The results of investigation of the degradation process of polystyrene brominated on the ring via an ionic route have been
presented. Using thermogravimetric (TG) and differential thermal analysis (DTA) methods, the course of degradation of polymer
samples with different bromine content has been described. Introducing of bromine on the aromatic ring influenced the initial
decomposition temperature (IDT) and the temperature corresponding to the maximum of decomposition rate (Tm).
The samples have been pyrolyzed at 300°C and some pyrolysis products were identified by means of gas chromatography/mass spectrometry.
Finally, the possible mechanism of degradation was presented.
The paper deals with the characterization of three hydrazinic complexes with Ni, Cu and Cr respectively, by means of non-isothermal
thermal methods, TG, DTG and DTA, under nitrogen atmosphere in order to investigate the structure-thermostability-thermal
degradation mechanism correlation. The thermal analysis made evident the degradation mechanisms characteristic of every sample
in accordance with the chemical structure. The quantitative analysis by TG-DTG afforded the estimation of the metal amount
in the complex on the basis of the resulting metallic oxide nature as well as of some aspects of the thermal degradation mechanism
supported by mass spectral measurements. The melting points given by DTA and confirmed by the Boetius method and the initial
temperatures of thermal degradation from TG-DTG-DTA afforded to ascertain the temperature range proper for using and storing
the complexes under study which show potential practical applications as drugs.
one of the most flammable materials, was treated with various compounds containing
nitrogen, phosphorus, halogens, and boron. For a study of flame retardance
from the standpoint of thermal degradation, the samples were subjected to
thermogravimetry (TG), differential thermal analysis (DTA) and differential
thermogravimetry (DTG) in nitrogen to determine if there were any characteristic
correlations between thermal degradation behaviors and the level of flame
retardance. From the resulting data, kinetic parameters for different stages
of thermal degradation are obtained using the method of Broido. The energies
of activation for the decomposition of samples are found to be from 72 to
109 kJ mol–1. For wood and modified wood,
the char yields are found to increase from 10.2 to 30.2%, LOI from 18 to 36.5,
which indicates that the flame retardance of wood treated with compounds is
improved. The flame retardant mechanism of different compounds has also been
The Mg-, Ca- and Ba-salts of poly(itaconic acid) (PIA) were prepared by treating the aqueous solution of the polyacid with
the corresponding metal oxide or hydroxide. The resulting polysalts were analysed by FTIR spectroscopy and thermogravimetry.
The results indicate that the polysalts are thermally more stable than the parent PIA, they all degrade in a similar manner,
the Ba-salt being the most stable.
In this research, the effects of zinc stearate addition on paraffin wax degradation were investigated by differential scanning
calorimetry (DSC) and thermogravimetry (TG). The apparent activation energies of wax decomposition in nitrogen and air atmospheres
were determined as 76 and 37 kJ mol−1, respectively applying Kissinger method to TG data. The degradation rate constants of paraffin containing zinc stearate (0.1–0.5%)
were found to be almost two times greater than that of paraffin only in air atmosphere. However, zinc stearate did not affect
the rate constants in nitrogen significantly.
The Li-, Na- and K salts of poly(itaconic acid) (PIA) were prepared by treating the polyacid with the corresponding aqueous
hydroxide.The resulting polysalts were analyzed by elemental analysis, FTIR spectroscopy and thermogravimetry. The results
indicate that the polysalts are thermally more stable than the parent PIA, they all degrade in a similar manner and somewhat
more complexly than the poly(methacrylic acid) salts.
The thermal degradation mechanisms of random copolymers of methacrylonitrile (MAN) and styrene (St) have been investigated
by pyrolysis gas chromatography in the temperature range of 358 to 920‡C using a Curie point pyrolyzer (JHP-2) and comparing
results with the results from TG/DTA-FTIR apparatus (SII-6200, JASCO-320). The amount of St monomer from decomposition of
the copolymer is higher than that from P(St) alone; whilst that of MAN monomer from copolymer is lower than that from P(MAN).
This phenomenon reflects the boundary effect in the pyrolysis of copolymer. The thermal degradation mechanisms of copolymers
are discussed in terms of the competition between the depolymerization and the back biting reaction on the basis of bond dissociation
energies of C-C and C-H bonds in the copolymer chain.