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1.
Thermogravimetric characteristics and kinetic of co-pyrolysis of olive residue with high density polyethylene 总被引:1,自引:1,他引:0
A. Aboulkas K. El Harfi M. Nadifiyine A. El Bouadili 《Journal of Thermal Analysis and Calorimetry》2008,91(3):737-743
The co-pyrolytic behaviour of olive residue/high-desity polyethylene mixture was examined with a thermogravimetric analyser.
The experiments were done over the temperature range of room temperature to 1273 K at various heating rates (2, 10, 20 and
50 K min−1) and in a nitrogen atmosphere.
The results indicated that mass loss process of mixture consists of three distinct stages and the increase of the heating
rate shifts in the maximum rate loss to higher temperature. The difference of mass loss (Δm) between experimental and theoretical, calculated as algebraic sums of the mixture for different heating rates of 2, 10,
20 and 50 K min−1, is about 7–11% at 740–900 K. These experimental results indicate a significant synergistic effect during co-pyrolysis of
olive residue with high-density polyethylene. In addition, a kinetic analysis was performed to fit thermogravimetric data,
the mixture is considered as multi-stage process. A reasonable fit to the experimental data was obtained for all materials
and their mixture by isoconversional Friedman method. 相似文献
2.
A. Aboulkas K. El Harfi A. El Bouadili M. Nadifiyine 《Journal of Thermal Analysis and Calorimetry》2010,100(1):323-330
Investigations into the pyrolytic behaviours of oil shale, poly (ethylene terephthalate) (PET) and their mixture have been
conducted using a thermogravimetric analyzer. Experiments were carried out dynamically by increasing the temperature from
298 to 1,273 K with heating rates of 2–100 K/min under a nitrogen atmosphere. Discrepancies between the experimental and calculated
TG/DTG profiles were considered as a measurement of the extent of interactions occurring on co-pyrolysis. The maximum degradation
temperature of each component in the mixture was higher than those the individual components; thus an increase in thermal
stability was expected. The kinetic processing of thermogravimetric data was carried out using Flynn–Wall–Ozawa (FWO) method. 相似文献
3.
This paper demonstrates the thermal pyrolysis of olive residue, low density polyethylene (LDPE) and olive residue/LDPE mixture in an inert atmosphere of N2 using thermogravimetric analysis (TGA). Measurements were carried out in the temperature range 300K~973K at heating rates of 2K/min, 10K/min, 20K/min and 50K/min. Based on the results obtained, three temperature regimes were selected for studying the nonisothermal kinetics of olive residue/LDPE mixture. The first two were dominated by the olive residue pyrolysis, while the third was linked to the LDPE pyrolysis, which occurred at much higher temperatures. Discrepancies between the experimental and calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on copyrolysis. The maximum degradation temperatures of each component in the mixture were higher than those the individual components; thus an increase in thermal stability was expected. The kinetic parameters associated with thermal degradation were determined using Friedman isoconversional method. 相似文献
4.
A. Aboulkas K. El Harfi A. El Bouadili M. Nadifiyine M. Benchanaa 《Journal of Thermal Analysis and Calorimetry》2009,96(3):883-890
Investigations into the pyrolytic behaviours of oil shale, poly (ethylene terephthalate) (PET) and their mixture have been
conducted using a thermogravimetric analyzer. Experiments were carried out dynamically by increasing the temperature from
298 to 1273 K with heating rates of 2 to 100 K/min under a nitrogen atmosphere. Discrepancies between the experimental and
calculated TG/DTG profiles were considered as a measurement of the extent of interactions occurring on co-pyrolysis. The maximum
degradation temperature of each component in the mixture was higher than those the individual components; thus an increase
in thermal stability was expected. The kinetic processing of thermogravimetric data was carried out using Flynn-Wall-Ozawa
(FWO) method. 相似文献
5.
A series of blends of poly(vinyl chloride) (PVC) and polyaniline (PANI) was prepared by solution casting and investigated
by methods of thermal analysis, namely thermogravimetric analysis (TG), coupled with Fourier transform infrared spectroscopy
(TG-FT/IR) and differential scanning calorimetry (DSC). It was found that the thermal stability of this polymer system depends
on the composition of blend; the main product of prevailing PVC decomposition process — hydrogen chloride — seems to play
specific role during degradation since it can react with PANI structures, characterized by different protonation degree.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
6.
A series of silicon containing poly(ester imide)s [PEIs] were synthesized using novel vinyl silane diester anhydride (VSEA)
and various aromatic and aliphatic dimines by two-step process includes ring-opening polyaddition reaction to form poly(amic
acid) and thermal cyclo-dehydration process to obtain poly(ester imide)s. VSEA was synthesized by using dichloro methylvinylsilane
and trimellitic anhydride in the presence of K2CO3 by nucleophilic substitution reaction. The PEIs were characterized by FTIR spectroscopy. The thermal properties of PEIs were
investigated by using differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) methods. The prepared PEIs
showed glass transition temperatures in the range of 320–350°C and their 5% mass loss was recorded in the temperature range
of 500–520°C in nitrogen atmosphere. These had char yield in the range of 45–55% at 800°C. 相似文献
7.
分别采用热重分析仪、真空固定床反应器和原子吸收光谱研究了污泥与醋糟共热解过程中反应动力学、产物分布和碱金属迁移行为,探究了协同效应及碱金属迁移规律。结果表明,两者共热解过程中存在明显协同效应;与理论计算相比,混合物分解所需的活化能下降了35.38%~29.49%,脱挥发指数比计算低3.5×10-8。协同效应导致气体产率增加,生物炭、液体产率降低;醋糟的存在加速了污泥的脱挥发分析出,提高了气体产物中合成气含量,加大了生物炭中大芳香环的裂解反应,使生物油中酚类和酯类物质含量明显增加;热解终止时,碱金属元素析出量达到79.19%~86.73%。 相似文献
8.
S. C. Mojumdar L. Raki N. Mathis K. Schimdt S. Lang 《Journal of Thermal Analysis and Calorimetry》2006,85(1):119-124
A non-ionic polymer (poly(vinyl
alcohol) (PVA)) has been incorporated into the inorganic layers of calcium
silicate hydrate (C–S–H) during precipitation of quasicrystalline
C–S–H from aqueous solution. C–S–H and a C–S–H-polymer
nanocomposite (C–S–HPN) material were synthesized and characterized
by X-ray fluorescence (XRF), energy dispersive spectroscopy (EDS), 29Si
magic angle spinning nuclear magnetic resonance (29Si
MAS NMR) and 13C cross-polarization nuclear magnetic
resonance (13C CP NMR) spectroscopy, atomic force
microscopy (AFM), thermal conductivity, thermogravimetric analysis (TG) and
differential thermal analysis (DTA). Thermal conductivity of PVA, C–S–H
and C–S–HPN material was studied in the temperature range 25–50°C.
C–S–HPN materials exhibited the highest thermal conductivity at
25 and 50°C. The thermal conductivity increases from 25 to 50°C are
7.03, 17.46 and 14.85% for PVA, C–S–H and C–S–HPN
material, respectively. Three significant decomposition temperature ranges
were observed on the TG curve of C–S–HPN material. 相似文献
9.
Mouaïne K. Becker P. Carabatos-Nédelec C. 《Journal of Thermal Analysis and Calorimetry》1999,55(3):807-816
Differential scanning calorimetry (DSC) and thermogravimetric analysis (TG) of lithium formate monohydrate (LiHCOO·H2O) were performed in the temperature range 300–700 K. The DSC/TG measurements show that the dehydration process to anhydrous
lithium formate (LiHCOO) is complex and occurs in two stages. The data are correlated to the structure and to the arrangement
of the molecules in the crystal, including the hydrogen-bonding. Infrared transmittance and Raman spectra of this crystal
are reported and commented on.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
10.
A series of calcium silicate hydrate (C–S–H)-polymer nanocomposite
(C–S–HPN) materials were prepared by incorporating poly(acrylic
acid) (PAA) into the inorganic layers of C–S–H during precipitation
of quasicrystalline C–S–H from aqueous solution. The as-synthesized
C–S–HPN materials were characterized by X-ray fluorescence (XRF),
X-ray diffraction (XRD), scanning electron microscopy-energy dispersive spectroscopy
(SEM-EDS), Fourier-transform infrared (FTIR) spectroscopy, thermogravimetric
analysis (TG) and differential scanning calorimetry (DSC). The XRD analysis
of C–S–HPN materials suggest the intermediate organizations presenting
intercalation of PAA within C–S–H and exfoliation of C–S–H.
The SEM micrographs of C–S–H, PAA and C–S–HPN materials
with different PAA contents exhibit the significant differences in their morphologies.
The effect of the material’s composition on the thermal stability of
a series of C–S–HPN materials along with PAA and C–S–H
were studied by TG, DTA and DSC. Three significant decomposition temperature
ranges were observed on the TG curves of all C–S–HPN materials. 相似文献
11.
Polymer composite materials were prepared from poly(ethylene terephthalate)–poly(trimethylene terephthalate) blends as the
matrix and different microcrystalline cellulose (MCC) filler levels (0–40 wt%) using melt compounding followed by compression
molding. The composites were analyzed using dynamic mechanical thermal analysis (DMTA), differential scanning calorimetry
(DSC) and thermogravimetric analysis (TG). The DSC results indicated that there is no consistent or significant influence
of the MCC addition on the glass transition (T
g), melting (T
m), and crystallization temperature of the composites. With increasing MCC content, dynamic mechanical properties improved
because of the reinforcing effect of the MCC. The tan δ peak values from the DMTA were not significantly changed as the MCC
content increased. TG indicated that the onset temperature of rapid thermal degradation decreased with increasing MCC content.
It was also found that the thermal stability of the composites slightly decreased as the MCC content increased. 相似文献
12.
Ch. V. Subba Reddy Edwin H. Walker Jr. S. A. Wicker Sr. Quinton L. Williams Rajamohan R. Kalluru 《Journal of Solid State Electrochemistry》2009,13(12):1945-1949
We synthesized MoO3 nanorods using poly (vinyl pyrrolidone) (PVP) as a surfactant through the hydrothermal route for making a cathode for a lithium
battery. Scanning electron microscopy images reveal the structures to have dimensions on the order of 1–10 μm in length and
50–200 nm in diameter. Analytical techniques such as X-ray diffractometry, Fourier transformation infrared spectroscopy, thermogravimetric
analysis, and cyclic voltammetry were used to characterize the nanorods. The measured specific charge of MoO3 nanorods prepared through a 15-day hydrothermal reaction was 156 mAhg−1 during the initial discharge process. 相似文献
13.
E. Kowalska J. Radomska P. Konarski R. Diduszko J. Oszczudłowski T. Opalińska M. Więch Z. Duszyc 《Journal of Thermal Analysis and Calorimetry》2006,86(1):137-140
Two components
of electronic wastes (sample A – a mixture of three types of printed
circuit boards, sample B – a mixture of electronic junctions with metal
wires) were investigated using thermogravimetric analysis (TG). Thermogravimetric
and derivative thermogravimetric data (TG and DTG) give information on the
thermal stability of A and B samples and allows finding the correct conditions
for their degradation using pyrolysis in an experimental system, built on
the laboratory scale for utilization of hazardous wastes. X-ray fluorescence
measurements prove that brominated flame retardant is present in sample A,
whilst chlorinated flame retardant is a probable component of sample B. Preliminary
liquid chromatography of oil products obtained as a result of thermal waste
degradation shows that the hydrocarbons released during pyrolysis could be
used as a fuel. 相似文献
14.
W. S. Drumond C. G. Mothé S. H. Wang 《Journal of Thermal Analysis and Calorimetry》2006,85(1):173-177
The thermogravimetric analysis (TG) of two series
of tri-block copolymers based on poly(L,L-lactide) (PLLA) and poly(ethyleneglycol) (PEG)
segments, having molar mass of 4000 or 600 g mol–1,
respectively, is reported. The prepared block copolymers presented wide range
of molecular masses (800 to 47500 g mol–1)
and compositions (16 to 80 mass% PEG). The thermal stability increased with
the PLLA and/or PEG segment size and the tri-block copolymers prepared from
PEG 4000 started to decompose at higher temperatures compared to those copolymers
from PEG 600. The copolymers compositions were determined by thermogravimetric
analysis and the results were compared to other traditional quantitative spectroscopic
methods, hydrogen nuclear magnetic resonance spectrometry (1HNMR)
and Fourier transform infrared spectrometry (FTIR). The PEG 4000 copolymer
compositions calculated by TG and by 1HNMR, presented
differences of 1%, demonstrating feasibility of using thermogravimetric analysis
for quantitative purposes. 相似文献
15.
P. Budrugeac 《Journal of Thermal Analysis and Calorimetry》2008,92(1):291-296
The thermo-oxidative degradation of poly(vinyl alcohol) (PVA) has been investigated by TG+DTG+DTA simultaneous analysis performed
in static air atmosphere, at four heating rates, namely 3, 5, 10 and 15 K min−1. TG, DTG and DTA curves showed that, in the temperature range 25–700°C, four successive processes occur. The first process
consisting in the loss of physical adsorbed water is followed by three processes of thermal and/or thermo-oxidative degradations.
The processing of the non-isothermal data corresponding to the second process (the first process of thermo-oxidation) was
performed by using Netzsch Thermokinetics — A Software Module for Kinetic Analysis.
The dependence of the activation energy evaluated by Friedman’s isoconversional method on the conversion degree shows that
the investigated process is complex one. The mechanism of this process and the corresponding kinetic parameters were determined
by Multivariate Non-linear Regression Program and checked for quasi-isothermal experimental data. It was pointed out that
the first process of thermo-oxidation of PVA consists in three consecutive steps having Avrami-Erofeev kinetic model. The
obtained results can be used for prediction of the thermal lifetime of PVA corresponding to a certain temperature of use and
an endpoint criterion. 相似文献
16.
D. V. Vlasov L. A. Apresyan T. V. Vlasova V. I. Kryshtob 《Polymer Science Series A》2011,53(5):430-436
The anomalous behavior of the electrical conductivity of transparent poly(vinyl chloride) films is experimentally studied
at field voltages approaching the breakdown threshold, above the threshold, and far below the threshold. The effects of strong
nonlinearity, relaxation drifts, and spontaneous reversible transitions between states with high and low electrical conductivities
are revealed for the first time in “thick” (20–100 μm) plasticized transparent poly(vinyl chloride) films. When a certain
threshold is exceeded, relaxation oscillations in the test sample are generated and their frequency is proportional to the
applied voltage. During a “mild” breakdown, the polymer film passes into the high-conductivity state (the current increases
by four or more orders of magnitude), which is identical to the states observed during low-voltage transitions. A simple qualitative
model explaining the anomalous character of the electrical conductivity of plasticized poly(vinyl chloride) films is advanced. 相似文献
17.
Rafael Marangoni José Eduardo Ferreira da Costa Gardolinski Alexandre Mikowski Fernando Wypych 《Journal of Solid State Electrochemistry》2011,15(2):303-311
Zn2Al-layered double hydroxides (LDH) were intercalated with anions of the dyes Orange G, Orange II, and Methyl Orange by alkaline
co-precipitation of aqueous solutions of zinc chloride and aluminum nitrate simultaneously in the presence of dye sodium salts.
Transparent, homogeneous, and colored nanocomposite films were obtained by casting after dispersing the dye-intercalated LDHs
(pigments) into commercial poly(vinyl alcohol) (PVA). The films were characterized by X-ray diffraction, ultraviolet–visible
spectroscopy, thermal analysis (thermogravimetric analysis (TGA)) and differential thermal analysis (DTA)), and mechanical
testing. Mechanical reinforcement of the PVA compounded with the dye-intercalated LDHs was achieved, and reasonable increases
in Young’s modulus and ultimate tensile strength were observed with as little as 0.5% added filler, while larger amounts tended
to decrease the reinforcement effect. These results demonstrate the onset of a new range of potential applications for layered
double hydroxide intercalated with dyes in the preparation of polymer composite multifunctional materials. 相似文献
18.
Hybrid materials from poly(vinyl chloride) (PVC) and silica have been prepared using different conditions by the sol–gel technique.
In situ generation of silica network in the PVC matrix was carried out by hydrolysis/condensation of tetraethoxysilane (TEOS)
in the matrix. Morphology of the silica particles produced in hybrid films was studied by scattering electron microscopy.
The shape of silica particle produced in the matrix was modified by carrying out the sol–gel process under steam on the hybrid
films using TEOS. The films were subjected to strain conditions during this process, which produced lamellar shaped particles
in the matrix. It was possible to produce platelet type of structure with different aspect ratio by changing the composition
and the stress conditions on the films during the steaming process. Addition of a very small amount of γ-glycidoxypropyltrimethoxysilane
as compatibilizer drastically reduced the silica particles size in the matrix to nano-level. Thermal–mechanical properties
of some of these hybrids were studied and related to the composition, structure and inter-phase interaction between the silica
and the matrix. 相似文献
19.
A. Aboulkas K. El Harfi A. El Bouadili M. Ben Chanâa A. Mokhlisse 《Journal of Thermal Analysis and Calorimetry》2007,89(1):203-209
The pyrolysis of oil shale and plastic wastes is being presently considered as an alternative means of partial substitution
of fossil fuels to generate the necessary energy to supply the increasing energy demand and as well as new technology to reduce
the negative environment of plastic wastes. However, Knowledge of pyrolysis kinetics is of great imponrtance for the design
and simulation of the reactor and in order to establish the optimum process conditions.
In this study, the thermal decomposition of polypropylene, oil shale and their mixture was studied by TG under a nitrogen
atmosphere. Experiments were carried out for various heating rates (2, 10, 20, 50 K min−1) in the temperature range 300–1273 K. The values of the obtained activation energies are 207 kJ mol−1 for polyethylene, 57 kJ mol−1 for the organic matter contained in the oil shale and 174 kJ mol−1 for the mixture. The results indicate that the decomposition of these materials depends on the heating rate, and that polypropylene
acts as catalyst in the degradation of the oil shale in the mixture. 相似文献
20.
Hengfeng Li Kaiyuan Tan Zeming Hao Guowen He 《Journal of Thermal Analysis and Calorimetry》2011,105(1):357-364
A number of solution-casted poly(vinylidenefluoride–chlorotrifluoroethylene–trifluoroethylene) [P(VDF–CTFE–TrFE)] terpolymer
films with different CTFE content have been characterized by a series of thermal analysis techniques, including thermogravimetric
analysis (TG), differential scanning calorimetry, dynamic mechanical analysis (DMA) and thermal mechanical analysis (TMA).
The work intends to provide more comprehensive information about thermal behavior of these ferroelectric polymers. TG results
suggest that the introduction of the CTFE units slightly decreases the thermal stability of the polymer due to the instability
of C–Cl bond during heating. DMA detected a relatively weak αa relaxation and a broad αc relaxation in the samples of low CTFE content. These two relaxation processes completely mixed together in the sample with
high CTFE content, revealing the crystalline structures in the polymer, become a more imperfect and diffuse state as CTFE
units increasing. The polymer with less CTFE units possesses an enhanced stiffness due to its higher degree of crystallinity.
A contraction process after a slight amount of thermal expansion upon heating is detected by TMA, due to the release of internal
tensile strain/stress generated during solidification of the films. The higher crystallinity of the polymer film generated
the greater strain/stress, leading to the larger degree of shrinkage. Also, the higher melting point of the polymer with less
CTFE units allows the film soften at a higher temperature. 相似文献