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development, the world of conducting polymers is established as an important branch of material science with many opportunities for applications in electronics and photonics. Conducting polymer/inorganic oxide nanocomposites combine the ambilateral merits to
Thermal analysis of conducting polymers part I
Thermogravimetry of acid-doped polyanilines
Abstract
The title polymer was obtained electrochemically by the reduction of 4,4'-bis(dibromomethyl)-2,2'-dimethoxybiphenyl under very smooth conditions. The DSC and TG/DTG curves registered at four different heating rates showed that the polymer is stable in air up to 150C, where smooth degradation starts. Above 300C, decomposition is fast and exothermic (ΔH= –323 J g–1) . The activation energy (1164 kJ mol–1 ) was determined by Ozawa's method.
Abstract
The thermal behaviour of polyaniline plasticized by an oligoester of phosphoric acid was investigated by means of thermogravimetry, either alone or coupled with Fourier transform infrared spectroscopy, and differential scanning calorimetry. It was found that additional thermal transitions, resulting from the dopant, occur in the temperature range 200-250C. The emission of volatile products, as evidenced by the Gram-Schmidt chromatograms, was suppressed by the plasticizer used. This stabilization was probably due to a decreased possibility of diffusion in the three-dimensional honeycomb polymer-plasticizer structure.
Abstract
Chemical polymerization of pyrrole (Py) was carried out in a reaction calorimeter by using FeCl3 or CuCl2 as an oxidant in an acetonitrile medium. The formation heat of polypyrrole (PPy), determined under a wide range of reactant concentrations and reaction temperatures, is directly related to the PPy yields and to the degree of polymerization. Due to the negative values of both the entropy and enthalpy of the reaction the gravimetric yield is inversely related to the temperature and directly to the Py concentration. The yields to the PPy and the related reaction heats, are close to zero when the 
ceiling temperatures
are reached (T
ceil=348 K for Fe-doped and T
ceil=313 K for Cu-doped PPys). It was observed that a ceiling concentration corresponds to each ceiling temperature and only light oligomers are formed if Py concentration is too low. The electric conductivity values of the products were also determined and a direct relationship to the yields was found as well. The highest electric conductivity value (C=0.6 S cm–1) was related to the PPy fresh synthesized from a 0.017 M Py solution.
Oxidative chemical polymerization of pyrrole
Calorimetric and kinetic measurements
A reaction calorimeter has been used to determine at three different temperatures the enthalpy values for the polymerization of pyrrole dissolved in acetonitrile, by using FeCl3 as the oxidative agent. From the calorimetric data it has been found that the reaction is first-order with respect to the pyrrole. The rate constants at the same temperatures have also been determined. By using the Arrhenius equation we have obtained the activation energy for the formation of this electroconducting polymer.
Abstract
Thermal characteristics of a new thiophene derivative, 2-(thiophen-3-yl-)ethyl octanoate (OTE), its homopolymer (POTE), and copolymer with thiophene P(OTE-co-Th) were investigated via pyrolysis mass spectrometry. Thermal degradation of the copolymer started by lose of side chains and thiophene involving products evolved almost in the same temperature range where PTh degradation was detected, at slightly higher temperatures than PTh backbone decomposed during the pyrolysis of POTE. The extent of doping and network structure decreased in the order POTE<P(OTE-co-Th)<PTh.
Thermal Analysis of Electroactive Polymers based on Aniline and its Derivatives
A comparative study
The thermal characteristics of polyaniline (PANI), poly(o-aminobenzoic acid) (POABAC) and poly(o-aminobenzyl alcohol) (POABOL) are determined and compared by thermogravimetry (TG) and differential scanning calorimetry (DSC). The higher thermal stability of POABOL is attributed to heat-induced condensation between the polymer chains. The DSC results suggest both intra- and inter-molecular interaction in the form of hydrogen bonding due to the substituent group in POABAC and POABOL. These interactions, however, occur mainly in the doped from and is greatly reduced when the dopant is expelled from the system at higher temperatures.
Abstract
The synthesis of conducting polymers based on m-nitroaniline, m-chloroaniline and m-aminophenol by aniline initiated ammonium peroxydisulfate oxidation, has been attempted. The IR spectra of the polymers have been studied. Thermogravimetric analysis of the conducting polymers has been followed using a computer analysis method LOTUS PACKAGE, developed by us for assigning the degradation mechanism. A number of equations have been used to evaluate the kinetic parameters. The mechanism of degradation of the conducting polymers has been explained on the basis of their kinetic parameters.
Abstract
The influence of 
-radiation on the structure of Langmuir-Blodgett (LB) layers of poly (3-hexadecylthiophene) in mixtures containing stearic and linolenic acids has been studied. The action of -photons leads to structural changes in the conducting polymer backbone as well as to disrupting oriented LB film structures.
