Authors:M. I. Loría-Bastarrachea, W. Herrera-Kao, J. V. Cauich-Rodríguez, J. M. Cervantes-Uc, H. Vázquez-Torres, and A. Ávila-Ortega
fundamental knowledge on the thermal degradation pathways of poly( N -vinyl pyrrolidone) using Thermogravimetry coupled with Fourier Transform Infrared Spectroscopy (TG–FTIR) to analyze the evolved gases during decomposition. In addition, the partially
stability and thermal degradation of aramid fibers, but there are few publications on the comparison in their thermal stability and analysis of thermal degradation process by TG/FTIR and Py-GC/MS.
In this article, the thermal degradation of Kevlar 49
Authors:A. Marcilla, M. I. Beltrán, and R. Navarro
The effect of regeneration conditions on the composition of the gases evolved during the catalytic pyrolysis of low density (LDPE) and high density polyethylene (HDPE) with HUSY and HZSM5 catalysts has been analysed by the TG/FTIR technique. When regenerated HUSY was employed, the evolution of the gases obtained was similar to that with fresh HUSY, indicating that the regeneration treatment did not affect its properties. Nevertheless with HZSM5, as the regeneration temperature was higher, the composition of the gases gradually became more similar to that evolved in the thermal process.
Authors:C. Tănase, Lucia Odochian, N. Apostolescu, and A. Pui
(conservation, culinary preparations, etc.) and since the failed cultures might be capitalized by burning, this study is completely justified.
By taking into account the fact that the coupled TG–FTIR analysis has lately been proved to be very efficient
products of pyrolysis. Thermogravimetric analyser coupled with Fourier transform infrared spectrometer (TG-FTIR) is a useful tool in dynamic analysis as it monitors continuously both the weight of the non-volatile materials (residue) and the time
Authors:S. Hirose, T. Hatakeyama, Y. Izuta, and H. Hatakeyama
Thermal degradation behaviour of alcoholysis lignin-based polycaprolactones (ALPCL's) with various molar ratios of β-caprolactone
monomer to each hydroxyl group of lignin (CL/OH ratios) was studied by TG-FTIR. The temperature was varied from 20 to 800C.
Thermal degradation temperatures (Td's) of alcoholysis lignin (AL) and ALPCL's were determined using TG curves. Td increased with increasing CL/OH ratio, suggesting that AL becomes thermally stable after the derivatization with PCL chains.
Mass residue (MR) at 500C was also determined using TG curves. MR values decreased with increasing CL/OH ratios. The evolved
gases formed by thermal degradation of ALPCL's at various temperatures were simultaneously analyzed by FTIR. The main peaks
observed for the samples are as follows: wavenumber (assignment): 1160 cm-1 (vC-O-), 1260 cm-1(-C(=O)-O-C-), 1517 and 1617 cm-1 (vC=C), 1770 cm-1 (vC=O), 2345 cm-1 (vCO2), 2945 cm-1 (vC-H) and 3700 cm-1 (vOH). It was found that the peak intensities for C=O, CH, C-O-C, OH peaks, which were observed for evolved gases at 430C,
increased with increasing CL/OH ratios, suggesting that the evolved gases at 430C are mainly formed by thermal degradation
of PCL chains in ALPCL's.
Authors:R. Kunze, B. Schartel, M. Bartholmai, D. Neubert, and R. Schriever
Thermogravimetry (TG), thermogravimetry coupled with mass spectroscopy (TG-MS) and thermogravimetry coupled with Fourier transform
infrared spectroscopy (TG-FTIR) were used to characterise the thermo-oxidative behaviour of two intumescent coating materials.
The temperature dependence, the corresponding volatile products and the amount of residue of the different processes were
determined. Using both TG-MS and TG-FTIR results in an unambiguous interpretation of the volatile products. Characteristics
such as the influence of endothermic reactions, the release of non-flammable gases, the dehydrogenation enhancing the char
formation and the stability of the cellular char were discussed in detail. It was demonstrated, that TG, TG-MS and TG-FTIR
are powerful methods to investigate mechanisms in intumescent coatings and that they are suitable methods in respect to quality
assurance and unambiguous identification of such materials.
Authors:Anca Mocanu, Lucia Odochian, N. Apostolescu, and C. Moldoveanu
The study on the thermal behavior of some new diazoaminoderivatives was aimed to follow the structure-thermal stability-degradation
mechanism correlation by means of the TG-FTIR technique and formation enthalpies. The TG-DTG-DTA curves reveal the thermal
degradation in air (30–900 °C) to show two ranges as a function of temperature (time), where the gaseous species resulting
by degradation are eliminated: the first, an endothermic one which is identical to that under nitrogen atmosphere and the
second, an exothermal one. As made evident by the identification of the individual gaseous species by their characteristic
absorbances as well as those obtained by TG-FTIR the compounds C2H2, H2C = NH, SO2, NH3, CO2, H2O, HCl are eliminated in the first domain while CO2, SO2, H2O in the second, which afforded the advancement of the most probable degradation mechanism.
Authors:Bruno Souza, Ana Moreira, and Ana Teixeira
Thermogravimetry has been widely used for the characterization of several biomasses but the most useful information given
by this technique has been normally concerned to the relative amounts of humidity, hemi-cellulose, cellulose and lignin present
in the biomass. TG-FTIR has been used to yield qualitative data about the pyrolysis products, in an exploratory way, by some
authors. In the present paper, this technique was employed to reach comparative data about the products of pyrolysis of biomasses
that are potentially available at economic bases for the production of biofuels. Agricultural residues such as coconut shell,
sugarcane bagasse, corn stalks and peanut shell were chosen to be investigated. For all samples, the thermogravimetric curves
showed a mass loss between 35 and 400 °C changed up to 73%, while that the loss between 400 and 800 °C changed up to 26%.
TG-FTIR indicated tendencies in the rate of the formation of important species during the pyrolysis process of the four biomasses
studied. The interpretation of the spectra allowed the proposition of characteristic absorbance ratios and the comparison
of these values allowed inferences about the relative abundances of components formed in the pyrolysis of the biomasses. As
an example of the possible inferences reached, among the species formed in the pyrolysis condensate, called bio-oil, the formation
of carboxylic acids has to be specially considered due to their corrosivity. Thus, the data produced indicated that a bio-oil
derived from peanut shell should be a little less acidic while the one derived from sugarcane bagasse should be showed more
acidic among the biomasses studied.
The thermal decomposition of sodium ethyl xanthate (SEX) was used to compare the techniques of pyrolysis-gas chromatography-mass
spectrometry (py-GC-MS), thermogravimetry-Fourier transform infrared spectroscopy (TG-FTIR), and TG-MS.
In the py-GC-MS analysis, SEX was pyrolysed at 400C in an inert atmosphere. Major gases evolved were carbon disulfide, diethyl
sulfide, ethanol, and carbonyl sulfide. The TG of SEX exhibited a sharp mass loss at 201C (42.3%) and a gradual mass loss
at 217-325C (20.8 %). The MS spectra of the evolved gases were complex due to overlapping of molecular, isotope, and fragment
ion signals. Using the MS in selected ion monitoring mode, the major gases evolved were found to be carbon disulfide and carbonyl
sulfide. The FTIR spectra of the evolved gases displayed vibrational frequencies due to alkanes, carbonyls, carbonyl sulfide,
and carbon disulfide.
From the analyses it was concluded that py-GC-MS provided unambiguous gas identification. Interpretation of the MS results
was reliant on the py-GC-MS results, and the FTIR data was limited to identifying gases with very characteristic vibration