed relatively high glass-transition temperatures (279-287 °C) and good thermal stability, with 10% weight-loss temperatures in excess of 522 °C in nitrogen and char yields at 800 °C in nitrogen higher than 67%. The solutions of polymers in NMP exhibited strong UV-vis absorption bands with a maximum around 315 nm. The hole-transporting and electrochromic properties were examined by electrochemical and spectroelectrochemical methods. Cyclic voltammograms of the PAAIs prepared by casting polymer solution onto an indium-tin oxide (ITO)-coated glass substrate exhibited two reversible oxidation redox couples at 0.67 and 1.08 V vs. Ag/AgCl in acetonitrile solution. All the PAAIs revealed very stable electrochromic characteristics, changing color from original pale brownish to green, and then to blue at 0.67 and 1.08 V, respectively.  相似文献   

2.
Two diamine monomers, 4,4′-[sulfonylbis(1,4-phenyleneoxy)]dianiline (III a ) and 4,4′-[sulfonylbis(2,6-dimethyl-l,4-phenyleneoxy)]dianiline (III b ), were prepared by an aromatic nucleophilic substitution of 4,4′-sulfonyldiphenol (I a ) and 4,4′-sulfonylbis(2,6-dimethylphenol) (I b ) with p-chloronitrobenzene in the presence of potassium carbonate, followed by hydrazine catalytic reduction of the intermediate dinitro compounds. The diamines III a and III b were used as monomers with various aromatic tetracarboxylic dianhydrides (IV a–f ) to synthesize polyimides. The polymerization was conducted in two steps via the formation of a poly(amic acid) precursor followed by thermal cyclodehydration. The poly(amic acid)s had inherent viscosities above 0.87 and up to 2.56 dL/g. Most poly(amic acid)s could be coated and thermodehydrated into flexible and transparent polyimide films. The polyimides derived from the dianhydrides containing-O-and-SO2-or-C(CF3)2-bridging groups between the phthalic anhydride units were soluble in some organic solvents such as N,N-dimethylacetamide (DMAc) and N,N-dimethylformamide (DMF). The glass transition temperatures (Tg) of the polyimides were in the range from 254 to 300 °C. The methyl-substituted polyimides exhibited slightly higher solubility and higher Tg compared to the corresponding unsubstituted polyimides. Thermogravimetric analysis (TG) showed that the polyimides containing methyl substitutents started to lose weight around 450 °C and the unsubstituted ones started to lose weight around 550 °C.  相似文献   

3.
Hui-Min Wang 《Polymer》2009,50(7):1692-4840
A new class of electrochemically active polyimides with di-tert-butyl-substituted N,N,N′,N′-tetraphenyl-1,4-phenylenediamine units was prepared from N,N-bis(4-aminophenyl)-N′,N′-bis(4-tert-butylphenyl)-1,4-phenylenediamine and various aromatic tetracarboxylic dianhydrides via a conventional two-step procedure that included a ring-opening polyaddition to give poly(amic acid)s, followed by chemical or thermal cyclodehydration. Most of the polyimides are readily soluble in many organic solvents and can be solution-cast into tough and amorphous films. They had useful levels of thermal stability, with relatively high glass-transition temperatures (276-334 °C), 10% weight-loss temperatures in excess of 500 °C, and char yields at 800 °C in nitrogen higher than 60%. Cyclic voltammograms of the polyimide films cast on the indium-tin oxide (ITO)-coated glass substrate exhibited two reversible oxidation redox couples at 0.70-0.74 V and 1.05-1.08 V vs. Ag/AgCl in acetonitrile solution. The polyimide films revealed excellent stability of electrochromic characteristics, with a color change from colorless or pale yellowish neutral form to green and blue oxidized forms at applied potentials ranging from 0.0 to 1.3 V. These anodically coloring polymeric materials exhibited high optical contrast of percentage transmittance change (Δ%T) up to 44% at 413 nm and 43% at 890 nm for the green coloration, and 98% at 681 nm for the blue coloration. After over 50 cyclic switches, the polymer films still exhibited good redox and electrochromic stability.  相似文献   

4.
Unsymmetrical and symmetrical diamine monomers containing trifluoromethyl groups, 2-trifluoromethyl-4,4′-diaminodiphenyl sulfide and 2,2′-bis(trifluoromethyl)-4,4′-diamino-diphenyl sulfide, were synthesized from 2-chloro-5-nitrobenzotrifluoride as a starting material in two steps, respectively. Diamine monomers were polymerized with PMDA, BPDA, BTDA, and ODPA using a solution imidization method with N-methyl-2-pyrrolidone as a solvent at 190 °C to obtain the corresponding polyimides. They had inherent viscosities that ranged from 0.54 to 0.71 dL/g in N-methyl-2-pyrrolidone at 30 °C. All of the synthesized polyimides showed good solubility in polar aprotic solvents and phenolic solvents regardless of the number of trifluoromethyl groups. The 5% weight loss temperatures of the polyimides are in the range of 534–561 °C in nitrogen, and 505–542 °C in air. The Tg values and the thermal expansion coefficients of these polymers are in the range of 234–325 °C and in the range of 47.4–63.2 ppm/°C, respectively. Also, all of the synthesized polyimides have relatively low refractive indices (around 1.6) and birefringence (below 0.36).  相似文献   

5.
Yun Jun Kim 《Polymer》2005,46(12):3992-4004
Soluble rod-like aromatic polyimides and polyamides containing curable pendent groups were synthesized. The polyimides (PIEANs) and polyamides (PAEANs) containing pendent enaminonitrile groups showed good thermal stability, and underwent curing reactions without the emission of volatile by-products above 300 °C to stable materials which were not soluble in any organic solvents. However, the polyimides (PIEONs) and polyamides (PAEONs) containing pendent enoxynitrile groups started to decompose around 300 °C, because of the instability of enoxynitrile groups. PAEONs underwent curing reactions around 420 °C in spite of the initial decomposition, but PIEONs exhibited only thermal degradation process. Thermal analyses of these polymers and the corresponding model compounds revealed that the curing of enaminonitrile groups proceeded via intermolecular crosslinking as well as intramolecular cyclization, while the enoxynitrile groups, known to undergo self-curing reaction, could not be cured by itself, and a reactive amine group was essential for the curing of the enoxynitrile groups.  相似文献   

6.
A novel conducting polymer was successfully synthesized via electropolymerization of N1,N4-bis(4-(1H-pyrrol-1-yl)phenyl)-N1,N4-diphenylbenzene-1,4-diamine (DPTPA). This polymer film exhibited six various colors under different potentials. Besides, this polymer film showed high optical contrast (41% at 852 nm, 52% at 617 nm) and fast switching time (1.3 s at 410 nm, 1.4 s at 852 nm and 0.6 s at 617 nm). Cyclic voltammogram and electro-optical study showed that the polymer film has a stable and well-defined reversible redox process as well as electrochromic behavior.  相似文献   

7.
Jinqing Qu  Toshio Masuda 《Polymer》2006,47(19):6551-6559
Novel acetylene monomers containing N-phenyl-substituted carbazole (Cz) and triphenylamine (TPA) groups, namely, 3-ethynyl-9-phenylcarbazole (1) and p-(N,N-diphenylamino)phenylacetylene (2) were synthesized, and polymerized with several Rh-, W-, and Mo-based catalysts. Poly(1) and poly(2) with high number-average molecular weights (15?500-974?000) were obtained in good yields (77-97%), when [(nbd)RhCl]2-Et3N (nbd = norbornadiene) was used as a catalyst. The polymers exhibited UV-vis absorption peaks derived from the Cz and TPA moieties at 250-350 nm and polyacetylene backbone above 350 nm. The UV-vis absorption band edge wavelengths of the polymers were longer than those of the corresponding monomers. Poly(2) exhibited a UV-vis absorption peak at a longer wavelength than poly(1) did, which indicates that poly(2) has main chain conjugation longer than that of poly(1). The molecular weights and photoluminescence quantum yields of the polymers obtained by the polymerization using [(nbd)RhCl]2-Et3N were larger than those of the Rh+(nbd)[η6-C6H5B(C6H5)3]-based counterparts. The cyclic voltammograms of the polymers indicated that they had clear electrochemical properties; the onset oxidation voltage of poly(1) was higher than those of N-alkyl-substituted Cz derivatives. The polymers showed electrochromism and changed the color from pale yellow to blue by application of voltage, presumably caused by the formation of charged polaron at the Cz and TPA moieties. The temperatures for 5% weight loss of the polymers were around 350-420 °C under air, indicating the high thermal stability.  相似文献   

8.
A new triphenylamine-containing AB2 type monomer with one carboxylic acid and two amino groups, 4-(bis(4-aminophenyl)amino)benzoic acid (3), was synthesized and used for the preparation of hyperbranched poly(triphenylamine amide)s. The self-polycondensation of the AB2 monomer (3) afforded hyperbranched poly(triphenylamine amide) with amino end groups. The molecular weight of the hyperbranched poly(triphenylamine amide) was 21,000 Da determined by light scattering. End-capped hyperbranched polyamides were isolated by the chemical modification of unreacted amino groups with various acid chlorides. All the hyperbranched poly(triphenylamine amide)s exhibit excellent solubility in organic solvents such as NMP, DMF, DMSO, and DMAc at room temperature. The viscosities of hyperbranched poly(triphenylamine amide)s are as low as about 0.15 dL/g due to their dendritic structures. Poly(triphenylamine amide)s end-capped with rigid benzene ring have higher thermal stability than those with amino or aliphatic end groups. The photoluminescence of the hyperbranched polyamides is blue-yellow emissions around 430-510 nm. The energy gaps of the hyperbranched poly(triphenylamine amide)s with different end groups are about 2.93 eV and are independent on the end groups, but the HOMO and LUMO energy levels are dependent on the end groups.  相似文献   

9.
Novel DNA-lipid complexes carrying carbazole and triphenylamine moieties were prepared by substituting the sodium counter cation with cationic amphiphilic lipids, namely lipid(Cz) and lipid(TPA), in which the actual mole ratios of phosphate to lipid were 1:1.10 and 1:0.83, respectively. The DNA-lipid(Cz) and DNA-lipid(TPA) complexes were soluble in common organic solvents including CHCl3, CH2Cl2, methanol and ethanol, while insoluble in THF, toluene, and aqueous solutions. CD spectroscopy revealed that the DNA-lipid complexes took a predominantly double helical structure in CHCl3 and methanol and that the helical structure was fairly stable against heating. Solutions of DNA-lipid(Cz) and DNA-lipid(TPA) complexes emitted fluorescence in 5.7 and 76.4% quantum yields, which were higher than those of the corresponding lipid(Cz) and lipid(TPA) (4.4 and 55.3%). The cyclic voltammograms of the complexes indicated that the oxidation potentials of DNA-lipid(Cz) and DNA-lipid(TPA) were 0.95 and 0.85 V, respectively. The onset temperatures of weight loss of the DNA-lipid complexes were both 220 °C according to TGA in air.  相似文献   

10.
Novel aromatic polypyromellitimides bearing (n-alkyloxy)biphenyloxy side chains were prepared by two-step polycondensation of 1,4-phenylenediamine (PDA) and biphenyl-4,4′-diamine (BZ) with 3,6-bis[4′-(n-alkyloxy)biphenyl-4-oxy]pyromellitic dianhydrides (CmB-PMDAs, m = 6, 8, 10, 12), which had been synthesized by the nucleophilic substitution of N,N′-diphenyl-3,6-dibromopyromellitimides with sodium 4-(n-alkyloxy)biphenoxides. Inherent viscosities of the poly(amic acid)s were in the 0.26-0.62 dL/g range. Poly{1,4-phenylene-3,6-bis[4′-(n-alkyloxy)biphenyl-4-oxy]pyromellitimide}s (CmB-PPIs) and poly{4,4′-biphenyl-3,6-bis[4′-(n-alkyloxy)biphenyl-4-oxy]pyromellitimide}s (CmB-BPIs) obtained in films by thermal imidization of the corresponding poly(amic acid)s were characterized by FT-IR spectroscopy and elemental analysis, and their crystalline structure and thermal properties were measured and discussed with respect to the side chain length. After the polyimide films were surface-treated by rubbing with velvet fibers, standard liquid crystal (LC) cells containing 4-cyano-4′-n-pentylbiphenyl (5CB) were fabricated and their LC-aligning properties were investigated in terms of pretilt angle. The pretilt angles were remarkably affected by side chain length and on surface of the polyimides with m = 6 and 8 LCs aligned parallel to the rubbing direction while on surface of the polyimides with m = 10 and 12 they aligned nearly or completely vertical to the rubbing direction.  相似文献   

11.
Eva M. Maya 《Polymer》2005,46(25):11247-11254
Three new aromatic polyimides containing one or two replaceable halogen atoms in the repeat unit have been prepared by one-pot polycondensation at high temperature from dianhydrides and diamines containing halogen atoms. The halogenated polyimides exhibited good thermal properties and great solubility in a wide range of organic solvents, which make them good candidates to prepare functional polymers. They also showed film-forming capabilities, good mechanical properties, and a very low ability to take water, with values of only around 1% water uptake. To show the usefulness of these polyimides as functional polymers, the halogen group of two of them was successfully replaced by 4-tert-butyl phenyl or 4-tert-butyl phenyl ethynyl groups by a Suzuki or a Sonogashira reaction, respectively.  相似文献   

12.
A novel triptycene-based dianhydride, 1,4-bis[4-(3,4-dicarboxylphenoxy)]triptycene dianhydride, was prepared from 4-nitro-N-methylphthalimide and potassium phenolate of 1,4-dihydroxytriptycene (1). The aromatic nucleophilic substitution reaction between 4-nitro-N-methylphthalimide and 1 afforded triptycene-based bis(N-methylphthalimide) (2), which hydrolyzed and subsequently dehydrated to give the corresponding dianhydride (3). A series of new polyimides containing triptycene moieties were prepared from the dianhydride monomer (3) and various diamines in m-cresol via conventional one-step polycondensation method. Most of the resulting polyimides were soluble in common organic solvents, such as chloroform, THF, DMAc and DMSO. The polyimides exhibited excellent thermal and thermo-oxidative stabilities with the onset decomposition temperature and 10% weight loss temperature ranging from 448 to 486 °C and 526 to 565 °C in nitrogen atmosphere, respectively. The glass transition temperatures of the polyimides were in the range of 221-296 °C. The polyimide films were found to be transparent, flexible, and tough. The films had tensile strengths, elongations at break, and tensile moduli in the ranges 95-118 MPa, 5.3-16.2%, and 1.03-1.38 GPa, respectively. Wide-angle X-ray diffraction measurements revealed that these polyimides were amorphous.  相似文献   

13.
14.
A series of novel organosoluble polyimides and copolyimides with a propeller-shaped triarylamine unit were prepared from diamine and various aromatic dianhydrides via direct polycondensation. All of the polymers possessed tough, flexible, and strong films with high molecular weights. The polyimide and copolyimide films revealed electrochromic characteristics, with a color change from pale yellowish at its neutral state, to green, and finally to blue at its oxidized state, at applied potentials ranging from 0 to 1.50 V. The polyimide (Ib) film exhibited switching times of 4.5 s at 1.08 V at 424 and 877 nm and 1.9 s for fast bleaching due to a pendent substituted 2-phenyl-2-isopropyl group. Cyclic voltammetry (CV) of the polymer films showed two reversible redox couples at potentials of 0.91-0.99 V and 1.30-1.38 V, respectively. The CV results of the model compound M1 and model polyimide M2, were not a match to the oxidation peaks of polyimide Ib, indicating that the contribution of the oxidation was not only from the electron removal of nitrogen atoms.  相似文献   

15.
Two bisphenols, viz., 4,4′‐[1‐(2‐naphthalenyl)ethylidene]bisphenol and 4,4′‐[1‐(2‐naphthalenyl) ethylidene]bis‐3‐methylphenol were prepared by condensation of commercially available 2‐acetonaphthanone with phenol and o‐cresol, respectively. A series of new aromatic polyesters containing pendent naphthyl units was synthesized by phase‐transfer‐catalyzed interfacial polycondensation of these bisphenols with isophthaloyl chloride, terephthaloyl chloride, and a mixture of isophthaloyl chloride/terephthaloyl chloride (50 : 50 mol %). Inherent viscosities of polyesters were in the range 0.83–1.76 dL g−1, while number average molecular weights (Mn) were in the range 61,000–235,000 g mol−1. Polyesters were readily soluble in organic solvents such as dichloromethane, chloroform, tetrahydrofuran, m‐cresol, pyridine, N,N‐dimethylformamide, N,N‐dimethylacetamide, and 1‐methyl‐2‐pyrrolidinone at room temperature. Tough, transparent, and flexible films were cast from a solution of polyesters in chloroform. X‐Ray diffraction measurements displayed a broad halo at 2θ ≅ 19° indicating the amorphous nature of polyesters. Glass transition temperatures of polyesters were in the range 209–259°C. The temperature at 10% weight loss (T10), determined by TGA in nitrogen atmosphere, of polyesters was in the range 435–500°C indicating their good thermal stability. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010  相似文献   

16.
以邻甲酚酞与2-氯-5-硝基三氟甲苯为起始原料,通过两步有机反应——芳香亲核取代和氧化还原反应得到芳香二胺单体——4,4"-(2,2’三氟甲基)-二氨基苯氧基-3,3"-二甲基酚酞。利用共聚改性的思路,由两种二胺单体〔4,4"-(2,2"三氟甲基)-二氨基苯氧基-3,3"-二甲基酚酞和2,6-二氨基甲苯〕与一种二酐单体3,3",4,4"-二苯醚四甲酸二酐(ODPA)通过不同投料比以一步法高温缩聚制备得到同时含酚酞、三氟甲基和烷基结构系列共聚型聚酰亚胺。该系列共聚型聚酰亚胺具有优异的溶解性,在室温下不仅可溶于常见的高沸点溶剂:N-甲基吡咯烷酮(NMP),N,N-二甲基乙酰胺(DMAc)、N,N-二甲基甲酰胺(DMF)和二甲基亚砜(DMSO),在低沸点溶剂氯仿(CHCl3)、二氯甲烷(CH2Cl2)和四氢呋喃(THF)中也表现出优异的溶解性,可便利地通过其溶液浇筑制备得到系列高性能聚酰亚胺膜材料。该类膜材料玻璃化转变温度在275~314 ℃,其在N2和O2氛围中热失重10%时的温度分别为477~507 ℃和477~49 0 ℃。该类膜材料具有低的介电常数和良好的力学性能:其在1 MHz下介电常数在2.69~2.92之间,拉伸强度、弹性模量和断裂伸长率分别在80~92 MPa、1.2~1.8 GPa和9.2 %~13.5%之间。  相似文献   

17.
Man He  Jia Dai  Yiping Cui 《Polymer》2009,50(16):3924-2572
The novel fluorinated polyimides with side-chain nonlinear optical (NLO) chromophores were synthesized from hydroxyl polyimides, followed by the Mitsunobu reaction with NLO chromophores. Molecular structural characterization for the resulting polymers was achieved by 1H NMR, FT-IR, UV-Vis spectra, elemental analysis and gel permeation chromatography (GPC). The polymers exhibit excellent solubility in common organic solvents, good film-forming properties, high glass transition temperature (Tg) in the range from 193 to 200 °C and thermal stability up to 290 °C. The polyimides P1 and P2 containing hetarylazo chromophores with large hyperpolarizability possess a high electro-optic (EO) coefficient (r33), which is larger than that of the polyimide P3 attached DR1. Excellent temporal stability and low optical losses in the range of 1.9-2.1 dB/cm at 1.55 μm were observed for these polymers. Such new NLO fluorinated polyimides are distinguished by an excellent combination of NLO activity, temporal stability, and optical loss.  相似文献   

18.
A new fluorinated diamine monomer, [1,4-bis(4-amino-3-trifluoromethylphenoxy)benzene (2)], and a known isomeric analog 1,4-bis(4-amino-2-trifluoromethylphenoxy)benzene (3) were synthesized. A series of organosoluble polyimides Ia–d and IIa were prepared from the diamines (2, 3) and dianhydrides (a–d) by a high-temperature one-step method. The effects of the trifluoromethyl substituents on the properties of polyimides were evaluated through the study of their soluble, thermal, optical, and gas permeability properties. Polyimides (Ia–d) had glass transition temperatures between 229 and 279 °C, and the temperatures at 5% weight loss ranged from 510 to 533 °C under nitrogen. These polyimides could be cast into flexible and tough membranes from DMAc solutions. The membranes had tensile strengths in the range of 137–169 MPa, tensile modulus in the range of 1.6–2.2 GPa and elongations at break from 11% to 14%. The polyimide Ia with trifluoromethyl groups ortho to the imide nitrogen exhibited enhanced gas permeability, solubility, transparency, and thermal stability compared with the isomeric polyimide IIa with the CF3 group meta to the imide nitrogen. Thus, the effect of substituents in the ortho-positions of nitrogen on properties was greater than the effect of substituents in the meta-positions.  相似文献   

19.
A novel pyridine-containing aromatic dianhydride monomer, 2,6-bis[4-(3,4-dicarboxyphenoxy)benzoyl]pyridine dianhydride, was synthesized from the nitro displacement of 4-nitrophthalonitrile by the phenoxide ion of 2,6-bis(4-hydroxybenzoyl)pyridine, followed by acidic hydrolysis of the intermediate tetranitrile and cyclodehydration of the resulting tetraacid. A series of new polyimides holding pyridine moieties in main chain were prepared from the resulting dianhydride monomer with various aromatic diamines via a conventional two-stage process, i.e. ring-opening polycondensation forming the poly(amic acid)s and further thermal or chemical imidization forming polyimides. The inherent viscosities of the resulting polyimides were in the range of 0.51-0.68 dL/g, and most of them were soluble in aprotic amide solvents and cresols, such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and m-cresol, etc. Meanwhile, some strong and flexible polyimide films were obtained, which have good thermal stability with the glass transition temperatures of 221-278 °C, the temperature at 5% weight loss of 512-540 °C, and the residue at 800 °C of 60.4-65.3% in nitrogen, as well as have outstanding mechanical properties with the tensile strengths of 72.8-104.4 MPa and elongations at breakage of 9.1-11.7%. The polyimides also were found to possess low dielectric constants.  相似文献   

20.
Two series of new blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 4,4′-dicarboxytriphenylamine and 4,4′-dicarboxy-4″-methyltriphenylamine with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. These polymers were amorphous and readily soluble in various common organic solvents including DMAc, THF, and chloroform, and could be cast from their chloroform solutions into transparent films due to their excellent solubility. These polyarylates exhibited moderately high T g values (186–264 °C) and thermal stability. In THF solution, these triphenylamine-containing polyarylates showed UV-Vis absorption bands at 359–365 nm and photoluminescence peaks around 427–451 nm in the blue region. Figure Two series of new blue photoluminescent aromatic polyesters (polyarylates) were synthesized from 4,4’-dicarboxytriphenylamine and 4,4’-dicarboxy-4”-methyltriphenylamine with various bisphenols by the diphenylchlorophosphate (DPCP) activated direct polycondensation in a medium of pyridine and lithium chloride. These polymers were amorphous and readily soluble in various common organic solvents including DMAc, THF, and chloroform, and could be cast from their chloroform solutions into transparent films due to their excellent solubility. These polyarylates exhibited moderately high Tg values (186-264 oC) and thermal stability. All the PL spectra of these polymers showed a blue shift when the solvent was changed from NMP to THF or chloroform. Solvation should increase the interaction between polymer chain and solvent, which may consume certain excitation energy and lead to increase on the emission wavelength.  相似文献   

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