• Title, Summary, Keyword: Kissinger method

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Study on the Pyrolysis Kinetics of Mixture of RDF and Carbonized Sludge with Thermogravimetric Analysis (RDF와 탄화슬러지 혼합물의 열중량 및 열동역학 특성 연구)

  • Sun, Jian Feng;Hwang, Hyeon Uk;Kim, Myung Gyun;Nzioka, Antony Mutua;Lee, Chang Soo;Kim, Young Ju
    • Journal of Environmental Science International
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    • v.25 no.2
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    • pp.281-288
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    • 2016
  • After analyzing of heating value of four kinds of RDF, the RDF-D has the highest heating value, was chosen to be mixed with carbonized sludge by different ratio. The 85%:15% ratio, which has the highest efficiency, was analyzed with thermogravimetric and pyrolysis kinetics. Applying of Kissinger method, activation energy was obtained from slope which is calculated from relation of ln(${\beta}/T^2{_m}$) and $1/T_m$. The kinetic parameters obtained from Kissinger method were 46.06 kJ/mol of RDF, 55.99 kJ/mol of carbonized sludge and 40.68 kJ/mol of mixture of RDF and carbonized sludge. The mixture of RDF and carbonized sludge has the lowest activation energy and frequency factor, during thermal decomposition reaction it has the slowest reaction rate and needs the lowest energy. Although activation energy with pyrolysis of RDF was irregularly scattered, it showed that activation energy was stabilized by co-pyrolysis of RDF and additives(Carbonized Sludge).

Study on the Non-isothermal Crystallization Behavior of Polypropylene/Corn Starch-MB Blends (폴리프로필렌/옥수수전분 블렌드의 비등온결정화 거동 연구)

  • Kim, Youn-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.9 no.5
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    • pp.1125-1129
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    • 2008
  • Polypropylene (PP)/corn starch master batch(starch-MB) blends with different PP compositions of 90, 80, 70, and 60 wt% were prepared by melt compounding at $200^{\circ}C$, using lab scale Brabender mixer. The chemical structures, thermal properties and non-isothermal crystallization behavior of the PP/starch-MB blends were investigated by FT-infrared spectrometry (FT-IR), differential scanning calorimetry (DSC), and thermogravimetric analyzer (TGA). The fabrication of the PP/starch-MB blend was confirmed by the existence of hydroxy group in FT-IR spectrum. There was no district change in melting temperature and melting enthalpy, and TGA curve indicates a decrease in degradation temperature with starch-MB content. The non-isothermal crystallization process was analyzed using by Avrami equation. The Avrami exponents were in the range of 2.71-3.97 for PP and 1.48-1.99 for PP/starch-MB blonds. The activation energies calculated by Kissinger method were 233 kJ/mol for PP, 484 kJ/mol for PP90, 541 kJ/mol for PP80, 553 kJ/mol for PP70, and 422 kJ/mol for PP60.

Thermal Properties of Interpenetrating Polymer Network Epoxy-silicone Compound

  • Cho, Young-Shin;Shim, Mi-Ja;Klm, Sang-Wook
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.475-478
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    • 1999
  • The thermal properties of epoxy resin/siloxane for the electrical insulation were investigated by using dynamic DSC run method. As the heating rate increased, the peak temperature on dynamic DSC curve increased. From the linear relation on the Kissinger plot the curing reaction activation energy and pre-exponential factor could be obtained. The curing activation energy from the straight line of the Kissinger plot was 46.72 kJ/mol.

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Cure Kinetcs of DGEBA/MDA/GN/HQ System by DSC Analysis (DSC 분석에 의한 DGEBA/MDA/GN/HQ계의 경화반응 속도론)

  • Lee, J.Y.;Shim, M.J.;Kim, S.W.
    • Applied Chemistry for Engineering
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    • v.5 no.5
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    • pp.904-909
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    • 1994
  • Cure kinetics of DGEBA(diglycidyl ether of bisphenol A)/MDA(4,4'-methylene dianiline)/GN(glutaronitrile) system with and without HQ(hydroquinone) as a catalyst was studied by Kissinger equation and Fractional life method. The activation energy of the system with HQ was somewhat lower and the pre-exponential factor of that was higher by about 30% than those of the system without HQ. As 1.25phr of HQ was added, reaction rates increased about 1.8 times.

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Estimation of Activation Energy for the Free Radical Polymerization by Using Isoconversional Analysis (등전환 분석(Isoconversional Analysis)를 이용한 자유라디칼 중합의 활성화 에너지 계산)

  • Chung, I.
    • Elastomers and Composites
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    • v.39 no.4
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    • pp.281-285
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    • 2004
  • In this paper, the simple way to evaluate the value of the activation energy for the overall rate of free radical polymerization by using DSC thermograms was studied using free radical polymerization or butylacrylate as a model. Activation ehergies were determined at heating rates of 1, 2, 5, and $10^{\circ}C/min$ by applying the multiple scanning-rate methods of Kissinger, Osawa, and half-width methods as well as the single rate method of Barrett. The value of the overall activation energy measured was closely matched with the values calculated from individual data. This work also demonstrated that the use of the isoconversional method was a simple and effective way to estimate the activation energy for the overall free radical polymerization.

A Study on Formation and Thermal Decomposition Kinetics of PU Elastomers by Dynamic DSC and TGA Analysis (Dynamic DSC 및 TGA 열분석을 이용한 PU Elastomer의 중합반응 및 열분해 반응 Kinetics에 관한 연구)

  • Yoon, Soo-Koong;Ahn, Won-Sool
    • Elastomers and Composites
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    • v.42 no.1
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    • pp.47-54
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    • 2007
  • Reaction kinetics of polyurethane elastomers (PU) were studied using dynamic DSC and TGA for three PU samples of general purpose (Sample A), high temperature cross-likable CASE purpose with MOCA (Sample B), and RT cross-likable CASE purpose grade (Sample C). From DSC results, sample with MOCA(Sample B) showed lower shift of peak temperature, while showing broader thermograms than those of general purpose grade (Sample A). On the other hand, RT cross-linkable PU grade (Sample C) showed an interesting double mode reaction patterns, i.e., a lower temperature reaction at about $70\;^{\circ}C$, and a higher temperature reaction in the range of $140{\sim}170\;^{\circ}C$, indicating that it requires 2-step reaction process in order to complete the reaction. Once the cross-linking reaction completed, however, TGA results showed that all the samples would be considered to have similar chemical structures, showing similar decomposition processes. Sample C, especially, had showed decomposition properties of both Sample A and Sample B. Formation activation energies calculated from Kissinger method showed 10.39, 65.85, 36.52(Low $T_p$) and 18.21(High $T_p$) kcal/mol, while decomposition activation energies were 31.94, 30.84, 24.16 kcal/mol, respectively.

Cure Kinetics of Diglycidyl ether of bisphenol A-Methylene dianiline-Succlnonitrile System (Diglycidyl ether of bisphenol A/Methylene dianiline/Succinonitrile계의 경화반응 속도론)

  • Jo, Seong-U;Sim, Mi-Ja;Kim, Sang-Ok
    • Korean Journal of Materials Research
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    • v.2 no.4
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    • pp.257-262
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    • 1992
  • The cure kinetics of a diglycidyl ether of bisphenol A (DGEBA) with 4, 4'-methylene dianiline (MDA) added succinonitrile was studied through the dynamic run method by applying the data to the Kissinger equation which analyses the effect of the heating rate on the temperature at maximum reaction rate using Differential Scanning Calorimetry (DSC) analyzer in the range of 3$0^{\circ}C$-35$0^{\circ}C$. In the DGEBA/MDA system with SN, the activation energy ($E_a$) and the pre-exponential factor (A) were calculated. From these results, the rate constants (k) were obtained according to the different SN contents.

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Kinetic Studies of the Catalytic Low Rank Coal Gasification under CO2 Atmosphere (CO2분위기하에서 저급석탄 촉매가스화 반응 특성 연구)

  • Park, Chan Young;Park, Ji Yun;Lee, Si Hoon;Rhu, Ji Ho;Han, Moon Hee;Rhee, Young Woo
    • Korean Chemical Engineering Research
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    • v.50 no.6
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    • pp.1086-1092
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    • 2012
  • In this study, kinetic studies and analysis of the produced syngas were conducted for low rank coal gasification under $CO_2$ atmosphere. 6 coals were analyzed to measure amount of sulfur and ash by proximate and ultimate analyses. And then they were analyzed to select suitable sample by using Thermogravimetric analyzer (TGA). Selected coal sample Samhwa was mixed with catalysts. Mixed samples with catalysts were used to get activation energy under $CO_2$ atmosphere by using Kissinger's method and shrinking core model (SCM). Also, analysis of produced syngas was performed by Gas Chromatography (GC). In this experiment, activation of the $K_2CO_3$ was the best performance, and result of the analysis of the syngas showed similar trend with result of the activation energy.

Analyses of Nano Epoxy-Silica Degradation in LEO Space Environment (저궤도 우주환경에서 에폭시-실리카 나노 복합소재의 열화거동 분석)

  • Jang, Seo-Hyun;Han, Yusu;Hwang, Do Soon;Jung, Joo Won;Kim, Yeong Kook
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.48 no.12
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    • pp.945-952
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    • 2020
  • In this study, the effects of Low Earth Orbit(LEO) environments on the degradation behavior of epoxy nano silica composite materials were investigated. The nanocomposite materials containing silica particles in different weight ratios of 10% and 18% were prepared and degraded in a LEO simulator to compare with the neat epoxy cases. Thermogravimetric analysis (TGA) was performed on the degraded nanocomposites and the activation energies were calculated by Friedman method, Flynn-Wall-Ozawa (FWO) method, Kissinger method, and DAEM (Distributed Activation Energy Method) based on the iso-conversional method. As the results, for the neat epoxy sample cases, it was found that the average activation energy was increased as the degradation was progressed. When the nano particles were mixed, however, the energy increased to the 15 environmental test cycles, and decreased afterwards, meaning that the particle mixture contributed adversely to the thermal degradation. Discussions on the results of the different calculation methods were also given.

A Study on Effects of Vulcanization Systems on Cross-linking and Degradation Reactions of NR/CR Blends Using Dynamic DSC and TGA (Dynamic DSC와 TGA를 이용한 NR/CR 고무블렌드의 가황시스템이 가교 및 열화반응에 미치는 영향 연구)

  • Min, Byung-kwon;Park, DongRyul;Ahn, WonSool
    • Korean Chemical Engineering Research
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    • v.47 no.2
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    • pp.169-173
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    • 2009
  • Effects of variations sulfur/accelerator ratio on cross-linking and thermal degradation behavior of NR/CR rubber compounds were studied using both dynamic DSC and non-isothermal TGA. DSC thermograms of the given samples were obtained with several different heating rates, and after cross-liked in DSC, TGA thermograms with the same samples also obtained. Kissinger analysis was applied to assess the activation energies for the cross-linking and thermal decomposition processes. Results showed that the formation and thermal decomposition reaction of the samples occurred in the overall temperature range of $120{\sim}180^{\circ}C$ and $350{\sim}450^{\circ}C$, respectively, exhibiting that data could be well-fittable by Kissinger method. Furthermore, formation activation energy by DSC was estimated as $83.0{\pm}5.0kJ/mol$, which was much smaller than that of degradation by TGA, $147.0{\pm}2.0kJ/mol$. From these results, it was considered that, although variations of sulfur/accelerator ratio in the present experiments affected little on the formation mechanism and/or thermal degradation, they could play roles as the catalysts which lower the activation energy of formation. Because of stabilization after formation reaction, however, they have no more effects on the lowering the activation energy, showing higher values when decomposition, caused by main-chain scissions.