• 한국염색가공학회지
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• 제9권5호
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• pp.82-87
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• 1997

Modified polypropylene was made of melt blending using thermostable-filler and polypropylene polymers. Modified PP were characterized for the purpose of improving a thermal-property of PP polymer with the composition of 5wt %, 10wt % of thermostable-filler. The structure and thermal-property were determined from IR, DSC, TGA, and SEM instruments. From the results of this study, it found the following facts. Firstly, it was found that the modified PP was mixed with PP and thermostable-filler qualitativly. Secondaty, thermal property of modified PP was improved steadily according to increase of ratio of thermostable-filler.

• Journal of Pharmaceutical Investigation
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• 제41권3호
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• pp.179-184
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• 2011

This study aimed to confirm the effect of molecular weight (MW) in solid dispersion of carvedilol with poly-vinylpyrrolidone (PVP) of various MW. Solid dispersion of carvedilol with PVP was prepared by spray-drying method. Scanning electron microscopy (SEM) was used to analyze the surface of solid dispersion samples. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were used to analyze the crystalline of solid dispersion. Fourier transform infrared spectroscopy (FT-IR) was used to analyze the change of chemical structure characteristic of solid dispersion. DSC and XRD show that drug crystalline was changed. FT-IR revealed that chemical structure of solid dispersion comparing the chemical structure of drug was changed. The dissolution studies of solid dispersion presented at simulated gastric juice (pH 1.2). The dissolution rate of solid dispersion was dramatically enhanced than pure drug and the MW of PVP has an effect on the release property of carvedilol in solid dispersion. In conclusion, the present study has confirmed the effect of MW of PVP on release property of solid dispersion formulation of carvedilol with PVP.

• 한국염색가공학회지
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• 제22권1호
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• pp.43-50
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• 2010

The thermal treatment for carbon nanotube was applied to remove the water, metal catalyst and other impurities in carbon nanotube. The surface of carbon nanotube was changed into open structure with acid treatment by mixed solution of $HNO_3$ and $H_2SO_4$. The dispersion property of the functionalized and modified carbon nanotube was assessed with naked eyes by dispersing it in DMF. Carbon nanotube mixd polyurethane film was made to estimate the dispersion property by reflectance of the film with UV-Vis spectrometer. Also the internal structure of carbon nanotube was observed with SEM and TEM and thermal pyrolysis property of the carbon nanotube was measured by TGA and DSC. The surface modification of carbon nanotube by thermal and acid treatments improved the dispersion property of carbon nanotube/polyurethane mixed materials.

• 멤브레인
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• 제19권4호
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• pp.341-347
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• 2009

Poly propylene carbonate (PPC)와 cloisite 20B (PPC/C-20B)을 solution method를 통하여 합성하였고, 이를 통해 합성된 나노 조성물의 morphology, 열적 특성, 수분 흡수의 특성을 평가하였다. 나노 조성물의 구조는 X-ray diffraction (XRD) 로 확인하였고, 열적 특성은 thermal gravimetric analysis (TGA)와 differential scanning calorimetric (DSC)를 이용해 분석하였다. TGA와 DSC의 결과를 통해 나노 조성물은 기존의 PPC에 비해 높은 열적 안정성을 가짐을 확인할 수 있었다. DSC측정에서 5 wt%의 clay를 포함한 nanohybrid의 유리전이온도는 순수한 PPC의 $21^{\circ}C$에서 $30^{\circ}C$로 $9^{\circ}C$ 증가하였고, TGA 측정을 통해 확인한 열분해온도($T_{d50%}$)는 순수 PPC에 비해 $23^{\circ}C$가 높아졌음을 확인하였다. 또한 PPC 나노 조성물의 수분 흡수량은 기존의 PPC에 비해 상당히 감소하였다. 이는 clay의 PPC matrix 구조 내에 존재함으로 인해 수분 흡수를 감소시킨 것으로 해석할 수 있다. 수분 흡수는 코팅 막의 분해를 유발하고 물리적, 기계적 성능에 영향을 미친다. 따라서 나노 조성물로 인한 PPC의 열적 안정성, 수분흡수도 향상은 PPC의 사용과 실제 공정에 중요한 변수로 작용할 수 있다.

• 한국재난정보학회 논문집
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• 제19권3호
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• pp.532-544
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• 2023

연구목적: 신규로 사용되는 바이오연료를 기존 연료와 혼합하여 사용하는 경우 발생하는 위험성과 물성 변화를 열분석 방법(DSC, TGA)을 사용하여 화학 화재의 원인물질의 위험성을 확인하고, 평가할 방법과 그에 따른 물질의 위험성 관련 데이터를 확보함으로써 화재 원인 감식과 감정에 활용하기 위함이다. 연구방법: 본 실험에 사용된 연구 방법으로는 시차주사열량계(DSC : Differential Scanning Calorimeter)에 의하여 피크의 위치, 모양, 개수, 피크의 면적으로부터 열량 변화의 정량적인 정보를 통하여 열유속 차이(Difference in heat flux)를 측정하였고, 열중량분석(TGA : Analyzer)을 시행함으로써 특정한 온도에서 분해열 등에 의해 발생한 무게 변화를 연속적으로 측정하였다. 연구결과: 먼저 열 유속의 그래프에서 물질의 끓는점과 물질이 가지고 있는 고유 특성치 또는 분해에 필요한 에너지를 확인할 수 있다. 둘째 바이오디젤의 함량이 증가할수록 많은 피크를 확인 할 수 있었다. 셋째 비점이 낮은 물질들이 함유하고 있다는 것을 분석 결과로 확인할 수 있었다. 결론: 현재 새로운 에너지원으로 사용되고 있는 바이오디젤의 위험성을 다양한 물리·화학적 분석기법(DSC+TGA)을 통하여 사용함으로써 물질의 물적 위험성을 평가할 수 있음을 보여주었다. 아울러 본 연구의 시험방법별 차이의 비교와 실험에 대한 노하우를 축적하고 활용한다면 향후 위험물의 물성 연구와 물질 위험성 평가 연구에 있어 도움이 되리라 기대한다.

• 한국세라믹학회지
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• 제37권5호
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• pp.459-465
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• 2000

3CaO.3Al2O3.CaSO4(C4A3)clinker was prepared by solid state reaction and then its hydration property was investigated. C4A3 clinker was fired at various temperatures in the range of 700~135$0^{\circ}C$. The hydration of it was studied by XRD, DSC, Solid-state 27Al MAS NMR and SEM. According to the results, the Ca4A3 clinker was produced by reacting calcium aluminates with CaSO4 and Al2O3 and C4A3 was formed as a main phase after calcining at 120$0^{\circ}C$. The hydration products were mainly calcium monosulfoaluminate hydrate and Al(OH)3, and they were produced after 2hrs of hydration. However the hydration rate was about 74% at 3days.

• Journal of Welding and Joining
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• 제33권5호
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• pp.31-34
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• 2015

Microstructure and tensile property in the weld heat-affected zone (HAZ) of austenitic Fe-Mn-Al-C low density steels were investigated through transmission electron microscopy analysis and tensile tests. The HAZ samples were prepared using Gleeble simulation with high heat input welding condition of 300 kJ/cm, and the HAZ peak temperature of $1200^{\circ}C$ was determined from differential scanning calorimetry (DSC) test. The strain- stress responses of base steels showed that the addition of V improved the tensile and yield strength by grain refinement and precipitation strengthening. Tensile strength and elongation decreased in the weld HAZ as compared to the base steel, due to grain growth, while V-added steel had a higher HAZ strength as compared than V-free steel.

• 한국분말재료학회지
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• 제10권1호
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• pp.34-39
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• 2003

Porous TiNi bodies were produced by Self-propagating High-temperature Synthesis (SHS) method from a powder mixture of Ti and Ni. Porosity, pore size and structure, mechanical property, and transformation temperature of TiNi product were investigated. The average porosity and pore size of produced porous TiNi body are 63% and $216\mutextrm{m}$, respectively. XRD analysis showed that the major phase of produced TiNi body is B2 phase. Its average fracture strength and elastic modulus measured under dry condition were $22\pm2$ MPa and $0.18\pm0.01$GPa, respectively. It could be strained up to 7.3 %. The transformation temperatures determined by DSC showed the $M_s$ temperature of $67^{\circ}C$ and $A_f$ temperature of $99^{\circ}C$.

• Bulletin of the Korean Chemical Society
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• 제30권3호
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• pp.657-660
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• 2009

The surface of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ cathode particle was modified by lanthanum based oxide to improve electrochemical property and thermal stability. The XRD pattern of surface layer was indexed with that of $La_4NiLiO_8$. The discharge capacity of modified electrode was higher than that of pristine sample, specially at fast charge-discharge rate and high cut-off voltage. In the DSC profile of the charged sample, the generation of heat by exothermic reaction was decreased by surface modification. Such enhancement may by attributed to the presence of stable lanthanum based oxide, which effectively suppressd the reaction between electrode and electrolyte on the surface of $Li[Ni_{0.8}Co_{0.15}Al_{0.05}]O_2$ electrode.

• Elastomers and Composites
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• 제35권1호
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• pp.19-28
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• 2000

본 연구에서는 기존 외국제품들과의 물성 비교를 통해 부가중합형 실리콘 인상재를 개발하기 위한 기초연구를 수행하였다. IR과 EDX를 이용한 인상재들의 화학적 분석, DSC와 TGA를 이용한 열적거동분석, 접촉각, 점도, 가교특성 및 기계적특성 등의 분석을 수행하여 본 연구에서 개발된 제품의 고무인상재로의 응용 가능성을 평가하였다. 기초연구 결과에 따르면 인상재에 요구되는 모든 물성을 만족하는 제품은 없었지만, 본 연구에서 개발된 인상재의 경우 인장물성 및 가교밀도 특성이 상대적으로 우수하여 인상 채득시 요구되는 기계적 특성에는 가장 잘 부합하였다. 그러나 향후 친수성 계면활성제 도입을 통한 젖음성 향상, 온도와 경화시간과의 상관관계 확립, 정확한 체적변화 및 인열강도 개선 둥의 추가적인 물성 향상이 필요한 것으로 판단되었다.