• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 1994년도 춘계학술대회 논문집
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• pp.30-33
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• 1994

This paper studies on the effect of DSC(Differential Scanning Calorimeter) analysis condition on the glass transition temperature of silica filled epoxy network polymer used for ultra-high voltage apparatus. The effects of temperature scanning rate specimen size and gas flow rate on measured glass transition temperature have been studied in order to select optimum thermal analysis condition.

• 한국안전학회지
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• 제16권2호
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• pp.75-79
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• 2001

For handling and storage of reactive chemicals, the hazard evaluations have been extremely important. In the chemical industry, the most concerns are focused on the thermal harzards such as runaway reactions and thermal decompositions, which are mostly governed by thermodynamics and reaction kinetics or these reactive chemical in the system. This study no investigated the thermal decomposition characteristics of nitrophenylhydrazine isomers by using differential scanning calorimeter(DSC) and accelerating rate calorimeter(ARC). Experimental results showed that exothermic onset-temperatures in nitrophenylhydrazine(NPH) isomers were about 160-$210^{\circ}C$ by DSC and 100-$150^{\circ}C$ by ARC. The decomposition temperature acquired by ARC was about 50-$60^{\circ}C$ lower than that by DSC. Reaction heats were about 40-100cal/g by DSC and 330-750ca1/g by ARC. While ortho isomer of NPH show two distinct exothermic peaks, para isomer shows a single peak in DSC curves. The first exothermic peak for 2-NPH is mainly due to intramolecular dehydration forming 1-hydroxybenzotriazole(HOBT) and the second exothermic peak is mainly due to the decomposition of HOBT formed in the first step of decomposition. The exothermin peak in the DSC curve for 4-NPH is mainly due to dissociation of hydrazino and nitro groups.

• 한국생산제조학회지
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• 제21권6호
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• pp.976-981
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• 2012

In this study, hardness, microstructure and temperature of glass transition are measured respectively by using SEM (Scanning electron microscope) and DSC (Differential scanning calorimeter) to analyze the effects on material properties by after-curing in the epoxy resin. As the result of hardness test according to the after-curing conditions, the higher the temperature of after-curing, hardness and heat resistance are, the higher hardness is. As a result of microstructure for each specimen by SEM, it could be confirmed that the specimen with after-curing has more dense fracture surface. It is also found that temperatures of glass transitions by DSC are comparatively higher in the specimens with after-curing, and the differences between after-curing conditions are negligible.

• Elastomers and Composites
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• 제48권4호
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• pp.276-281
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• 2013

acrylic polyol로 개질한 polyester형 polyurethane foam을 quasi prepolymer법으로 제조하였다. 열적 및 동적 기계적 성질은 thermal gravimetric analysis 및 dynamic mechanical analysis에 의하여 분석하였다. 또한 유리전이온도는 differential scanning calorimeter로 측정하였다. Acrylic polyol 함량이 증가함에 따라 TGA에 의해 측정한 열적 안정성은 약간 감소하였다. 그리고 acrylic polyol 함량이 증가함에 따라 저장 탄성률은 증가한 반면에 tan delta 값은 감소하였다.

• 한국추진공학회지
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• 제22권2호
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• pp.59-65
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• 2018

AP(Ammonium Perchlorate, $NH_4ClO_4$)를 포함하는 복합화약조성의 등온가열시험시, 일정 순도 이하의 AP를 사용하는 경우 "bulged"현상으로 인해 등온가열시험 결과를 얻을 수 없었다. 본 연구는 품질 혹은 순도에 따른 AP의 열적 안정성 차이에 대해 규명하기 위해 LOT 별 AP에 대해 DSC 결과를 분석하고, 그 분석결과를 등온가열시험 결과 및 ARC결과와 비교분석하였다. 또한 순도가 낮은 AP에 대해서는 재결정을 통해 포함된 불순물을 제거한 후 분석한 결과, 열적 안정성이 높아졌음을 확인하였다. DSC 고압팬을 사용하여 AP 순도를 결정하는 정량적 분석방법을 확립하였다.

• 한국안전학회지
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• 제25권3호
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• pp.61-65
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• 2010

Most of the chemical reactions performed in the chemical industry are exothermic, meaning that thermal energy is released during the reaction. It is also important to understand the thermal hazards such as thermal stabilities and runaway reactions, which are governed by thermodynamics and reaction kinetics of the mixed materials. The paper was described the evaluation of thermal behavior caused by an exothermic batch process in manufacture of the vinyl acetate resin. The aim of the study was to evaluate the thermal stabilities of raw materials with operating conditions such as a reaction inhibitor, heating rate, reaction atmosphere and the mount of methanol charged in the vinyl acetate polymerization process. The experiments were performed in the differential scanning calorimeter(DSC), C 80 calorimeter, and thermal screening unit($TS^u$). It was suggested that we should provide the thermal characteristics for raw materials to present safe precautions with operating conditions in the vinyl acetate polymerization process.

• 한국안전학회지
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• 제13권4호
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• pp.180-185
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• 1998

The evaluation of thermal and pressure hazard of chemicals on the manufacturing, transporting and storaging is important in the chemical industry for safety. In this study, the thermal decomposition characteristics of intermediate of Saccharin were investigated by using Accelerating Rate Calorimeter(ARC) and Differential Scanning Calorimeter(DSC). Experimental results showed that decomposition temperatures in p-TSA were about 280~$318^{\circ}C$ by DSC and $201^{\circ}C$ by ARC. In case of o-TSA were about $336^{\circ}C$~$360.8^{\circ}C$ by DSC and $299^{\circ}C$ by ARC. The decomposition temperature acquired by ARC was about $70^{\circ}C$ lower than that by DSC. The exothermic runaway reaction in case of p-TSA occured in 598 minute and o-TSA in 5 minute. For the safety in the chemical industry, we should consider the ARC data as well as DSC data in the handling and design of process.

• 한국식품영양학회지
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• 제24권4호
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• pp.740-745
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• 2011

Ohmic heating uses electric resistance heat which occurs equally and rapidly inside food when an electrical current is passed throught. In this study, we observed the physical & chemical characteristics changes which occurs in soybean protein during heating denaturation by using ohmic and conventional heating. After the ohmic heating process, we could not find any change of the primary protein structure in the denaturated soy protein samples. However, the rate of imbibed water(RIW) of the ohmic samples was 2 times faster than that of the conventional samples. Also the ANS-surface hydrophobicity was decreased, which is very closely related to RIW. In the differential scanning calorimeter(DSC) analysis result, all 7S soyprotein fraction samples were completely denaturated by ohmic and conventional heating. However, the 11S samples were completely denatured only by ohmic heating. According to the DSC result, we decided that soyprotein was damaged by temperature and electrical current during ohmic heating. The damage of electrical current was a cause of the characteristic changes.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.513-516
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• 2017

화약 기반 소자 (PMD)에서 장기간 보관을 하게 되면 소자 안에 있는 화약이 노화되어 폭발력에 변화가 생기기 때문에, 일정 기간이 지나면 폐기 처분을 하게 된다. 그렇기 때문에 PMD 안에 사용하는 화약은 자발적 혹은 외부적 요인에 대하여 화학적 및 물리적으로 안정해야 한다. 기존에 사용되는 화약으로서 $BKNO_3$과 THPP를 대표적으로 이용하기 때문에, 이 화약들을 기반으로 하여 열역학적 및 속도론적 분석을 실시하였다. Differential scanning calorimeter (DSC)를 이용하여 발열량과 반응속도를 분석하였는데, 그 결과 THPP에서는 열량 차이 및 반응속도에 큰 변화가 보이지 않았다. 추가적으로, 노화에 직접적으로 연관되는 산화막 형성을 확인하기 위하여 XPS 및 TEM-EDS 분석하였는데, 열적 분석 결과와 상응하는 결과로서 산화막이 관측 되지 않았다. 이는 THPP가 장기 안정성 측면에서 가장 유명한 화약이라고 판단 할 수 있다.

• 공업화학
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• 제3권1호
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• pp.111-118
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• 1992

시차주사열량계(DSC)를 이용하여 에폭시 - 아민계의 경화 촉진을 연구하였다. 비스페놀 A의 디글리시딜에테르(DGEBA)든 촉진제와 함께 또는 촉진제 없이 메틸렌디아닐린(MDA)으로 경화시켰다. 본 연구를 위하여 트리스(디메틸아미노메틸페놀(DMP - 30)과 3 - (3,4 - 디클로로페닐) - 1,1 - 디메틸우레아(DIU-ON) 두 종류의 촉진제를 사용하였는데 경화시의 발열량, 유리전이온도($T_g$) 및 동적 DSC에 의한 활성화에너지 계산에 의해 DMP - 30이 빠른 경화 속도 및 낮은 활성화에너지를 보여 DIURON보다 양호한 촉진제임을 알 수 있었다.