Thermal properties of poly(anthranilic acid) (PANA) and humidity-sensitivecomposites derived from heat-treated PANA and poly(vinyl alcohol)

Citation
K. Ogura et al., Thermal properties of poly(anthranilic acid) (PANA) and humidity-sensitivecomposites derived from heat-treated PANA and poly(vinyl alcohol), J POL SC PC, 37(23), 1999, pp. 4458-4465
Citations number
23
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Organic Chemistry/Polymer Science
Journal title
JOURNAL OF POLYMER SCIENCE PART A-POLYMER CHEMISTRY
ISSN journal
0887-624X → ACNP
Volume
37
Issue
23
Year of publication
1999
Pages
4458 - 4465
Database
ISI
SICI code
0887-624X(199912)37:23<4458:TPOPA(>2.0.ZU;2-5
Abstract
Thermal conversion of poly(anthranilic acid) (PANA) to polyaniline (PAn) ha s been studied by means of thermogravimetric/mass (TG/MS) and Fourier trans form infrared (FTIR) spectroscopy. The electrical conductivity of the chemi cally prepared PANA was 3.5 x 10(-2) S/cm, which is caused by the self-dopi ng of the polaronic nitrogen atom interacting with the ionized carboxyl gro up (-COO-). The heat-treated PANA can be assumed to be identical to an emer aldine base of PAn. The pyrolysis of PANA. proceeded through the decarboxyl ation at two stages from carboxyl (-COOH) and ionized carboxyl groups, whic h occurred at about 170 and 230 degrees C, respectively. PANA-SA, which was prepared by treating PANA at 250 degrees C and then doping with an externa l protonic acid at room temperature, showed a considerably high conductivit y (6.2 S/cm). The composite consisting of PANA-SA and poly(vinyl alcohol) w as very sensitive to the environmental humidity. The logarithm of electrica l conductivity of this composite was proportional to the relative humidity covering more than five orders of magnitude, and the change in conductivity extended from 4.2 x 10(-5) to 10 S/cm upon the humidity variation from 14 to 91%. (C) 1999 John Wiley & Sons, Inc.