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1.
C. Tănase Lucia Odochian N. Apostolescu A. Pui 《Journal of Thermal Analysis and Calorimetry》2011,103(3):1079-1085
The article is devoted to the study on the thermal behaviour of three species of edible mushrooms: Boletus edulis (foot and cap), Pleurotus ostreatus (foot and cap), Lactarius deterrimus (cap) by the TG–FTIR-coupled technique, in air, over the 30–900 °C temperature range. The analysis of the TG–DTG–DTA curves
reveals the thermal degradation mechanism to be complex and specific to every species under the recording conditions applied.
A similar degradation mechanism is noticed for the foot and cap of Pleurotus ostreatus in comparison with the Boletus edulis and Lactarius deterrimus species where the mechanisms are different. The TG–FTIR analysis, combustion heats and IR spectra of the starting samples
also support these results. The initial degradation temperatures from TG–DTG indicate the temperature range where these species
are thermally stable and their nutrient features maintained making them proper for food. The TG–FTIR analysis gives information
on the gaseous species evolved by the thermal degradation bringing thus a contribution to the elucidation of the changes developing
by processing the edible mushrooms (industrialization, conservation, culinary preparations, etc.) at temperatures above the
initial degradation temperature. At the same time, the environmental impact, when the mushroom failed cultures are burned,
is also important. 相似文献
2.
Yu Huimei Qi Lingjun Zhang Qinghong Jiang Danyu Lu Changwei 《Journal of Thermal Analysis and Calorimetry》2011,106(1):47-52
The thermal behavior of the anticancer drug-irinotecan was measured by Thermogravimetry–Differential thermal analysis (TG–DTA)
to explore the application of TG–DTA in nanomedicine firstly. The TG–DTA result showed that the irinotecan was oxidized completely
before 700 °C. When irinotecan was loaded onto nanosized mesoporous silica spheres, the loading capacity for irinotecan measured
by TG–DTA was about 9.11% in the irinotecan/mesoporous SiO2 composite, similar to the typical UV–Vis spectra results (10.5%), which showed that TG–DTA characterization provided an alternative
method to determine the drug loading amount on inorganic carriers. Secondly, Thermogravimetry–Differential scanning calorimetry–Mass
Spectrometry coupling techniques (TG–DSC–MS) were used to characterize the hydrogen adsorption temperature and capacity of
TiCr1.2 (V-Fe)0.6 alloy. The MS result showed that the released region of hydrogen was 250–500 °C, which was consistent with the TG–DSC results.
Lastly, TA–MS combined with pulse thermal analysis (PulseTA) were used for a simultaneous characterizing study in the changes
of mass, determination and quantitative calibration of the evolved nitrogen formed during the thermal decomposition of the
InN powder. The results showed that relative error of this method between measured value and theoretical value was 2.67% for
the quantitative calibration of evolved N2. It shows that TA–MS combined with PulseTA techniques offer a good tool for the quantification of the evolved nitrogen in
the InN powder. 相似文献
3.
A free-base tetraphenyl porphyrin (TPP) and its corresponding metalloporphyrins (MTPP) where M = Co, Fe and Sn were synthesized
and characterized by UV–visible spectroscopy, FTIR and 1Hnmr spectroscopy. Thermal studies of these porphyrins were carried out in synthetic air from room temperature to 800 °C using
thermal analyser. The residues of MTPP after thermal treatment were qualitatively analysed, which showed the presence of corresponding
metal oxides. Further, the above MTPP were subjected to thermogravimetry–evolved gas and mass spectrometry (TG–EGA–MS) analysis
for the detailed information about evolved gases at their corresponding decomposition temperatures. This information may be
used to predict the probable mechanism for ring opening of the macromolecular porphyrins. 相似文献
4.
1,2,4-triazole-3-one (TO) and guanidine nitrate (GN) have the potential to be used as alternative gas-generating agents. To
obtain a better understanding of thermal decomposition properties of TO/GN mixtures, sealed cell differential scanning calorimetry,
thermogravimetry–differential thermal analysis–infrared spectroscopy (TG–DTA–IR), and thermogravimetry–differential thermal
analysis–mass spectrometry (TG–DTA–MS) were carried out. The endothermic peak and onset temperatures of TO/GN mixtures were
lower than those of individual TO and GN. TG–DTA–IR and TG–DTA–MS showed that the mass of TO/GN mixtures decreased with heat
generation and N2 evolved as the major gas during thermal decomposition. The interaction between TO and nitric acid from the dissociation of
GN is proposed for the thermal decomposition of TO/GN mixtures. 相似文献
5.
Thangamani Rajkumar Chinnaswamy Thangavel Vijayakumar Palanichamy Sivasamy Bojja Sreedhar Charles A. Wilkie 《Journal of Thermal Analysis and Calorimetry》2010,100(2):651-660
Imparting thermal stability to polymethyl methacrylate (PMMA) without affecting its optical clarity is attempted by incorporating
HET acid based oligoesters. Pure PMMA and PMMA containing five and 20 wt% of four different oligoesters are separately prepared
using bulk polymerization. The thermal properties of the materials studied using DSC, TG, TG–FTIR and Pyr–GC–MS are presented.
The main volatile degradation products identified are CO, HCl, CO2, H2O, hexachlorocyclopentadiene, hexachloroendomethylene tetrahydrophthalic acid/anhydride and methyl methacrylate. A detailed
mechanism for the influence of the degradation products of HET acid based oligoesters on the thermal degradation of PMMA is
also presented. 相似文献
6.
J. L. Perez-Rodriguez A. Duran L. A. Perez-Maqueda 《Journal of Thermal Analysis and Calorimetry》2011,104(2):467-474
In this study, the decomposition behaviour of unaltered and altered dolomitic rock samples used in Cultural Heritage buildings
was studied by simultaneous TG–DTA experiments at different atmospheres, X-ray diffraction in a high-temperature chamber,
and evolved gas analysis. The components of dolomite rock samples and hydrated calcium oxalate formed during the alteration
processes of the rocks were characterized, and the decomposition mechanisms of these components were determined. The TG–DTA
experiments carried out at CO2 atmosphere were used to determine the carbonate compounds in the rock samples. The TG–DTA study characterized the presence
of organic compounds formed during the biological degradation of the rock samples, possibly responsible of the hydrated calcium
oxalate formation. 相似文献
7.
Hou-yin Zhao Yan Cao Song P. Sit Quentin Lineberry Wei-ping Pan 《Journal of Thermal Analysis and Calorimetry》2012,107(2):541-547
The pyrolysis behavior of bitumen was investigated using a thermogravimetric analyzer–mass spectrometer system (TG–MS) and
a differential scanning calorimeter (DSC) as well as a pyrolysis-gas chromatograph/mass spectrometer system (Py-GC/MS). TG
results showed that there were three stages of weight loss during pyrolysis—less than 110, 110–380, and 380–600 °C. Using
distributed activation energy model, the average activation energy of the thermal decomposition of bitumen was calculated
at 79 kJ mol−1. The evolved gas from the pyrolysis showed that organic species, such as alkane and alkene fragments had a peak maximum temperature
of 130 and 480 °C, respectively. Benzene, toluene, and styrene released at 100 and 420 °C. Most of the inorganic compounds,
such as H2, H2S, COS, and SO2, released at about 380 °C while the CO2 had the maximum temperature peaks at 400 and 540 °C, respectively. FTIR spectra were taken of the residues of the different
stages, and the results showed that the C–H bond intensity decreased dramatically at 380 °C. Py-GC/MS confirmed the composition
of the evolved gas. The DSC revealed the endothermic nature of the bitumen pyrolysis. 相似文献
8.
C. Păcurariu R. I. Lazău I. Lazău D. Tiţa A. Dumitrel 《Journal of Thermal Analysis and Calorimetry》2011,103(2):435-441
Thermal and structural properties of three clays (sepiolite and two kaolinites) from Turkey were studied by thermal analysis
(TG–DTA), X-ray diffraction (XRD), X-ray fluorescence (XRF), Fourier transform infrared (FT-IR), and surface area measurement
techniques The adsorption of sulfur dioxide (SO2) gas by these clays was also investigated. SO2 adsorption values of K1, K2, and S clay samples were measured at 20 °C and pressures up to 106 kPa. Sepiolite sample (S)
primarily consists of pure sepiolite, only dolomite present as accompanying mineral. Both kaolinite samples, K1 and K2, mainly
contain kaolinite as the major clay mineral and quartz as impurity. In K2 sample, muscovite phase is also present. Simultaneous
TG–DTA curves of all clay samples were obtained at three different heating rates 10, 15, and 20 °C min−1 over the temperature range 30–1200 °C. It was found that the retention value of SO2 by S clay (2.744 mmol/g) was higher than those of K1 (0.144 mmol/g) and K2 (0.164 mmol/g) samples. 相似文献
9.
Commercial light-cured dental composites were used in this study. Two laboratorial composites, Resilab (Wilcos/Brazil), Epricord
(Kuraray/Japan) were compared under cured and uncured conditions. Thermal analysis, infrared spectroscopy and scanning electron
microscopy were used to evaluate the dental composites. The mass change and heat flow signals (TG–DSC) were recorded simultaneously
by using STA 409 PC Luxx (NETZSCH), in the 25–800 °C temperature range at a heating rate of 10 °C/min under nitrogen atmosphere
(70 mL/min). Employing thermo-microbalance TG 209 C F1 Iris (NETZSCH) coupled to the BRUKER Optics FTIR TENSOR, the samples
were analyzed by combined thermogravimetric and spectroscopic methods (TG–FTIR). The initial sample mass was about ~12 mg,
the data collection have been done in the 35–800 °C temperature range at a heating rate of 20 K/min in nitrogen atmosphere
(flow rate: 40 mL/min). Finally, superficial topographic was analyzed by scanning electron microscopy (SEM). Dental composite
evaluation suggests a high thermal stability and inorganic content in RES D sample. Degrees of conversion (DC) values were
almost the same and there was no direct relationship between DC and amount of particles and size. Similar compositions were
found in all samples. 相似文献
10.
Chun-Hong Jiang Li-Fang Song Cheng-Li Jiao Jian Zhang Li-Xian Sun Fen Xu Yong Du Zhong Cao 《Journal of Thermal Analysis and Calorimetry》2011,103(1):373-380
A three-dimensional lithium-based metal–organic framework Li2(2,6-NDC) (2,6-NDC = 2,6-naphthalene dicarboxylate) has been synthesized solvothermally and characterized by X-ray powder
diffraction, elemental analysis, FT-IR spectroscopy, thermogravimetry and mass spectrometer analysis (TG–MS). The framework
has exceptional stability and is stable to 863 K. The thermal decomposition characteristic of this compound was investigated
through the TG–MS from 293 to 1250 K. The molar heat capacity of the compound was measured by temperature modulated differential
scanning calorimetry (TMDSC) over the temperature range from 195 to 670 K for the first time. The thermodynamic parameters
such as entropy and enthalpy versus 298.15 K based on the above molar heat capacity were calculated. 相似文献
11.
Degradation of ethylenediaminetetraacetic acid (EDTA) present in the liquid waste was demonstrated by photocatalytic oxidation
route by using nanoparticles of anatase titania. Nano sized titania photocatalyst was synthesized using sol–gel method coupled
with ultrasonication mode and characterized using X-ray diffraction, transmission electron microscope, BET, Fourier transform
infrared spectroscopy and TG–DTA. A cylindrical photoreactor was employed for the degradation studies. Five milligram of the
nano anatase TiO2 + 0.5 ml of 30% H2O2 were employed as catalysts for the degradation studies of 1,000 mg/L EDTA. EDTA degradation was followed by a complexometric
titration method. Complete degradation of 1,000 mg/L EDTA could be achieved in 90 min and the photocatalytic efficiency of
the synthesized titania photocatalyst was higher than that of P-25 TiO2 for EDTA degradation. The influence of pH on the degradation of EDTA follow the order acidic > neutral > alkaline. More than
ten fold increases in the decontamination factors were obtained for the chemical precipitation step for the liquid waste containing
degraded EDTA compared to liquid waste without EDTA degradation. 相似文献
12.
Francesca Caterina Izzo Elisabetta Zendri Guido Biscontin Eleonora Balliana 《Journal of Thermal Analysis and Calorimetry》2011,104(2):541-546
Thermogravimetry coupled with differential scanning calorimetry (TG–DSC) has been commonly used in the field of conservation
of Cultural Heritage for the study of art objects, especially for the characterisation of inorganic matrixes. In recent years,
thermal analyses have been applied to the study of organic painting materials. The advantages of performing TG–DSC are linked
to the fact that it is micro-destructive technique which does not require any treatment prior the analysis and provide useful
information in relatively short time. The aim of this study is to describe the application of TG–DSC on the study of oil binders
used in contemporary paints. Even if synthetic binders have become increasingly popular in the 20th century, many contemporary
artists still prefer the more traditional media: drying oils. Although the wish of recalling traditional methods, much practical
knowledge in paint preparation by mixing drying oil and pigments and in the behaviour of the mixture has been lost. This is
mainly due to the different composition of contemporary materials in comparison with the traditional ones and may sometimes
lead to different drying properties of the oil paint formulations and consequent problems in the art creation and conservation.
For answer to this artistic need and in particular to the difficulties outlined by artists themselves in producing and employing
oil paints, unpigmented and pigmented oil films were studied after a week, 1 and 2 years of natural drying under laboratory
conditions. Thermal analyses were performed in air flow: the focus of this research was, in fact, to study the thermal and
oxidative behaviours of young films for better understanding the very first processes leading to the formation of the film. 相似文献
13.
E. Horváth J. Kristóf R. Kurdi É. Makó V. Khunová 《Journal of Thermal Analysis and Calorimetry》2011,105(1):53-59
Intercalation of a kaolinite-containing halloysite from Biela Hora (Slovakia) with urea was investigated by simultaneous TG–DTA,
XRD, FTIR (DRIFT), and Raman spectroscopy. The process of intercalation and thermal deintercalation was followed for the as-prepared
and the washed (with isopropanol) samples. The proposed structural model was supported by molecular mechanical calculations.
Incorporation of the intercalate (in 5 wt%) in molten polypropylene at 200 °C resulted in the complete delamination of the
mineral. It is supposed that gas formation as a result of urea decomposition between the layers prevents reorientation and
restructuring of the layers. 相似文献
14.
Luiz K. C. de Souza Juliana J. R. Pardauil José R. Zamian Geraldo N. da Rocha Filho Carlos E. F. da Costa 《Journal of Thermal Analysis and Calorimetry》2011,106(2):355-361
Al-modified MCM-41, La-modified MCM-41, and Ce-modified MCM-41 mesoporous materials were prepared with different molar ratios
(Si/M = 10; 25; 50; 100 and 200) at room temperature. The materials were characterized using XRD, BET–BJH, and TG–DTA. The
XRD showed four peaks, due to the ordered hexagonal array of parallel silica tubes, which could be indexed as (100), (110),
(200), and (210), assuming a hexagonal unit cell. The surface area decreased as the concentration of the metal incorporated
in the material increased. The thermal stability of the materials was around 650 °C. The CeO2 phase made the mass transfer process more difficult, hindering Hofmann degradation and favoring oxidation. 相似文献
15.
G. Madhurambal B. Ravindran M. Mariappan K. Ramamurthi S. C. Mojumdar 《Journal of Thermal Analysis and Calorimetry》2011,104(3):875-878
A single crystal of cinnamic acid–urea was grown by slow evaporation of methanol solution at room temperature. In this research,
many analytical methods such as FTIR, second harmonic generation, NMR, and TG–DTA were used. The presence of title compound
in the crystal lattice has been qualitatively determined by FTIR analysis. Thermal stability of the grown crystals was evaluated
by TG-DTA. Incorporation of urea increases the thermal stability insuring the suitability of material for possible non-linear
optical application up to 180 °C. 相似文献
16.
Chinnaswamy Thangavel Vijayakumar Nagarajan David Mathan Vijayakumar Sarasvathy Thangamani Rajkumar Arunachalam Thamaraichelvan Durairaj Ponraju 《Journal of Thermal Analysis and Calorimetry》2010,101(1):281-287
Intumescent materials, 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]-undecane-3,9-dioxide and 3,9-dichloro-2,4,8,10-tetraoxa-3,9-diphosphaspiro-[5,5]-undecane
having the capacity to produce dehydrating agent, blowing agent, and undergo carbonization during burning have been synthesized.
The thermal behavior of the synthesized materials was investigated using differential thermal analysis, thermal volatilization
analysis, programmed vacuum pyrolysis–mass spectrometry, flash pyrolysis–mass spectrometry and off-line pyrolysis–gas chromatography–mass
spectrometry. The materials show exothermic degradation after 250 °C. Monitoring the release of hydrogen chloride and water,
the blowing agents for the production of carbon foam, clearly indicated the superior performance of the pentavalent phosphorus
compound over the trivalent phosphorus compound. The major gaseous degradation products released during pyrolysis showed the
presence of sufficient quantities of several alkyl-substituted benzenes and fused aromatics. Suitable degradation mechanism
has been proposed and discussed to explain the formation of various organics during thermal degradation. 相似文献
17.
G. Vlase T. Vlase N. Doca M. Perţa G. Ilia N. Plesu 《Journal of Thermal Analysis and Calorimetry》2009,97(2):473-478
Samples of an organic–inorganic hybrid were prepared by solvolysis and polycondensation in formic acid of tetraethoxysilane
and diethylbenzyl phosphonate, simultaneous with the oxidative polymerization of aniline. The thermal behavior of the samples
in dynamic air atmosphere and non-isothermal conditions was determined by a coupled thermogravimetric/evolved gas analysis.
Two significant thermal events were established: the elimination from the polymeric matrix of low mass molecules, respectively
the thermooxidative degradation of the organic part of the matrix. The kinetic analysis was performed with the Flynn-Wall-Ozawa,
Friedman and modified Non-Parametric-Kinetic methods. Only the last one allowed an objective analysis of the first process
as a process of two simultaneous thermally induced phenomena with the kinetic functions of the type αm(1 − α)n. 相似文献
18.
Perret Birgit Pawlowski Kristin H. Schartel Bernhard 《Journal of Thermal Analysis and Calorimetry》2009,97(3):949-958
The pyrolysis of polycarbonate (PC) and PC/acrylonitrile-butadiene-styrene (PC/ABS) with and without arylphosphates (triphenylphosphate
TPP, resorcinol-bis(diphenyl phosphate) RDP and bisphenol A bis(diphenyl phosphate) BDP) is investigated by thermal analysis
as key to understanding the flame retardancy mechanisms and corresponding structure–property relationships. The correspondence
between the decomposition temperature range of arylphosphates and PC is pointed out as prerequisite for the occurrence of
the reaction between arylphosphate and structures that are typical for the beginning of PC decomposition. Resulting cross-linking
enhances charring in the condensed phase and competes with the alternative release of phosphate in the gas phase and thus
flame inhibition. Flame inhibition was identified as the main flame retardancy mechanism. The additional condensed phase mechanisms
optimise the performance. 相似文献
19.
B. Zapata J. Balmaseda E. Fregoso-Israel E. Torres-García 《Journal of Thermal Analysis and Calorimetry》2009,98(1):309-315
Thermal degradation of orange peel was studied in dynamic air atmosphere by means of simultaneous TG-DSC and TG-FTIR analysis.
According to the obtained thermal profiles, the orange peel degradation occurred in at least three steps associated with its
three main components (hemicellulose, cellulose and lignin). The volatiles compounds evolved out at 150–400 °C and the gas
products were mainly CO2, CO, and CH4. A mixture of acids, aldehydes or ketones C=O, alkanes C–C, ethers C–O–C and H2O was also detected. The E
α on α dependence reveled the existence of different and simultaneous processes suggesting that the combustion reaction is
controlled by oxygen accessibility, motivated by the high evolution low-molecular-mass gases and volatile organic compounds.
These results could explain the non-autocatalytic character of the reactions during the decomposition process. 相似文献
20.
The thermal oxidative degradation kinetics of pure acrylonitrile–butadiene–styrene (ABS) and the flame-retarded ABS materials
with intumescent flame retardant (IFR) were investigated using Kissinger, Flynn–Wall–Ozawa, and Horowitz–Metzger methods.
The results showed that the degradation of all samples included two stages, the activation energy at the first stage decreased
by the incorporation of these flame retardant components, while increased at the second stage. The activation energy order
of the flame-retarded ABS samples at stage 2 illustrates the relationship between the composition of IFRs and their flame
retardancy, FR materials with appropriate acid agent/char former ratio has higher activation energy and better flame retardancy. 相似文献