首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Copolymers were synthesized through the chemically oxidative polymerization of N‐ethylaniline (EA) and aniline (AN) in five acid aqueous media. The polymerization yield, intrinsic viscosity, molecular weight, solubility, solvatochromism, electrical conductivity, and mechanical properties of the copolymer films were systematically studied through changes in the comonomer ratio, polymerization temperature, oxidant, oxidant/monomer ratio, and acid medium. Open‐circuit‐potential and temperature measurements of the polymerization solutions showed that the polymerization rate depended on the EA content, and the polymerization was an exothermic reaction. The resultant copolymers were characterized in detail with IR, ultraviolet–visible, and 1H NMR spectroscopy, gel permeation chromatography, wide‐angle X‐ray diffractometry, and scanning electron microscopy. The reactivity ratios of the monomer pair were calculated from the 1H NMR spectra of the copolymers formed at a low conversion. The polymers exhibited good solubility and interesting solvatochromism in most of the solvents and variable conductivity with the EA/AN ratio and doping state. The conductivity of the HCl‐doped copolymers increased monotonically from 5.61 × 10?7 to 2.55 × 10?1 S/cm with decreasing EA content from 100 to 0 mol % and showed a percolation transition between EA concentrations of 20 and 30 mol %. The EA/AN copolymers also had excellent film formability and flexibility together with high mechanical and oxygen‐enriching properties. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 6109–6124, 2004  相似文献   

2.
A new series of electrically conductive pure copolymer nanoparticles was facilely synthesized by using oxidative polymerization of aniline (AN) and sodium diphenylamine-4-sulfonate (SDP) in acidic media in the absence of stabilizer. The variation of the structure of the copolymer particles was comprehensively studied by carefully choosing several important parameters, such as the comonomer ratio, oxidant/monomer ratio, polymerization time and temperature, monomer concentration, acidic medium, and oxidant species. Analytical techniques used include IR and UV-visible spectroscopy, X-ray diffraction, laser particle analysis, atomic force microscopy, and transmission electron microscopy. It was found that the particle size varied significantly with the above-mentioned polymerization parameters, only changes in the salt concentration in the aqueous testing solution had no noticeable effect. The polymerization conditions were optimized for the formation of copolymer nanoparticles with sought-after properties. The doped copolymer particles of AN/SDP (50:50) at an oxidant/monomer molar ratio of 0.5 exhibit a minimum length of 50 nm and a minimum diameter of 44 nm. The bulk electrical conductivity of the copolymer particles increases greatly from 5.90x10(-4) to 1.15x10(-2) S cm(-1) with increasing AN content. Compared with barely soluble polyaniline, the copolymers exhibit a remarkably enhanced solubility in most solvents, including NH4OH and even water, due to the presence of the hydrophilic sulfonic groups. Nanocomposite films of the nanoparticles and cellulose diacetate exhibit a percolation threshold of down to 0.1 wt %, at which the film retains 98% of the transparency, 94% of the strength, and 5x10(7) times the conductivity of a pure cellulose diacetate film.  相似文献   

3.
A series of copolymers were easily synthesized via the chemical oxidative polymerization of 2‐pyridylamine (2PA) and aniline (AN) in an acidic aqueous medium. The yield, intrinsic viscosity, and solubility of the copolymers were studied through changes in the 2PA/AN molar ratio, polymerization temperature, oxidant, oxidant/monomer molar ratio, and polymerization medium. The resulting 2PA/AN copolymers were characterized by 1H NMR, Fourier transform infrared, wide‐angle X‐ray diffraction, and thermogravimetric techniques. The results showed that the oxidative copolymerization from 2PA and AN was exothermic. The resultant copolymers were amorphous and exhibited enhanced solubility in comparison with polyaniline. The 2PA/AN copolymers showed the highest decomposition temperature (530 °C), the slowest maximum‐weight‐loss rate (1.2 %/min), the largest char yield (45 wt %), and the greatest degradation activation energy (65 kJ/mol) in nitrogen. The thermostability of the copolymers was generally higher in nitrogen than in air. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 4407–4418, 2000  相似文献   

4.
A new series of copolymers was synthesized through the oxidative polymerization of pyrrole (PY) and o‐phenetidine (PHT) with inorganic oxidants in acidic media. The polymerization parameters including the mixing method of the oxidant with the comonomer, the comonomer ratio, the time, the temperature, the oxidant, the organic medium, and the acid were systematically optimized for the synthesis of copolymers with high yields, intrinsic viscosities, and solubility. The resultant copolymers were characterized by elemental analysis, infrared, ultraviolet–visible, solution high‐resolution 1H NMR and solid‐state high‐resolution 13C NMR, circular dichroism spectroscopy, and cyclic voltammetry. The results showed that the PY observed content in the copolymers was much higher than the PY feed content. The regular variation of the polymerization yield, intrinsic viscosity, solubility, macromolecular structure, and electroactivity of the resulting polymers with the comonomer ratio, together with the complete solubility of a PY/PHT (10/90) polymer in highly polar solvents, indicated the formation of real random copolymers containing both PY and PHT units rather than a mixture of two homopolymers. However, the polymers containing more than 59 mol % PY were not homogeneous copolymers consisting of soluble and insoluble parts. A semiquantitative relationship between the polymerization yield or solubility of the copolymers and the polarity index of the organic solvents was examined. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2073–2092, 2004  相似文献   

5.
《先进技术聚合物》2018,29(2):825-834
In this study, poly(acrylonitrile‐co‐styrene/pyrrole) or poly(AN‐co‐ST/Py) copolymer was successfully synthesized using microwave preparation technique, and its comparison with the conventional heating method is investigated. Different polymerization factors affecting on the preparation conditions and conversion yield such as monomer concentration, comonomers ratio, initiator concentration, cosolvent ratio, cosolvent type, polymerization temperature, and polymerization time have a considerable effect on the conversion yield %, functional groups, and molecular weight. The copolymerization process was approved by Fourier transform infrared, thermogravimetric analysis, 1H NMR spectroscopy, and gel permeation chromatography. The formation of poly(AN‐co‐ST/Py) nanoparticles was confirmed by SEM, and their possible formation mechanisms were also proposed. The SEM images of poly(AN‐co‐ST/Py) prepared by the microwave method showed that the synthesized copolymer had spikes or rods with spherical structure of the produced copolymers than the poly(AN‐co‐ST/Py) nanoparticles prepared by the conventional heating method. Microwave method showed advantages for the produced copolymers compared to that prepared by conventional method, where it can offer a copolymer in short time, high yield, and more thermally stable copolymers, rather than conventional method.  相似文献   

6.
Diblock copolymer membranes having a fluorinated segment and a sulfonic acid segment were prepared by living radical polymerization, solution casting, and crosslinking, followed by heat treatment. Diblock copolymers of 2,3,4,5,6‐pentafluorostyrene (PFS)/4‐(1‐methylsilacyclobutyl)styrene (SBS) and neopentyl styrenesulfonate (SSPen) (poly(PFS‐co‐SBS)‐b‐polySSPen)s were synthesized by nitoroxy‐mediated living radical polymerization. Self‐standing crosslinked membranes were obtained by casting a THF solution of the block copolymer with Pt catalyst. Heat treatment of the membrane at 230 °C induced decomposition of the neopentyl sulfonate esters to provide block copolymer membranes having a fluorinated segment and a free sulfonic acid segment. It was confirmed that the block copolymer with a high sulfonic acid content exhibited high ion exchange capacity and high proton conductivity as well as high thermal stability. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 4479–4485, 2008  相似文献   

7.
A series of poly(o‐/m‐toluidine‐coo‐/m‐aminoacetophenone) copolymers combining the features of high conductivity and processibility are synthesized and characterized by a number of techniques including 1H NMR; thermogravimetry; IR, Raman, and UV–visible spectroscopy; scanning electron microscopy; and X‐ray diffraction. The copolymers are synthesized by the emulsion and inverse emulsion methods using conventional ammonium persulfate and a new oxidant, benzoyl peroxide, respectively. The influence of the polymerization conditions such as the monomer feed ratios, solvent, and the nonsolvent is investigated. The composition of the resulting copolymers is determined by 1H NMR analysis. The conductivity of the copolymers varies with the aminoacetophenone content in the feed and the polymerization conditions. It is interesting that the conductivity of the copolymers is higher than that of the corresponding homopolymers. The results are rationalized on the basis of the effect of the ? COCH3 substituent on the polymer structure. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 4300–4310, 2004  相似文献   

8.
A novel sulfonated diamine monomer, 2,2′‐bis(p‐aminophenoxy)‐1,1′‐binaphthyl‐6,6′‐disulfonic acid (BNDADS), was synthesized. A series of sulfonated polyimide copolymers containing 30–80 mol % BNDADS as a hydrophilic component were prepared. The copolymers showed excellent solubility and good film‐forming capability. Atomic force microscopy phase images clearly showed hydrophilic/hydrophobic microphase separation. The relationship between the proton conductivity and degree of sulfonation was examined. The sulfonated polyimide copolymer with 60 mol % BNDADS showed higher proton conductivity (0.0945–0.161 S/cm) at 20–80 °C in liquid water. The membranes exhibited methanol permeability from 9 × 10?8 to 5 × 10?7 cm2/s at 20 °C, which was much lower than that of Nafion (2 × 10?6cm2/s). The copolymers were thermally stable up to 300 °C. The sulfonated polyimide copolymers with 30–60 mol % BNDADS showed reasonable mechanical strength; for example, the maximum tensile strength at break of the sulfonated polyimide copolymer with 40 mol % BNDADS was 80.6 MPa under high moisture conditions. The optimum concentration of BNDADS was found to be 60 mol % from the viewpoint of proton conductivity, methanol permeability, and membrane stability. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 222–231, 2007  相似文献   

9.
The copper(0)‐catalyzed living radical polymerization of acrylonitrile (AN) was investigated using ethyl 2‐bromoisobutyrate as an initiator and 2,2′‐bipyridine as a ligand. The polymerization proceeded smoothly in dimethyl sulphoxide with higher than 90% conversion in 13 h at 25 °C. The polymerization kept the features of controlled radical polymerization. 1H NMR spectra proved that the resultant polymer was end‐capped by ethyl 2‐bromoisobutyrate species. Such polymerization technique was also successfully introduced to conduct the copolymerization of styrene (St) and AN to obtain well‐controlled copolymers of St and AN at 25 °C, in which the monomer conversion of St could reach to higher than 90%. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

10.
A thiophene‐functionalized methacrylate monomer (3‐methylthienyl methacrylate) was synthesized via the esterification of 3‐thiophene methanol with methacryloyl chloride. The methacrylate monomer was polymerized by free‐radical polymerization in the presence of azobisisobutyronitrile as the initiator. Graft copolymers of poly(3‐methylthienyl methacrylate) (PMTM2) and polypyrrole and of PMTM2 and polythiophene were synthesized by constant‐potential electrolyses. p‐Toluene sulfonic acid, sodium dodecyl sulfate, and tetrabutylammonium tetrafluoroborate were used as the supporting electrolytes. PMTM2‐coated platinum electrodes were used as anodes in the polymerization of pyrrole and thiophene. Moreover, the oxidative polymerization of poly(3‐methylthienyl methacrylate) (PMTM1) was studied with FeCl3 as the oxidant. The self‐polymerization of PMTM1 was also investigated by galvanostatic electrolysis both in dichloromethane and in propylene carbonate. The structures of PMTM1 and PMTM2 were investigated by several spectroscopic and thermal methods. The grafting process was elucidated with conductivity measurements, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermogravimetric analysis, and scanning electron microscopy studies. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4131–4140, 2002  相似文献   

11.
The copolymerization behavior of the one‐step direct polycondensation of 3,5‐bis‐(4‐aminophenoxy)benzoic acid (AB2 monomer) and 3‐(4‐aminophenoxy)benzoic acid (AB monomer) was investigated by IR and 13C NMR measurements. IR measurements revealed that the content of the AB2 units in the polymer was higher in the early stages of polymerization. 13C NMR spectra of the polymers indicated that the number of dendritic units increased slowly with increasing reaction time. The stepwise copolymerization of the AB2 and AB monomers was also carried out, and the structure was analyzed by 13C NMR measurements. Copolymer synthesized stepwise by adding AB2 monomer first (polymer II ) had more dendritic units and less terminal units as compared with the one‐step copolymer (polymer I ). Copolymer synthesized stepwise by adding AB monomer first gave a resulting copolymer (polymer III ) composed of long AB chains. The solubility of the stepwise copolymers was low, and the inherent viscosity was high in comparison with the one‐step copolymer as a result of the difference in architecture of the copolymers. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 3304–3310, 2001  相似文献   

12.
The poly(methyl methacrylate)‐b‐poly(2‐[[[[2‐(perfluorohexyl)]‐sulfonyl]‐amino]ehthyl] methacrylate) (PMMA‐b‐PC6SMA) copolymers were successfully synthesized for the first time using activator regenerated by electron transfer atom transfer radical polymerization (ARGET ATRP) method. Under optimized reaction conditions, the degree of polymerization (DP) of resulting copolymers increased approximately linearly with monomer conversion. Structures of a well‐defined block copolymer were determined by GPC, FT–IR, and 1H‐NMR spectra. Results from AFM and contact angle measurements of polymer films revealed the presence of block segments derived from PC6SMA, as indicated by the obvious increase in hydrophobicity and oleophobicity. The relationship between surface composition and surface wetting ability was confirmed by XPS and AFM spectra. Compared with the random copolymer PMMA‐co‐PC6SMA, C6SMA dosages in the PMMA‐b‐PC6SMA copolymers were greatly decreased, which retained its hydrophobic and oleophobic properties. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2040–2049  相似文献   

13.
We describe the synthesis of three novel thermoresponsive copolymers of acrylonitrile (AN) with N‐isopropylacrylamide (NIPAM) by a combination of reversible addition‐fragmentation chain transfer (RAFT) polymerization and atom transfer radical polymerization (ATRP). Linear copolymer polyacrylonitrile (PAN)‐b‐PNIPAM was directly prepared by RAFT polymerization. Comb‐like copolymers were synthesized by ATRP using brominated AN/2‐hydroxyethyl methacrylate copolymers as macroinitiators, which were prepared by RAFT polymerization. FT‐IR, NMR, and GPC were employed to characterize the synthesized copolymers. Results indicate that the polymerization processes can be well controlled and the resultant copolymers have well‐defined structures as well as narrow polydispersity. Then dense films were fabricated from these thermoresponsive copolymers and the surface wettability was evaluated by water contact angle measurements at different temperatures. It is found that the surface wettability is temperature‐dependant and both the transition temperature and decrement of water contact angle are affected by the copolymer shapes as well as the length of PNIPAM blocks. Considering the excellent fiber‐ and membrane‐forming properties of PAN‐based copolymers, the obtained thermoresponsive copolymers are latent materials for functional fibers and membranes. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 92–102, 2009  相似文献   

14.
This study applied the macromonomers and glycidyl methacrylate (GMA) to synthesize a series of the graft copolymers, poly(GMA)‐graft‐poly(Z‐L ‐lysine), and investigated the conformation of the graft copolymer. The graft copolymers were synthesized with different GMA monomer ratios (28 to 89%) and different degrees of polymerization (DP) (8 to 15) of the poly(Z‐L ‐lysine) side chain to analyze secondary structure relationships. Atomic force microscopy (AFM), Fourier transform infrared spectroscopy (FTIR), and both wide angle and small angle X‐ray scattering spectroscopy (WAXS, SAXS) were used to investigate the relationship between the microstructure and conformation of the graft copolymers and the different monomer ratios and side chain DP. In AFM images, n8‐G89 (the graft copolymer containing 89% GMA units and the macromonomer DP is 8) showed tiny and uniform rod‐like structures, and n14‐G43 (the graft copolymer containing 43% GMA units and the macromonomer DP is 14) showed uniform rod‐like structures. FTIR spectra of the graft copolymers showed that the variations of α‐helix and β‐sheet secondary structures in the graft copolymers relate to the monomer ratios of the graft copolymers. However, the X‐ray scattering patterns indicated that the graft copolymer conformations were mainly dependent on the poly(Z‐L ‐lysine) side chain length, and these results were completely in accordance with the AFM images. © 2009 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 47: 4655–4669, 2009  相似文献   

15.
Three low bandgap polyfluorene copolymers containing a donor–acceptor–donor moiety have been synthesized via Suzuki and Stille polymerization reactions. Their bandgaps and molecular energy levels (highest occupied molecular orbital and lowest unoccupied molecular orbital) varied with different polymerization methods. The molecular weight of the copolymer increased significantly through copolymerizing with a monomer having a long alkyl side chain. In order to investigate their photovoltaic properties, polymer solar cell devices based on the copolymers were fabricated with a structure of indium tin oxide/poly(styrene sulfonic acid)‐doped poly(ethylene dioxythiophene)/copolymers:[6,6]‐phenyl‐C61‐butyric acid methyl ester (PCBM)/LiF/Al under the illumination of AM 1.5G, 100 mW/cm2. We found that the annealing temperature had a profound effect on the power conversion efficiency (PCE) of the devices with a blend of poly[9,9‐didodecylfluorene‐alt‐(bis‐thienylene) benzothiadiazole] (PF12‐TBT) and PCBM. The PCE of the solar cell based on PF12‐TBT/PCBM (1:4) annealing at 70 °C for 20 min was 4.13% with an open‐circuit voltage (Voc) of 1.02 V, fill factor of 55.9%, and a short‐circuit current (Jsc) of 7.24 mA/cm2. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011  相似文献   

16.
A series of novel side‐chain sulfonated poly(arylene ether sulfone) (SPAES) multiblock and random copolymers were synthesized by condensation polymerization from a new disulfonated aryl sulfone monomer, 4,4′‐difluoro‐2,2′‐bis(3‐sulfobenzoyl)diphenyl sulfone disodium salt (DFBSPS). The chemical structures of DFBSPS and the SPAESs were characterized by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FTIR) spectra. The SPAES membranes prepared by solution cast method exhibited high tensile strength (50–71 MPa) and high radical oxidative stability. They could keep their morphology and maintain proton conductivities after hydrolysis test in 95 °C water for 1000 h. They also showed smaller swelling ratio in in‐plane direction than in through‐plane direction and such an anisotropic effect was more significant for the multiblock copolymers than for the random ones. The multiblock copolymer membranes exhibited higher proton conductivity than the random ones with similar ion exchange capacities (IECs). Preliminary hydrogen‐oxygen fuel cell tests were performed at 60 °C and 80% relative humidity (RH). The results showed that the single cell equipped with the multibiock copolymer membrane SB3 exhibited 0.12 W cm?2 higher maximum output power density than the one equipped with the random copolymer membrane SR3 (with the same IEC), indicating much better performance of the former. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2304–2313  相似文献   

17.
The paper presents the electrostatic charge dissipative (ESD) properties of the conducting copolymers of aniline (AN) and 1‐amino‐2‐naphthol‐4‐sulfonic acid (ANSA) blended with low‐density polyethylene (LDPE). The copolymers of aniline and ANSA were synthesized under different reaction conditions. Blending of copolymers with LDPE was carried out in twin screw extruder by melt blending method by loading 0.5 and 1.0 wt% of the conducting copolymer in LDPE matrix. The mechanical properties of the blended films depend on the incorporation of copolymer in the LDPE matrix. The morphology of copolymer–LDPE blend was studied by scanning electron microscopy. The conductivity of the blown film of poly(AN‐co‐ANSA)/LDPE blend was found to be in the range of 10?6–10?11 S/cm, showing its potential use as antistatic bag for the encapsulation of electronic equipments. The static decay time of the film was found to be of the order of 0.1–1.9 sec on recording the decay time from 5000 to 500 V. Static charge measurements carried out on the films show that no charge is present on the surface. The level of interaction between the copolymers and the matrix polymer was determined by the FTIR spectra, blend morphology, electrical conductivity, and thermal analysis. The effect of the morphology on electrical and antistatic behavior of copolymers has also been investigated. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

18.
Amphiphilic graft copolymers were prepared via the radical copolymerization of poly(ethylene oxide) (PEO) macromonomers with fluorocarbon or hydrocarbon acrylates in toluene with 2,2′‐azobisisobutyronitrile (AIBN) as an initiator. 1H NMR spectroscopy confirmed that the composition of the graft copolymers corresponded well to the monomer feed. For gel electrolytes prepared from the amphiphilic copolymers, the nature of the ionophobic parts of the amphiphilic graft copolymers had a great influence on the ion conductivity. Gel electrolytes based on graft copolymers containing fluorocarbon side chains showed significantly higher ion conductivity than electrolytes based on graft copolymers containing hydrocarbon groups. The ambient‐temperature ion conductivity was about 2.6 mS/cm at 20 °C for a gel electrolyte based on an amphiphilic graft copolymer consisting of an acrylate backbone carrying PEO and fluorocarbon side chains. Corresponding gels based on graft copolymers with PEO side chains and hydrocarbon groups showed an ambient‐temperature ion conductivity of about 1.2 mS/cm. The gel electrolytes contained 30 wt % copolymer and 70 wt % 1 M LiPF6 in an ethylene carbonate/γ‐butyrolactone (2/1 w/w) mixture. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2223–2232, 2001  相似文献   

19.
Homopolymers of tbutyl acrylate (PtBuA) and a monosubstituted acrylamide (PAM) having an amino acid moiety in the side chain, N‐acryloyl‐(L )‐phenylalanine methyl ester 1 , have been synthesized by Reversible Addition‐Fragmentation Chain Transfer (RAFT) polymerization. Diblock copolymers of these homopolymers were also synthesized by chain extending PtBuA with monomer 1 and after modification, using simple acid deprotection chemistries of the acrylate block to afford a poly (acrylic acid) block, an optically active amphiphilic diblock copolymer was isolated. The optically active amphiphilic diblock copolymers, which contain chiral amino acid moieties within the hydrophobic segment, were then self‐assembled to afford spherical micelles which were subsequently crosslinked throughout the shell layer to afford robust chiral nanoparticles. The hydrodynamic diameters (Dh) of the block copolymer micelles and nanoparticles were measured by dynamic light scattering (DLS) and the dimensions of the nanoparticles were determined using tapping‐mode atomic force microscopy (AFM) and transmission electron microscopy (TEM). © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 3690–3702, 2008  相似文献   

20.
We report the synthesis of a water‐soluble diblock copolymer composed of polysulfonic diphenyl aniline (PSDA) and poly(ethylene oxide) (PEO), which was prepared by reacting an amine‐terminated PSDA and tosylate PEO (PEO‐Tos). First, a HCl‐mediated polymerization of sulfonic diphenyl aniline monomer with the formation of HCl‐doped PSDA was carried out. After its neutralization and reduction, a secondary amine‐functionalized PSDA was obtained. Second, PEO‐Tos was synthesized via the tosylation of the monohydroxyl PEO methyl ether with tosylol chloride. Diblock copolymers with various PEO segment lengths (PSDA‐b‐PEO‐350 and PSDA‐b‐PEO‐2000) were obtained with PEO‐350 [number‐average molecular weight (Mn) = 350] and PEO‐2000 (Mn = 2000). The prepolymers and diblock copolymers were characterized by Fourier transform infrared spectroscopy, NMR, mass spectrometry, and ultraviolet–visible light. They had relatively low conductivities, ranging from 10?6 to 10?3 S/cm, because of the withdrawing effect of the sulfonic group as well as the steric effects of the bulky aromatic substitutuents at the N sites of the polyaniline backbone and of the PEO block. These polymers were self‐doped, and an intermolecular self‐doping was suggested. The external doping was, however, more effective. The self‐doping induced aggregation in water among the PSDA backbones, which was also stimulated by the presence of hydrophilic PEO blocks. Furthermore, the electrical conductivities of the diblock copolymers were strongly temperature‐dependent. PSDA‐b‐PEO‐2000 exhibited about one order of magnitude increase in conductivity upon heating from 32 to 57 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2179–2191, 2004  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号