The effect of synthesis conditions on the properties of polyaniline film

Synthetic

ELSEVIER

The effect of synthesis

Metals

conditions

69 (1995)

on the properties

S. M. Yang Dept.

of Chemical

153-154

of polyaniline

film

and J. T. Chen

Engineering,

National

Chung-Li,

Central

University

Taiwan

Abstract The

effect

of oxidant

oxidation

state,

solubility

(ammonia in NMP

persulfate)/aniline

and the properties

ratio

(APS/An)

and reaction

of the films made from

INTRODUCTION

formation

NMP

The

free standing solution

reported

to be 350

[l].

synthesis

The

of polyaniline synthesis

film of polyaniline

and stretch s cm-l

along

conditions

may

film.

on the

can be casted

The

from

conductivity

the stretched influence

In this study,

conditions

polyaniline

aligned.

direction

the effect

and

properties

purple higher

of

from

the

clean glass. soaking was

NMP

Infrared

with

were measured Molecular

410 gel permeation

RESULTS

of base

AND

form

in HCl Film was

on a piece

film can be easily peeled

in an oven

spectra

of aniline

peroxydisulfate.

for five minutes.

spectrophotometer. Waters

solution

The polymer

in water

stretched

by oxidation

with ammonium

The

film

FT-40

FTIR

was determined

by a

degree

DISCUSSION

The

yield

creasing posed

of

up to

polyaniline 1.25

and

of APS/An. by Wei

and

aniline

polymerization. monomer

ization

this path,

enough

involves

are lost during APS/An

One path

to the dimer,

electrons

dine, emeraldine path

to the

[2],

there

APS/An

and pernigraniline, the formation

of dimer

0

mechanism the

enough

pro-

paths

of

addition

of

If polymer1 and 1.25

will

of leucoemeral-

respectively. units.

in-

are lost during

tetramer. = 0.75,

increasing further

are two

Four

of a leucoemeraldine

= 0.5, 0.75 and 1 provides

0379-6779/95/$09.50

with

involves

for the formation

the coupling

with

six electrons

of a leucoemeraldine

follows

provide

decreases

According co-workers

aniline

the formation

increases

then

The other

of oxidation The

represent

the

structure

and N-B-N

[3].

APS /An

The degree <

and

>

1.25.

tion involves

stage,

after

no extra

other

than

the ratio

state

of the polymer the

The

weight

calibrated

average

to higher

ratio.

The

change

from

1 to 2.

weight

to

remaining

in the higher

ox-

increases

with

increases

with

and higher solubilities

a maximum

is around

130,000

The peak maximum

with increasing

significant

High oxidant

The reach

weight

standard.

is especially

were

der in NMP

<

exposure

irrespective 1.25,

of oxidation

molecular

molecular

effect

obtained.

>

of oxidation

The degree

APSJAn

by the oxidant After

chains

state is re-

temperature.

with polystyrene

shifted

When

APS /An

keep some

reaction

APSJAn

oxidation

is formed

state,

APS /An.

increasing

of aniline polymeriza-

state.

oxidant increasing

respec-

the same when

is provided

degree

Q is quinoid

structure,

of pernigraniline. While

in incm-’

to air the polymer

idation

increasing

where

with

power

oxidation

and

and 1500

process

oxidation

the formation of APSJAn.

cm-’

of pernigraniline

oxidizing

by the ratio

1500 cm-’

remains

exposure

to the emeraldine

1.25,

ing of the polymer

1995 Elsevier Science S.A. All rights reserved

SSDI 0379-6779(94)02399-J

The

the yield

mechanism.

B is benzoid

increases

the formation

in the early

the higher

of N=Q=N

This

for higher

versus

at 1600

of oxidation

1.25

electrons for the

color of the filtrant polymerization

where

For

into oligomers

can be represented

stretching

for

< 1.25.

degredates

peaks

spectra.

the pern-

is the reason

and lost upon filtration.

frared

tetramer.

electrons

the polymer

of 1600 cm-’

tively

indicating That

with APSJAn

in solution

with the radical

to air emeraldine

APS/An

APS/An

of the peak intensity

duced

chromatography.

of oxidant is formed.

and pernigrani-

turns into pink and

The lower the temperature,

when APSJAn

programmer.

with a Digilab weight

off after

free standing

temperature

of

mixture

by the more intense

agrees

The was formed

state

at higher

is evident

EXPERIMENTAL

made

yield

APSJAn.

solution

addition

which are dissolved

film.

Polyaniline

upon

oxidation

of

that

aqueous

color

igraniline

emeraldine

The reaction

even higher APS /An,

the properties

we report

preparation

was

on the yield,

were studied.

of leucoemeraldine,

line, respectively.

NMP

temperature

solution

ratio

when induces

molecular of dry

weight

APS /An APSJAn crosslinkproducts

polyaniline

at APSJAn

=

1.25.

powThe

154

SM. Yang, J.T. Chen I Synthetic Metals 69 (1995) 153-154

solubilities higher ers

of the

than

[3] study

soluble part

samples

the sample the

parts

Raman

lA-like

phenylenediamine

the

units,

ferent

ordering

units.

When

APS/An

with

increasing

units

the

for the sample

>

that

the degree

APS/An

and

This

may result

ple formed about

from

between

the displacement The (l/lo) 1.

films

Elongation

APS/An

plotted

decreases

with

and

thesized

at 20°C

synthesized

at

weight

and

is much

higher

oxidation

of the

samples

ature

to the

less

leads

higher

than

NMP

solution

1.75,

line films were stretched lower and reaction

of polyaniline.

to higher

temperature

1.25.

ratio

is -5’C

be

The polyani-

when

APS/An

is

and O’C.

from

film. hardly

samples

than

the

samples

higher

degree

Figure

of polyaniline

films

temperature

REFERENCES

the

1. A. P. Monkman

Commun.,

Syn.

Y. Sun and W.

Met.,

Focke,

41 (1991), J. Polym.

627 Sci.,

2385. A. Ohtani,

H. Higuchi, when APS/An

and P. Adams,

X. Tang,

27 (1989), 3. M. Abe, a maximum

and synthesis

is

2. Y. Wei,

reach

of the elongation

of

temperfrom

1. The variation with APS/An

APS/An

be formed

2.0

kitio

ac-

molecular

When

‘Aolar

syn-

lower at higher

APS/An

When

increases

The

0.5

0.0

in figure

APS/An.

hence

was

Elongation

APS/An

The

synthesized can

are tem-

solution

oven.

stretched state

of the sam-

are miscible,

NMP

decreases. less

formed

of polyaniline.

of polyaniline

lower than

the film can hardly

at 20’ C.

CONCLUSION The yields

solution

1.75,

is much easier.

of crosslinking

stretched

the film

than

ring are the same

APS/An

the interaction

and water

temperature.

crosslinking

with

is higher

from the NMP

and quinone

at

and O’C.

SEM

and synthesis

increasing

the degree

lower

state

against

the elongation

formed

APS/An

of -5’C

in-

of the wet samples

temperature

are

increases,

cordingly

NMP

casted

in a controlled

of the

formed

oxidation

by NMP

film of polyaniline

When

ring

synthesized

sol-

of the solvent

of water decreases

of water

dif-

of benzoid

temperatures

The

a maximum

was observed

of the samples

to APS/An

chains.

1.25,

the

ratios

for polyaniline

also reach

to the lower sol-

than the sample

A small amount

of The

accordingly.

volume

solubilities

irrespective

The

is -5“C.

temperature form

quinonediimine

Penetration

The solubilities

the polymer

stretched

void

the higher

at 2O’C.

the same

perature.

decrease

PAS/An. The

soluble

of oxidation

the

which may also contribute

of the sample.

of 1.25 and reaction

of p-

base

and p-phenylenediamine

1.25,

at 0“ C and -5” C are higher

APS/An

<

from

and reaction

and in-

consists

APS/An

to 1.25

of polyaniline

units.

result

equals ubi!ities

that

part

when

may

smaller

of lower

is more difficult, ubility

the same

are

is composed

p-phenylenediamine

solubilities

show

soluble

insoluble

solubility

-5’C

and cowork-

concluded

of quinonediimine

increase,

photographs

Abe

which

while

are

of the

0’ C and

of NMP

and

and

of oxidation

differences

creases

spectra

structure,

quinonediimine

degrees

at

at 2O’C.

of polyaniline,

contains

both

formed

formed

Y.

K. Nakamoto, (1989),

1736.

Umemoto, A. Okuno

S. Akizuki,

M. Ezoe,

and Y. Noda,

Chem.