Synthesis and characterization of water soluble conducting poly (3-Amino-4-Methoxybenzenesulfonic acid)

Article abstract of DOI:10.1080/15421400801904898

The preparation of conducting water soluble sulfonated polyaniline, poly (3-amino-4-methoxybenzenesulfonic acid), has been investigated. Poly (3-amino-4-methoxybenzenesulfonic acid) has been polymerized via chemical oxidation. Using a dialysis membrane, separation and purification of high molecular weight polymer from low molecular oligomers were carried out successfully. UV-Visible spectroscopy, cyclic voltammetry and four-point-probe conductivity measurements of polymer were recorded. The prepared polymer was conducting and fully water soluble. The conductivity of polymer was about 0.0430-0.75S/cm and it were found that reaction temperature, monomer and oxidant concentration had dramatic effect on conductivity of poly(3-amino-4- methoxybenzenesulfonic acid).

Full text of DOI:10.1080/15421400801904898

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Synthesis and Characterization
of Water Soluble Conducting
Poly (3-Amino-4-
Methoxybenzenesulfonic Acid)
a
Abdolreza Mirmohseni & Mehrdad Rastgouy
a
Houjaghan
a
Polymer Research Technology Laboratory, Faculty
of Chemistry, University of Tabriz , Tabriz-Iran
Published online: 22 Sep 2010.
To cite this article: Abdolreza Mirmohseni & Mehrdad Rastgouy Houjaghan (2008)
Synthesis and Characterization of Water Soluble Conducting Poly (3-Amino-4-
Methoxybenzenesulfonic Acid), Molecular Crystals and Liquid Crystals, 484:1, 356/
[722]-361/[727], DOI: 10.1080/15421400801904898
To link to this article: http://dx.doi.org/10.1080/15421400801904898
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Mol. Cryst. Liq. Cryst., Vol. 484, pp. 356=[722]–361=[727], 2008
Copyright # Taylor & Francis Group, LLC
ISSN: 1542-1406 print=1563-5287 online
DOI: 10.1080/15421400801904898
Synthesis and Characterization of Water
Soluble Conducting Poly (3-Amino-4-
Methoxybenzenesulfonic Acid)
Abdolreza Mirmohseni and Mehrdad Rastgouy
Houjaghan
Polymer Research Technology Laboratory, Faculty of Chemistry,
University of Tabriz, Tabriz-Iran
The preparation of conducting water soluble sulfonated polyaniline, poly (3-
amino-4-methoxybenzenesulfonic acid), has been investigated. Poly (3-amino-4-
methoxybenzenesulfonic acid) has been polymerized via chemical oxidation. Using
a dialysis membrane, separation and purification of high molecular weight
polymer from low molecular oligomers were carried out successfully. UV-Visible
spectroscopy, cyclic voltammetry and four-point-probe conductivity measurements
of polymer were recorded. The prepared polymer was conducting and fully water
soluble. The conductivity of polymer was about 0.0430–0.75 S=cm and it were
found that reaction temperature, monomer and oxidant concentration had
dramatic effect on conductivity of poly(3-amino-4-methoxybenzenesulfonic acid).
Keywords: 3-amino-4-methoxybenzenesulfonic acid; conducting polymers; PMAS;
water soluble polymer
INTRODUCTION
Inherently conducting polymers such as polyaniline and their deriva-
tives have attracted many attentions due to their electrical and optical
properties. The polymers have been used for various applications
including batteries [1], anti-corrosive coatings [2], electromagnetic
shielding [3], rechargeable polymeric batteries [4], polymer photovol-
taics [5] and polymer actuators [6,7]. Most industrial application of
We are gratefully to Dr. A. Oladegaragoze for helpful discussion and experimental
support.
Address correspondence to Abdolreza Mirmohseni, Polymer Research Technology
Laboratory, Faculty of Chemistry, University of Tabriz, P.O. Box 51575-5144, Tabriz-
Iran. E-mail: mirmohseni@tabrizu.ac.ir
3
56=[722]

Conducting p-3-Amino-4-Methoxybenzenesulfonic Acid
357=[723]
conducting polymers are limited due to its low mechanical properties.
They also suffer by poor solution and melt proceessibility.
The use of appropriate dopants, for example, dodecylbenzene sulfo-
nic acid or camphor sulfonic acid, can render the polyaniline salt sol-
uble in some organic solvents such as N-methylpyrrolidone (NMP) or
m-cresol [8,9]. Alternatively the introduction of alkyl (alkyl group on
N substituent) [10,11], alkoxy substituents [12,13], or formation of
graft polymerization polymers [14] renders polyaniline soluble in sol-
vents such as tetrahydrofuran. Such materials are then amenable to
subsequent processing.
A common approach used to improve polyaniline solubility in water
is the introduction of sulfonic acid groups onto the polymer backbone.
This can be achieved by treating the polymer with fuming sulfuric acid
after polymerization or by polymerizing=copolymerizing substituted
aniline derivatives. Introduction of the sulfonate group does have a
dramatic effect on the polymerization process. The strong electron-
with-drawing effect of the –SO H lowers the electron density on the
3
amino groups, making it difficult to obtain polyaniline sulfonic acid
(
PASA) with high molecular weight and high conductivity. In order
to solve this problem a methoxy electron-donating group was substi-
tuted onto the aniline ring to produce 3-amino-4-methoxybenzene-
sulfonic acid.
EXPERIMENTAL
3
-amino-4-methoxybenzenesulfonic acid (MAS) was prepared through
the reaction of dissolved O-Anisidine in sulfuric acid and fuming sul-
furic acid. The temperature range and stirring rate of reaction were
ꢀ
7
5–85 C and 100 rounds per minutes (rpm) respectively. The reaction
carried out in 20 Minutes. Before polymerization of MAS it purified by
acid base crystallization.
The 25 mL of 0.7 M Aqueous MAS solution was prepared. And sol-
ution pH was adjusted to 4.2 using 0.5 M NH OH solution. Then
4
2
5 mL of 1 M Ammonium peroxydisulfate (as oxidant) was added drop
ꢀ
wise to MAS solution while temperature was kept lower than 20 C. The
solution was then stirred at temperature range lower than 20 C under
ꢀ
stirring rate of 100 rpm for a period of 24 hours. The polymer solution
purified with 12 KDa MWCO Sigma dialysis membrane. Dialyzing was
performed in 1 L water 3 times each for 12 hours. Free-standing films of
PMAS were prepared by casting the solution onto a glass slide.
Sulfuric acid, fuming sulfuric acid, O-Anisidine, Ammonium
hydroxide and Ammonium peroxydisulfate were purchased from
MERK Company.

3
58=[724]
A. Mirmohseni and M. R. Houjaghan
INSTRUMENTATION
UV-Visible spectra were recorded by shimdzu UV-1601 UV-Visible
spectrophotometer. Cyclic voltammetry (CV) studies were carried
out using by model 101 cyclic voltammeter (Sahand Pardazan, Tabriz,
Iran) with conventional three-electrode electrochemical cell a glassy
carbon working electrode in combination with platinum mesh and
Ag=AgCl (3 M NaCl) auxiliary and reference electrode, respectively.
four-point-probe conductivity measurements were performed on dried
films.
RESULTS AND DISCUSSION
The UV-Visible spectra of aqueous PMAS (0.1 g=L) exhibits two
absorption bands at 474 nm and around 330 nm (Fig. 1). The peak at
ꢁ
3
30 nm may be recognized as p-p transitions and the peak at
4
74 nm is assigned to a polaron bond.
Cyclic voltammogram (i vs. E) was recorded. The first response
0
(
A=A ) is due to the oxidation of leucoemeraldine form of MAS to emer-
0
aldine form. The response (B=B ) may be attributed to the oxidation of
emeraldine to pernigeraniline form of full oxidized PMAS (Fig. 2). The
FIGURE 1 UV-Visible spectrum of pure PMAS (0.1 g=L).

Conducting p-3-Amino-4-Methoxybenzenesulfonic Acid
359=[725]
FIGURE 2 Cyclic voltammogram obtained for PMAS 0.5 g=L at a glassy
carbon electrode in scan rate of 20 mV=s between ꢂ0.2 and 1.1 V potentials.
solution process ability studies showed that PMAS solution process
ability improved and it is fully water soluble (Table 1).
The study of electrical conductivity with four-point-probe conduc-
tivity measurements at room temperature determined that the con-
ductivity of polymer is about 0.0430–0.75 S=cm and it was found
that experimental conditions such as temperature, monomer and oxi-
dant concentration (Fig. 3) and dialyzed time (Fig. 4) had dramatic
effect on conductivity of PMAS. By evaluation of adhesion, it was
found that PMAS polymer has not high adhesion on glass and metallic
surfaces.
TABLE 1 Improved PMAS Solution Process Ability (The
Maximum Mass of PMAS Which Dissolves in 100 g of a Given
Solvent)
Solvent
Solubility
N-methyl-pyrrolidone
Dimethylformamide
>5
2.5
0
1
,2-dichloroethane
Butyl acetate
Chloroform
Acetone
0.05
0
0
Water
>30

3
60=[726]
A. Mirmohseni and M. R. Houjaghan
FIGURE 3 Effect of monomer concentration on conductivity of PMAS in a low
ꢀ
temperature (below 10 C) and the oxidant=monomer molar ratio of 1.
CONCLUSIONS
Water soluble conductive sulfonated polyaniline can be produced by
chemically oxidation of 3-amino-4-methoxybenzenesulfonic acid by
using ammonium peroxydisulfate. The prepared polymer was conduct-
ing, electro active and fully water soluble. The study of electrical con-
ductivity determined that the conductivity of polymer is about 0.0430–
0
.75 S=cm and experimental conditions such as temperature, monomer
FIGURE 4 Effect of dialyzed time on conductivity of PMAS using a high
ꢀ
concentration of monomer (0.7 M) in a low temperature (below 10 C) and the
oxidant=monomer molar ratio of 1.

Conducting p-3-Amino-4-Methoxybenzenesulfonic Acid
361=[727]
and oxidant concentration had dramatic effect on properties of PMAS.
The higher conductivity (ꢃ0.75 S=cm) were obtained using a high con-
ꢀ
centration of monomer (0.7 M) in a low temperature (below 10 C) and
the oxidant=monomer molar ratio of 1.
REFERENCES
[1] Mirmohseni, A. & Solhjo, R. (2003). European Polymer Journal., 39, 219.
[2] Mirmohseni, A. & Oladegaragoze, A. (2000). Synth. Met., 114, 105.
[3] Joo, J. & Epstein, A. J. (1994). Appl. Phys. Lett., 65, 2278.
[4] MacDiarmid, A. G., Mu, S. L., Somatiri, N. L. D., & Wu, M. (1985). Mol. Cryst. Liq.
Cryst., 121, 187.
[5] Ashassi Sorkhabi, H., Mirmohseni, A., & Asghari, E. (2005). 7th Iranian Physical
Chemistry Seminar, Isfahan8-10 March.
[
[
[
[
6] Herod, T. E. & Schlenoff, J. B. (1993). Chem. Mater., 5, 951.
7] Kaneto, K., Kaneko, M., Min, Y., & MacDiarmid, A. G. (1995). Synth. Met., 71, 2211.
8] Heeger, A. J. (1993). Synth. Met., 55, 3471.
9] Cao, Y., Smith, P., & Heeger, A. J. (1992). Synth. Met., 48, 91.
[
[
[
[
[
10] Yano, J. (1991). J. Electrochem. Soc., 138, 455.
11] Wei, Y., Hariharan, R., & Patel, S. A. (1990). Macromolecules, 23, 758.
12] Aprano, D., Leclerc, G., Zotti, M., & Schiavon, G. (1995). Chem. Mater., 7, 33.
13] Gazotti, W. A. & De Paoli, M. A. (1996). Synth. Met., 80, 263.
14] Li, S., Cao, Y., & Xue, Z. (1987). Synth. Met., 20, 141.