THE KINETICS OF THE THERMAL DECOMPOSITION OF VINYL ISOPROPYL ETHER

1953 ◽  
Vol 31 (4) ◽  
pp. 418-421 ◽  
Author(s):  
Arthur T. Blades

The thermal decomposition of vinyl isopropyl ether in the presence of toluene has been studied in a flow system in the temperature range 447–521 °C. In this range, the data indicate a purely intramolecular decomposition into propylene and acetaldehyde, the activation energy for the reaction being in close agreement with that found for the decomposition of vinyl ethyl ether. At 570 °C. a minor free radical decomposition of the ether becomes apparent. Some qualitative studies of the decomposition of vinyl isobutyl ether are also reported.

1940 ◽  
Vol 18b (11) ◽  
pp. 351-357 ◽  
Author(s):  
E. W. R. Steacie ◽  
Gerald Shane

An investigation has been made of the nitric oxide inhibited thermal decomposition of ethane. Apparent chain lengths of 2.4 to 5 are found at temperatures from 640° to 565 °C. The activation energy of the inhibited reaction is found to be 77.3 Kcal. The results are discussed and it is concluded that the thermal decomposition of ethane proceeds mainly by a rearrangement mechanism and that free-radical chain mechanisms for the ethane decomposition are untenable.


2013 ◽  
Vol 641-642 ◽  
pp. 144-147 ◽  
Author(s):  
Ming Hua Chen ◽  
Tao Zhang ◽  
Wen Ping Chang ◽  
Xiao Biao Jia

The thermal decomposition kinetics of RDX at different rates was studied by thermogravimetric analyzer(TG) and the activation energy of RDX was calculated by distributed activation energy model. It is shown that the thermal decomposition processes of RDX were divided into three stages according to the TG curves, they are molten stage, thermal decomposition stage and eng stage. The activation energies of RDX are all between 124.34 and 181.48KJ•mol-1 in the thermal decomposition stage of non-monotonously increasing. The activation energy of RDX is 139.98 KJ•mol-1 in the molten stage, and the thermal decomposition stage is167.24KJ•mol-1.


2019 ◽  
Vol 956 ◽  
pp. 181-191
Author(s):  
Jian Lin Xu ◽  
Bing Xue Ma ◽  
Cheng Hu Kang ◽  
Cheng Cheng Xu ◽  
Zhou Chen ◽  
...  

The thermal decomposition kinetics of polybutylene terephthalate (PBT) and flame-retardant PBT (FR-PBT) were investigated by thermogravimetric analysis at various heating rates. The kinetic parameters were determined by using Kissinger, Flynn-Wall-Ozawa and Friedman methods. The y (α) and z (α) master plots were used to identify the thermal decomposition model. The results show that the rate of residual carbon of FR-PBT is higher than that of PBT and the maximum mass loss rate of FR-PBT is lower than that of PBT. The values of activation energy of PBT (208.71 kJ/mol) and FR-PBT (244.78 kJ/mol) calculated by Kissinger method were higher than those of PBT (PBT: 195.54 kJ/mol) and FR-PBT (FR-PBT: 196.00 kJ/mol) calculated by Flynn-Wall-Ozawa method and those of PBT and FR-PBT (PBT: 199.10 kJ/mol, FR-PBT: 206.03 kJ/mol) calculated by Friedman methods. There is a common thing that the values of activation energy of FR-PBT are higher than that of PBT in different methods. The thermal decomposition reaction models of the PBT and FR-PBT can be described by Avarami-Erofeyev model (A1).


Nanomaterials ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 968 ◽  
Author(s):  
Abdenacer Benhammada ◽  
Djalal Trache ◽  
Mohamed Kesraoui ◽  
Salim Chelouche

In this study, carbon mesospheres (CMS) and iron oxide nanoparticles decorated on carbon mesospheres (Fe2O3-CMS) were effectively synthesized by a direct and simple hydrothermal approach. α-Fe2O3 nanoparticles have been successfully dispersed in situ on a CMS surface. The nanoparticles obtained have been characterized by employing different analytical techniques encompassing Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD) and scanning electron microscopy (SEM). The produced carbon mesospheres, mostly spherical in shape, exhibited an average size of 334.5 nm, whereas that of Fe2O3 supported on CMS is at around 80 nm. The catalytic effect of the nanocatalyst on the thermal behavior of cellulose nitrate (NC) was investigated by utilizing differential scanning calorimetry (DSC). The determination of kinetic parameters has been carried out using four isoconversional kinetic methods based on DSC data obtained at various heating rates. It is demonstrated that Fe2O3-CMS have a minor influence on the decomposition temperature of NC, while a noticeable diminution of the activation energy is acquired. In contrast, pure CMS have a slight stabilizing effect with an increase of apparent activation energy. Furthermore, the decomposition reaction mechanism of NC is affected by the introduction of the nano-catalyst. Lastly, we can infer that Fe2O3-CMS may be securely employed as an effective catalyst for the thermal decomposition of NC.


1940 ◽  
Vol 18b (1) ◽  
pp. 1-11 ◽  
Author(s):  
E. W. R. Steacie ◽  
H. O. Folkins

A detailed investigation of the inhibition by nitric oxide of the thermal decomposition of n-butane has been carried out over the temperature range 500° to 550 °C.In all cases it was found that inhibition decreased with increasing butane concentration. This suggests that radical recombination occurs in the normal decomposition by ternary collisions with butane molecules acting as third bodies.The activation energies of the normal and inhibited reactions have been determined. For high pressures the two values are in good agreement, viz., 58,200 and 57,200 cal. per mole respectively. The products of the inhibited reaction were also found to be the same as those of the normal reaction.It is concluded that free radical processes predominate, involving comparatively short chains.


Holzforschung ◽  
2017 ◽  
Vol 71 (3) ◽  
pp. 233-240 ◽  
Author(s):  
Ke-Chang Hung ◽  
Jyh-Horng Wu

Abstract Wood-SiO2 composites (WSiO2Cs) were prepared by means of the sol-gel process with methyltrimethoxysilane (MTMOS) as a reagent, and the physical properties, structure and thermal decomposition kinetics of the composites has been evaluated. The dimensional stability of the WSiO2Cs was better than that of unmodified wood, especially in terms of the weight percent gain (WPG), which achieved values up to 30%. The 29Si-NMR spectra show two different siloxane peaks (T2 and T3), which supports the theory about the formation of MTMOS network structures. Thermal decomposition experiments were also carried out in a TG analyzer under a nitrogen atmosphere. The apparent activation energy was determined according to the iso-conversional methods of Friedman, Flynn-Wall-Ozawa, modified Coats-Redfern, and Starink. The apparent activation energy between 10 and 70% conversion is 147–172, 170–291, 189–251, and 192–248 kJ mol−1 for wood and WSiO2Cs with WPGs of 10, 20, and 30%, respectively. However, the reaction order between 10 and 70% conversion calculated by the Avrami theory was 0.50–0.56, 0.35–0.45, 0.33–0.44, and 0.28–0.48. These results indicate that the dimensional and thermal stability of the wood could be effectively enhanced by MTMOS treatment.


1973 ◽  
Vol 51 (3) ◽  
pp. 366-369 ◽  
Author(s):  
P. N. Dastoor ◽  
E. U. Emovon

The kinetics of the thermal decomposition of ethyl, isopropyl, and t-butyl cyanides into HCN and the corresponding defines have been studied in a seasoned silica vessel in a flow system in the absence and presence of toluene as inhibitor. The reactions are homogeneous and the unimolecular rate constants are expressible by the following Arrhenius equations:[Formula: see text]


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Pakamon Pintana ◽  
Nakorn Tippayawong

Thermal behaviors and combustion kinetics of Thai lignite with different SO3-free CaO contents were investigated. Nonisothermal thermogravimetric method was carried out under oxygen environment at heating rates of 10, 30, and 50°C min−1from ambient up to 1300°C. Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS) methods were adopted to estimate the apparent activation energy (E) for the thermal decomposition of these coals. Different thermal degradation behaviors were observed in lignites with low (14%) and high (42%) CaO content. Activation energy of the lignite combustion was found to vary with the conversion fraction. In comparison with the KAS method, higherEvalues were obtained by the FWO method for all conversions considered. High CaO lignite was observed to have higher activation energy than the low CaO coal.


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