ABSTRACT:Sulfonated polyaniline has been synthesized by a novel method, in which p-aminodiphenylamine (p-APA) and o-aminobenzenesulfonic acid (o-ABS) are copolymerized. The copolymers produced have the same composition even though the feed ratios (p-APA/o-ABS) are varied. This fact as well as the results of elemental analysis, infrared (IR), ultraviolet-visible (UV-Vis), 1 H nuclear magnetic resonance (NMR), and X-Ray photoelectron spectroscopic (XPS) spectra show that the copolymer has a so-called one-to-one structure of p-APA and o-ABS. XPS spectra reveal that three kinds of nitrogen atoms exist in the copolymer, namely, amine nitrogen, radical cation type nitrogen, and iminium ion type nitrogen. One third of the whole nitrogens is self-doped. Conductivity of the copolymer is independent of pH, but lower than that of doped polyaniline probably because of the presence of sulfonyl acid groups. The copolymer is soluble in an aqueous alkaline solution owing to sulfonyl acid groups. Electronic spectra of the mixtures of p-APA and o-ABS suggest that the 1: 1 charge-transfer complex is formed between p-APA and o-ABS. Oxidizing agents are considered toreact with the charge-transfer complex to form the one-to-one copolymer of p-APA and o-ABS.KEY WORDS Water-Soluble Conductive Polymer I Self-Doped Sulfonated Polyaniline I p-Aminodiphenylamine I o-Aminobenzenesulfonic Acid I Charge-Transfer Complex I Copolymer I Good Processability I Among the aromatic conductive polymers such as polyacetylene, polythiophene, polyaniline, and polypyrrole, polyaniline has been most successfully applied to practical use, since it is stable under air and soluble in solvents such as N-methyl-2-pyrrolidone (NMP). For example, the applications to antistatic agents, electromagnetic shielding materials, secondary batteries, 1 -3 redox reaction catalysts, 4 -6 gas sensors/ gas separation membranes,8 artificial mascle, 9 etc. have been examined. However, there are still big problems in processability of polyaniline.The attempts to improve processability by means of altering polyaniline into its derivatives by introducing alkyl groups into the aromatic ring and/or the nitrogen site were reported so often. 10 -12 However, this introduction always causes the decrease of electric conductivity in compensation for increase of processability. In the meantime, the precursor method was reported on processing of polyphenylene for the purpose of improving processability. 13 In this method a film of polyphenylene was obtained by heating a film of the precursor having good processability. However, there was no reports on the application of the precursor method to prepare a polyaniline film. Recently we have succeeded in preparing a film ofpolyaniline by heating a cast film ofpolyanthranilic acid which is a soluble precursor of polyaniline.14-15On the other hand, much attention has been paid to sulfonated polyanilines, 16 -34 because it is stable and soluble even into water when self-doped. In a conventional method, sulfonated polyaniline was prepared by the re...
Thermal conductivities of undoped and various protonic acid-doped polyaniline films were measured by combination of a laser flash method and a scanning differential calorimeter. The thermal conductivities thus measured are in the range of conventional organic polymers, indicating that the doped polyaniline films have extremely low thermal conductivities among electrically conductive materials.
ABSTRACT:Donor (or acceptor) poly(carbonate)s or poly(phthalate)s were prepared from 2-(p-dimethylaminobenzyl)-1 ,3-propanediol (or from 2-(3,5-dinitrobenzyl)-1 ,3-propanediol). The spectral, thermal, mechanical, and optical properties were measured for the donor polymers, the acceptor polymers, and their blends in order to clarify the effects of the formed electron-donoracceptor (EDA) complexes. The donor and acceptor polymer blends were found to consist of twophase structures by differential scanning calorimetry, torsional braid analysis, and scanning electron microscopy. It was noticed that the tensile modulus of the polymer blends was larger than that of each component polymer. The increased mechanical strength was interpreted in terms of the EDA interaction on the boundaries between globules and surroundings.KEYIt is well known that the mechanical properties of polymers are much affected by binding forces, such as dispersion force, hydrogen bond, dipole--dipole interaction due to the formation of electron-donoracceptor (EDA) complexes, etc. There have been a few studies on the effects of intermolecular interaction due to the formation of EDA complexes on structure and mechanical properties of polymers.Hallensleven and Kuppel found that the viscosity of poly(4-vinylpyridine) in solution is strongly influenced by added tetracyanoethylene (TCNE). 1 Boudevska eta!. observed the structure formation of complexes of poly(phenyl methacrylate), poly(2-naphthyl methacrylate), and poly(vinylcarbazole) with TCNE, using electron microscopy and X-ray diffraction. with p-chloranil within a high temperature range increases as a result of the formation of physical crosslinking due to the formed EDA complexes in the polymer matrix. 3 Sulzberg and Cotter prepared the acceptor polymers having nitrophthalate units in main chain and the donor polymers from aryliminodiethanols where the aryl was phenyl or p-anisyl, and studied the effects of blending on glass transition temperature, tensile modulus, solution viscosity, etc. 4 This is the first report on the EDA complexes formed by blending donor polymers and acceptor polymers.We have been interested in the blends of donor polymers and acceptor polymers, since certain properties of these complexes may, in future, have promise not only from a mechanical, but also from photoreactive, photoconductive, electrical properties, etc. points of view. Sulzberg et al. used the polymers containing the donor or the acceptor residues in the main chain. We used the polymers possessing pendent-type donor or acceptor groups to strengthen the EDA interaction between the donor and acceptor polymers by decreasing restriction of main chain. Moreover, the structures of donor and acceptor monomers are designed to provide a better compatibility with blends in this study.We prepared 2-(p-dimethylaminobenzyl)-1,3-947
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