• 폴리머
• /
• 제37권2호
• /
• pp.240-248
• /
• 2013

본 연구에서는 DGEBA(diglycidyl ether of bisphenol A)를 사용한 에폭시/mercaptan 경화제의 경화 반응 거동을 에폭시/아민 유도체형 경화제와 비교하여 연구하였다. 경화 반응 거동은 DSC 분석에 의해 승온 및 등온의 조건에서 경화되는 과정을 연구하였다. DSC의 승온 실험에서는 Kissinger 법을 이용하였으며, 등온 실험에서는 Kamal의 속도모델을 이용하여 분석하였다. 결과적으로 활성화 에너지는 아민 유도체형 경화제를 사용하였을 때 약 40 kcal/mol이고, mercaptan 경화제를 사용하였을 때 약 28에서 19 kcal/mol로 -SH 관능기가 증가할수록 감소하였다. 에폭시/아민 유도체형 경화제는 약 $90^{\circ}C$ 이상에서 경화 반응이 개시되는 반면, 에폭시/mercaptan 경화제에서는 경화 반응 개시 온도가 약 $80^{\circ}C$ 이내로 낮아지고, 반응 속도가 상승하여 반응 시간이 10분 이내로 단축되었다. 또한 에폭시/mercaptan 경화제계는 자기 촉매 반응 모델을 따르는 것을 확인하였고 약 20~40%의 경화도에서 최대 반응속도를 나타내었다.

• 한국복합재료학회:학술대회논문집
• /
• 한국복합재료학회 2001년도 춘계학술발표대회 논문집
• /
• pp.118-121
• /
• 2001

The investigation of cure kinetics and morphology studies on DGEBA/PEI/Anhydride system were performed by differential scanning calorimetry and scanning electron microscopy. Autocatalystic kinetics model was applied by isothermal scan test. Ozawa method and Kissinger method was applied by temperature scan. Activation energy was 95kJ/mol for neat DGEBA/NMA, 120kJ/mol for DGEBA/PEI(10p.h.r.)/NMA. The generation of secondary phase of PEI was observed and its size was grown up by increasing contents of PEI.

• 한국재료학회지
• /
• 제13권11호
• /
• pp.721-724
• /
• 2003

A Fe-Si-B-Ni amorphous alloy manufactured by one roll melt-spinning method showed the crystallization temperature difference of a maximum $10^{\circ}C$ according to each lot. This temperature difference had a considerable influence on the annealing process to be conducted for obtaining the proper inductance of the alloy. The proper annealing temperature of the alloy was $480^{\circ}C$ and the annealing time increased as the crystallization temperature increased. The activation energy measured by Kissinger method increased as the crystallization temperature increased. Therefore, the annealing process must be adjusted by the crystallization temperature difference of the amorphous alloy.

• 자원리싸이클링
• /
• 제24권5호
• /
• pp.15-21
• /
• 2015

폐플라스틱은 조성뿐만 아니라 다양한 플라스틱의 종류로 인하여 열분해 및 연소 속도가 달라진다. 본 연구는 폐플라스틱 고체 연료 (Refused Plastic Fuel)의 열분해 및 연소 시 설계요소 도출을 위한 열중량 분석 및 동역학 특성을 규명하였다. 열중량 분석기 (Thermogravimetric analysis)의 결과을 이용하여 동력학 특성 중 가장 일반적인 방법인 Kissinger 방법을 통하여 활성화 에너지를 구하였다. TGA의 실험 조건은 다음과 같이 설정하였다. 질소 가스유량 20 ml/min, 승온 속도 $5{\sim}50^{\circ}C/min$ 및 최대온도는 $800^{\circ}C$로 하였다. 본 연구의 폐플라스틱 열분해 특성 연구를 위하여 적용된 방법은 실제의 반응기에서 반응기의 성능, 설계 및 최적 운전조건을 결정할 때 기초자료로 사용될 수 있을 것으로 사료된다.

• 한국분말재료학회지
• /
• 제16권3호
• /
• pp.191-195
• /
• 2009

The calcination and hydrogen-reduction behavior of Fe- and Ni-nitrate have been investigated. $Fe_2O_3$/NiO composite powders were prepared by chemical solution mixing of Fe- and Ni-nitrate and calcination at $350^{\circ}C$ for 2 h. The calcined powders were hydrogen-reduced at $350^{\circ}C$ for 30 min. The calcination and hydrogen-reduction behavior of Fe- and Ni-nitrate were analyzed by TG in air and hydrogen atmosphere, respectively. TG and XRD analysis for hydrogen-reduced powders revealed that the $Fe_2O_3$/NiO phase transformed to $FeNi_3$ phase at the temperature of $350^{\circ}$. The activation energy for the hydrogen reduction, evaluated by Kissinger method, was measured as 83.0 kJ/mol.

• 한국세라믹학회지
• /
• 제29권1호
• /
• pp.9-14
• /
• 1992

Some of non-isothermal analysis methods are applied to CaO-MgO-Al2O3-SiO2 glass system to find the kinetics parameters of crystallisation, activation energy, Avrami component and frequency factor. The results using the non-isothermal analysis were compared to that of microstructure experiment. Analysis of the result has enabled to some methods to be to recommend as being the most appropriate equation to use in a glass system. It was shown that in the thermal analysis using the non-isothermal method of Kissinger, Augis-Bennett, Bansal, and Marotta, the calculation of activation energy is not much different, while Avrami component and frequency factor are different from applied each methods.

• 열처리공학회지
• /
• 제24권4호
• /
• pp.193-198
• /
• 2011

Effect of CaO addition on age hardening response has been studied by using optical microscopy, scanning electron microscopy and differential thermal analysis in AZ91 and CaO-containing ECO-AZ91 alloys. After solution treatment, the ${\beta}$($Mg_{17}Al_{12}$) phase formed during solidification mostly disappeared in the microstructure in the AZ91 alloy, whereas numerous ${\beta}$ precipitates containing Ca were still observed in the ECO-AZ91 alloy due to its enhanced thermal stability. The ECO-AZ91 alloy showed the delayed peak aging time and higher peak hardness compared with those of the AZ91 alloy. The activation energies for ${\beta}$ precipitation calculated by means of Kissinger method increased from 71.4 to 85.6 kJ/mole by the addition of CaO, which implies that CaO plays a role in reducing ${\beta}$ precipitation rate in the AZ91 alloy.

• 대한안전경영과학회지
• /
• 제10권4호
• /
• pp.111-120
• /
• 2008

The combustion reaction of polypropylene was investigated using a thermogravimetric technique under an air atmosphere condition at several heating rates from 10 to $50^{\circ}C/min$. To obtain information on the kinetic parameters, the dynamic thermogravimetric analysis curve and its derivative were analyzed by a variety of analytical methods such as Kissinger, Friedman, Freeman-Carroll, Chatterjee-Conrad, Ozawa and Coats-Redfern methods. The comparative works for the kinetic results obtained from various methods should be performed to determine the kinetic parameters, because there are tremendous differences in the calculated kinetic parameters depending upon the mathematical method taken in the analysis.

• Elastomers and Composites
• /
• 제23권3호
• /
• pp.213-222
• /
• 1988

The thermal decomposition of poly(n-butyl methacrylate)(Pn-BMA) was studied using a dynamic and isothermal thermogravimetry in nitrogen gas with 50ml/min at several heating rates from 1 to $20^{\circ}C/min$, and at several heating temperature from 320 to $370^{\circ}C$. The mathematical techniques used for calculation of activation energy were Kissinger, Anderson, Chatterjee-Conrad, Friedman, Fuoss, Ozawa and isolthermal method. The range of activation energies obtained using the several techniques was between 43 and 51Kcal/mol except Chatterjee-Conrad and this range agreed with each other very well. The thermal degradation of Pn-BMA was considered to be carried out by main chain scission.

• 한국전기전자재료학회:학술대회논문집
• /
• 한국전기전자재료학회 1999년도 춘계학술대회 논문집
• /
• pp.548-551
• /
• 1999

The cure characteristics of metal particle filled DGEBA/MDA/SN/ zeolite epoxy resin composite system for EMI shielding were investigated by dynamic DSC run method and FT-lR spectroscopy. As the heating rate increased, the peak temperature on dynamic DSC curve increased because of the rapid cure reaction. From the straight line of the Kissinger plot, the curing reaction activation energy and pre-exponential factor could be obtained. As the post-curing time at 15$0^{\circ}C$ increased, the glass increased the glass transition temperature or the thermal stability increased. When the post curing time is too long, the system filled with metallic Al particle can be thermally oxidized by the catalytic reaction of metal filler and the thermal stability of the composite for the EMI shielding application may be decreased.