• Title, Summary, Keyword: Kissinger method

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Non-isothermal TGA Study on Thermal Degradation Kinetics of ACM Rubber Composites (비등온 TGA를 이용한 ACM 고무복합재료의 열분해 거동 연구)

  • Ahn, WonSool;Lee, Hyung Seok
    • Elastomers and Composites
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    • v.48 no.2
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    • pp.161-166
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    • 2013
  • Thermal degradation behavior of chlorine cure-site ACM and carboxylic cure-site ACM rubbers was studied by non-isothermal TGA thermal analysis. Carboxylic cure-site ACM rubber exhibited comparatively more thermally stable than chlorine cure-site ACM, showing higher peak temperature, at which maximum reaction rate occurred. Activation energies from Kissinger method were calculated as 118.6 kJ/mol for the chlorine cure-site ACM and 105.5 kJ/mol for the carboxylic cure-site ACM, showing similar values from Flynn-Wall-Ozawa analysis over the conversion range of 0.1~0.2. From the analysis of the reaction order change, both samples seemed thermally decomposed through the multiple reaction mechanism as is the common rubber materials.

A Study on Vulcanization Reaction of Modified Rubber Blends Using Dynamic Differential Scanning Calorimetry (Dynamic DSC를 이용한 개질 고무 블랜드의 가황 반응에 관한 연구)

  • Lee, Seung-Hyun;Ahn, Won-Sool
    • Elastomers and Composites
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    • v.38 no.4
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    • pp.326-333
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    • 2003
  • Even though many studies have been reported about rubber vulcanization, it is still remained difficult to find a quantitative relationship between the final states of vulcanized rubber and initial formulation or processing conditions. Dynamic differential scanning calorimetry (DSC) method is known as a comparatively easy method to research for the rubber vulcanization in both experimental and analysis. In the present research, a study on the vulcanization reaction of NR/CB composites modified by isoprene(IR) and chloroprene(CR) rubbers is carried out using dynamic DSC method. Thermograms with several different heating rates were obtained and analyzed using the Kissinger method. Analysis showed that the vulcanization reaction was progressed through the first order reaction mechanism. In addition, the reaction temperature was severely influenced by the kinds or rubber modifiers, in this case, more influenced by CR than by IR. Those effects were clearly verified in the values of activation energy. Kinds of carbon blacks, however, could hardly influence on the reaction mechanism.

Evaluation of Thermal Aging on PVC Using Thermo Gravimetry Analysis and Accelerated Thermal Aging Test (TGA와 가속열화를 이용한 전선 피복용 PVC의 열적 열화평가)

  • 박형주;김기환;김홍
    • Fire Science and Engineering
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    • v.18 no.3
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    • pp.45-50
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    • 2004
  • Thermal degradation of PVC which used for insulator of 600V vinyl insulated wire has been studied by thermo gravimetry analysis and accelerated thermal aging test. The activation energy using thermo gravimetry analysis was determined by the kinetic methods, such as Kissinger and Flynn-Wall-Ozawa. The activation energy was determined to from 89.29 kJ/mol to 111.39 kJ/mol in 600V PVC insulated wire and from 97.80 kJ/mol to 119.25 kJ/mol in 600v heat-resistant PVC insulated wire. And also, the activation energy through a long-term thermal aging test was calculated by using Arrhenius equation In the low temperature of 8$0^{\circ}C$, 9$0^{\circ}C$, 10$0^{\circ}C$. The results showed that 600V PVC insulated wire was 92.16 kJ/mol, and 600v heat-resistant PVC insulated wire was 97.52 kJ/mol. Consequently, the activation energy of 600V heat-resistant PVC insulated wire is larger than 600V PVC insulated wire. Therefore, it can be predicted that 600V heat-resistant PVC insulated wire has a long-term stability relatively.

Thermal Decomposition Activation Energy of Liquid Crystalline Epoxy Composite with Zirconia Filler (지르코니아를 함유한 열경화성 액정 에폭시의 열분해 활성화 에너지)

  • Moon, Hee Jung;Kim, Kyung Ho;Hwangbo, Sejin;Cho, Seung Hyun
    • Textile Science and Engineering
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    • v.52 no.3
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    • pp.206-214
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    • 2015
  • A liquid crystalline thermosetting epoxy 4,4'-diglycidyloxy-${\alpha}$-methylstilbene (DOMS) was synthesized using sulfanilamide as the curing agent. To heat cure the epoxy, filler contents of 0.5-5 wt% zirconia were used. Thermogravimetric analysis was performed, and the activation energy was calculated using the Kissinger and Flynn-Wall methods. The activation energy was proportional to the amount of zirconia used. As the activation energies needed for 1% and 10% decomposition were similar, the thermal decomposition was predicted to have the same mechanism.

Thermal Decomposition Behavior of LCT Composites with Modified Zirconia Filler (개질한 지르코니아를 함유한 열경화성 액정 에폭시의 열분해 거동)

  • Moon, Hee Jung;Cho, Seung Hyun
    • Textile Science and Engineering
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    • v.53 no.4
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    • pp.293-298
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    • 2016
  • In this study, liquid crystalline thermosetting epoxy resin (LCTER) was synthesized with 4,4'-diglycidyloxy-${\alpha}$-methylstilbene and sulfanilamide as a basic resin and curing agents, respectively. Following the synthesis, the LCTER composite was fabricated using modified zirconia as a filler. To investigate the thermal behavior of the LCTER composites, a thermogravimetric analysis of the LCTER composites was recorded on temperature difference, with a filler content of 0.5-5 wt% of modified zirconia. The activation energy for the thermal decomposition was calculated using the Kissinger and Flynn-Wall methods. It was found that the activation energies of LCTER composites were proportional to the amount of modified zirconia used in the composites.

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.