A combination of pyrolysis and gas chromatography were used to investigate thermal degradation products formed from acrylic
copolymers containing alkyl acrylate and methacrylate. The method provided an analytical tool for characterizing the chemical
composition and structure of the degradation products. Thermal degradation of the synthesized copolymers was analyzed using
isothermal (250 °C) pyrolysis–gas chromatography. The degradation process, and the nature and amount of pyrolysis products,
provides relevant information about the thermal degradation of acrylic copolymers and the mechanism of pyrolysis. During pyrolysis,
the formation of corresponding olefins, alcohols, acrylates and methacrylate was observed.
Effects of fullerenes including FS, EFS and pure C60 on thermal behaviors of polyethylene glycol (PEG) have been studied by employing thermogravimetry-differential thermogravimetry
(TG-DTG), differential scanning calorimeter (DSC) and off-line furnace-type pyrolysis-gas chromatography/mass spectrometry
(Py-GC/MS). The products were collected by Cambridge filter pad which was widely used in analyzing the combustion products
of cigarette. The results showed that the addition of fullerenes obviously restrained the thermal decomposition of PEG. The
initial decomposition temperatures (IDT) and maximum decomposition peak temperatures (MDT) were evidently postponed by the
addition of fullerenes. Pyrolysis products with one or two hydroxyl end groups obviously increased with the addition of 10%
C60. The reasons of the changes were discussed from the aspects of reaction mechanisms.
TA/MS (thermal analysis coupled with mass spectrometry) was applied to the pyrolysis of Chinese coals with different ranks.
A total of 13 Chinese coals were investigated. The samples were deliberately chosen to represent the 13 types of Chinese coals
according to the Chinese coal classification system. The experiments were carried out in an argon atmosphere with a flow rate
of 150 ml min-1. The samples were heated from 40 up to 1200C with a constant heating rate of 10 k min-1. The main evolved pyrolysis products were identified through the on-line recorded mass spectra. The thermal and evolution
behavior was compared between the coals. The results showed a strong thermal and evaluation behavior dependence on the coal
rank. Different aliphatic fragments and also some aromatic substances, which are of environmental concern (BTX, PAHs), were
found to be released depending on the different types of coal.
Homopolymers of chlorotrifluoroethylene (CTFE), vinylidene fluoride (VDF) and methyl methacrylate (MMA) and their copolymers
were studied by PGC/IR with regard to the separation and identification of the degraded products and clarification of the
degradation mechanism. Besides monomers, HCl CO2, C2H2, HF, C5H10O2, C3F5Cl and dimers are the observed pyrolysis products. Mechanisms for different degradation reactions have also been studied.
The thermal behaviour of three ester derivatives of p-tert-butyl calix[n]arene (n = 4, 6 and 8) in comparison with the parent calixarene was investigated by means of the thermogravimetric (TG) and differential thermogravimetic (DTG) analysis and differential scanning calorimetry (DSC). The thermal stability domains, the composition of the pyrolysis products and the thermal effects, were determined on the basis of TG, DTG and DSC plots registered in nitrogen flow. Attempts to analyse the evolved gases by TG-FTIR coupling were also performed. It was demonstrated that the stability of the calix[n]arene derivatives depends on both the size of the hydrophobic cavity and number of the substituting groups grafted on the calix[n]arene skeleton.
In the present study, thermal decomposition of mono- and di-azocalixarene derivatives (A1–A8 and B1–B8) was investigated by means of thermogravimetry (TG), differential thermal analysis (DTA) and derivative thermogravimetry (DTG). The exclusion of methanol, hydrolysis of benzoyl ester and methyl ketone groups in lower rim, and decomposition of azo groups in upper rim have occurred during thermal analysis, consecutively. The thermal decomposition degrees amount of volatile pyrolysis products were determined in air atmosphere using TG, DTA and DTG curves. In conclusion, the thermal analyses of azocalixarenes demonstrated that its stability depends on the substituted groups and their positions in the calixarene structure.
New solid complex of nitrilotriacetic acid and bismuth trichloride was synthesized by a solid phase reaction of nitrilotriacetic
acid and bismuth trichloride at room temperature. The composition of the sample is BiCl3[N(CH2COOH)3]2.5. The crystal structure of the complex belongs to triclinic system with the lattice parameters: α=0.7849 nm, β=0.9821 nm,
χ=2.0021 nm, α=96.50, β=98.76 and γ=90.49. The far-infrared spectra show the bonding between the Bi ion and N atom of nitrilotriacetic
acid. The thermal analysis also demonstrates the complex formation between the bismuth ion and nitrilotriacetic acid. The
gaseous pyrolysis product and the final residue in the thermal decomposition process are determined to check the thermal decomposition
First casein was processed by pyrolysis and investigated under optimal thermal treatment condition to obtain a good quality
adsorbent with high developed porosity structure and liquid product as a complex raw material for different kind of organic
compounds with interesting properties and structures. The yields of hard residue, pitch, pyrolysis water and gases were determined
and compared with the yields of pyrolysis products of other investigated different kind of organic materials.
The chemical composition of pitch was determined as following: free carbons - 4.52%, organic acids - 0.64%, organic bases
-38.00%, phenols - 7.75%, asphaltenes - 0.97%, paraffin's - 1.30%, neutral oils - 16.20% and preasphaltanes - 30.10%. The
pitch was fractionated by air distillation into 3 liquid fractions with different boiling range and a bitumen like residue
with a lower softening temperature.
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.
When the organic matter or sulphide content of a mineral is above a given limit (e.g. in chalcogenides or shaly coal), its
burning under conventional conditions is not complete, sulphur and pyrolysis products being deposited on the colder parts
of the equipment.
In order to eliminate this error source, changes have been made in the construction of the equipment for simultaneous TG,
DTG, DTA and EGA (derivatograph). This part of the series describes the construction of the modified version of the apparatus,
its operating principle and the changes in the experimetal, conditions.