Poly Anthranilic Acid

Anthranilic acid (o-amino benzoic acid) is an important monomer for the synthesis of carboxylic acid group-substituted PANI (Fig. 6.15). Studies on the synthesis of poly(anthranilic acid) (PANA) from an aqueous acidic solution are scarcely reported in the literature, probably because of difficulty in synthesis, poor yield, and brittle nature of the film due to presence of an electron-withdrawing carboxylic group. PANA reveals high solubility in an aqueous solution of NaOH or NMP. Similar to poly(metanilic acid), PANA exhibits electrochemical activity over a wide pH range in aqueous solutions owing to the substitution of the carboxylic acid group. 

In addition, self-doped PANI (Fig. 6.17) has an extended pH range of electrical conductivity and electrochemical activity, covering that of many biocatalysts and sensors.  

The limits of PANI applications in electrochemistry arise from the pH dependence of its conductivity. At pH 4.0, PANI becomes electrochemically inactive. Incorporation of the acidic groups like carboxylic and sulfonic acids as ring substituents influences 

Different amounts of PANA were dissolved homogeneously in 10 mL DMF containing 0.5 g polyacrylonitrile (PAN) with enough viscosity for electrospinning. PAN solutions (without any PANA) were prepared and characterized to indicate the differences between PANA/PAN blends prepared by changing amounts of PANA (0.05 g, 0.075 g, and 0.1 g).i  

A composite solution containing different amounts of PANA was followed by UV-Vis spectroscopy in a DMF solution of nanofibers of PANA/PAN blends. The spectra consist of bands with the maxima located at about 536 and 370 nm. These peaks are characteristic for PANA absorption and confirm the presence of PANA in the nanofibers.  

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Golshaei R, Guler Z., Unsal C., and Sarac A. S., In situ spectroscopic and electrochemical impedance study of gold/poly (anthranilic acid) core/ shell nanoparticles, Eur. Polym.]., 2015,66,502-512. 

Dash M. R, Tripathy M., Sasmal A, Gourang C., Mohanty C., and Nayak P. L., Poly anthranilic acid/multi-walled carbon nanotube composites spectral, morphological, and electrical properties,/ Mater. Sci, 2010, 45,3858-3865. 

Nateghi M. R. and Borhani M., Preparation, characterization and application of poly anthranilic acid-co-pyrrole. React. Funct Polym, 2008,68,153-160. 

S. Patra, N. Munichandraiah, Insoluble poly(anthranilic acid) confined in nafion membrane by chemical and electrochemical polymerization of anthranilic acid, Synthetic Metals 2005,150, 285. 

Ext ive investigations on polyaniline (PAn) and its derivatives have be carried out (i) since they possess a moderate conductivity upon doping with protonic acid and an excellent stability under ambient conations (2,3). PAn is simply prepared by the chemical and electrochemical oxidation of aniline or its derivatives in aqueous solution. In general, however, the chemical and electrochemical polymerization of aniline monomer lead merely to an insoluble powder and a thin brittle film, respectively. Hence, it is very difficult to process PAn for a practical use. In order to deal well with this problem, the improvement of processability of PAn has been studied by preparing polymer composites (4) and soluble PAn (5,6) and using plasma polymerization (7) and postsulfonation of PAn (8,9). Another approadi to the preparation of processible PAn is to apply a precursor polymer, e.g., PAn can be produced by the thermal treatment of poly(anthranilic acid) 0 ANA) (10). This mefliod is particularly useful for the preparation of processible PAn or its composites with other insulating polymers since it does not use external dopants that often cause an inconvenient situation associated with a practical use of the conducting polymer. 

Toshima et al. [63] have reported the formation of polyaniline film by decarboxylation of poly(anthranilic acid). The polyanthranilic acid was prepared by using ammonium peroxy disulfate as an oxidizer as described by Chan et al. [64]. The typical reaction can be written as... 

Pblyaniline can also be obtained by decarboxylation of poly-(anthranilic acid) [1030]. Pofy(anthranilic acid) was prepared by... 

Ind 1953, 1179-80 drew attention to previous reports on expl nature of the reaction betn certain diazotized substituted benzenes and Na poly sulfides and stated that not all the reactions lead to the formation of such compds. For example, when diazotized anthranilic acid was treated with Na polysulfide (as in common use in... 

Some sensitive methods for determining uranium are based on ion-associates consisting of anionic uranium(VI) complexes and basic dyes such as Brilliant Green and Crystal Violet [118], Rhodamine B [119], Butylrhodamine B [120], Malachite Green [ 121], Brilliant Green [122,123]. In the methods based on anthranilic acid with Rhodamine 6G [124], or thiocyanate with Rhodamine B [125] the associates formed are not extracted, but the absorbance is measured for aqueous pseudo-solutions, protected with gelatine or poly(vinyl alcohol). 

Finally, we mention some other attempts that have been directed toward the preparation of copolymers poly(aniline-co-o//w-toluidine) [732, 733], poly(aniline-cothiophene) [734], poly(aniline-co-aniline with sulfonate, alkylsulfonate, carboxy-late, chloro and fluoro groups) [735], poly(aniline-co-/7-phenylene diamine) [737], poly(aniline-co-w-phenylenediamine) [736, 738], poly(aniline-co-diphenyl-amine) [164,360,739], poly(aniline-co-dithioaniline [740], as well as copolymers of diphenylamine and anthranilic acid [361] or benzidine [349], iV-vinylcarbazole and thienylpyrrole and terthiophenes [618], and aniline with aminonaphthalenesul-fonates [243]. Several other works that describe copolymers can be found among... 

M. T. Nguyen, A. F. Diaz, Water-soluble poly(aniline-co-o-anthranilic acid) copolymers, Macromolecules 1995, 28, 3411. 

L. Jiang, Q. J. Xie, L. Yang, X. Y. Yang, S. Z. Yao, Simultaneous EQCM and diffuse reflectance UV-Visible spectroelectrochemical measurements poly(aniline-co-o-anthranilic acid) growth and property characterization, Journal of Colloid and Interface Science 2004, 274,150. 

L. Gu et al developed a boronic acid functionalized poly(aniline-co-anthranilic add) MIP composite and used it for the determination of dopamine through impedance spectroscoy. They innovated the introduction of aminophenylbo-ronic acids and vinyl groups onto the surface of poly(aniline-co-anthranilic acid) nanomaterials, before copolymerization of acrylamide and ethylene glycol dimethacrylate... 

L. Gu, X.Y. Jiang, Y. Liang, T.S. Zhou and G.Y. Shi, Double recognition of dopamine based on a boronic acid functionalized poly(aniline-co-anthranilic acid)-molecularly imprinted polymer composite. Analyst, 138 (18) 5461-5469,2013. 

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