• Title/Summary/Keyword: differential scanning calorimetry(DSC)

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Effect of Cyclic Olige(ethylene Terephthalate) on the Crystallization of Poly(ethylene Terephthalte) -Isothermal Crystallization- (고리올리고에틸렌 테레프탈레이트가 폴리에틸렌 테레프탈레이트의 결정화 속도에 미치는 영향 -등온 결정화-)

  • 류동일;하완식
    • Textile Science and Engineering
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    • v.24 no.4
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    • pp.1-8
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    • 1987
  • Poly(ethylene terephthalate)(PET) with different cyclic oligomer contents was crystallized under isothermal condition. Crystallization rate has been determined by differential scanning calorimetry(DSC). All the data obtained through DSC were treated with Avrami's equation. Some parameters for crystallization kinetics were derived. It was found that the cyclic oligomer contained in PET retards the crystallization rate. This finding was confirmed by observing the morphology of PET with polarizing microscope.

A Study on the Physical Properties of Molten Polyester-Polyamide Blended Systems (Polyester와 Polyamide의 혼합용융에 의한 물성변화에 관한 연구)

  • 조순채;유영국
    • Textile Science and Engineering
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    • v.25 no.3
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    • pp.35-46
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    • 1988
  • The dynamic properties of molten poly(ethylene terephthalate) / polyamide 6 blend systems have been studied in terms of blending ratio, frequency, time, temperature, and shear strain. The dynamic properties were measured with a Rheometrics Dynamic Spectrometer(RDS). On the whole, the rheological properties of the blend systems such as dynamic viscosity(n*), storage and loss moduli(G' and G"), and activation energy of flow were varied with blending compositions. Such thermal properties as glass transition temperature(Tg), crystallization temperature on heation(Tch), crystallization temperature on cooling(Tcc) and melting temperature(Tcc) have also been investigated by using a using a differential scanning calorimetry(DSC).

Polymorphism of Doxazosin Mesylate

  • Sohn Young-Taek;Lee Yoon-Hee
    • Archives of Pharmacal Research
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    • v.28 no.6
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    • pp.730-735
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    • 2005
  • Nine polymorphic modifications of doxazosin mesylate have been obtained by recrystallization in organic solvents under variable conditions. Different polymorphs of doxazosin mesylate were characterized by powder X-ray crystallography diffractometry (PXRD), differential scanning calorimetry (DSC), and thermogravimetric analysis (TG). Transformation of Form 1 and Form 2 was not occurred in three relative humidities ($0\%$, $51\%$, and $99\%$) at 20$\pm$0.5 for 30 days.

A Study on the Effects of Brassica oleracea L. Fractions on the Membrane Fluidity of the Liposomal Phospholipid Membranes

  • Park, Yun-Ja;Bae, Song-Ja
    • Proceedings of the PSK Conference
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    • pp.221.1-221
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    • 2003
  • This research was designed to investigate the effects of Bassica oleracea L. (BO) fractions on the membrane fluidity of the liposomal phospholipid membranes. The sample BO was extracted and fractionated to six different types. methanol(BOM), hexane(BOMH). ethylether(BOMEE), etylacetate(BOMEA), butanol(BOMB) and aqueous(BOMA) fractions. The fluidity of dipalmitoylphosphatidylcholine(DPPC) liposomal membranes incorporated with BO fraction was measured by means of high-sensitivity differential scanning calorimetry(DSC). (omitted)

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Synthesis and Characterization of Novel Fused Aromatic Semiconductors

  • Zhao, Qinghua;Park, Jong-Won;Kim, Yun-Hi;Kwon, Soon-Ki
    • 한국정보디스플레이학회:학술대회논문집
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    • pp.1193-1197
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    • 2006
  • The novel oligomers were synthesized by Grignard reaction, the suzuki coupling reaction, etc. The oligomers were characterized by Infrared (IR), Mass spectrometer (MS). Their thermal properties were investigated by differential scanning calorimetry (DSC) and Thermogravimetric analysis (TGA). The new oligomers showed high thermal stability above $300^{\circ}C$.

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A Study on Thermal Behaviors of Expanded Graphite/Erythritol Composites (팽창흑연/에리스리톨 복합체의 열적거동에 관한 연구)

  • Choi, Bo-Kyung;Choi, Woong-Ki;Kuk, Yun-Su;Kim, Hong-Gun;Seo, Min-Kang
    • Applied Chemistry for Engineering
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    • v.25 no.5
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    • pp.463-467
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    • 2014
  • In this paper, the thermal behaviors of expanded graphite(EG)/erythritol composites with different contents of EG were studied. The surface and structure properties of the composites were determined by using scanning electron microscope (SEM), transmission electron microscope (TEM), and X-ray diffraction (XRD), respectively. The thermal properties were investigated by differential scanning calorimetry (DSC) and thermal conductivity (TC). As experimental results, the thermal conductivity of the composites increased with increasing the EG content. However, the latent heat was somewhat decreased in the presence of EG. We could concluded that EG was highly promising materials for improving the heat transfer enhancement and energy storage capacity of phase change materials (PCMs).

Plasma-Surface-Treatment of Nylon 6 Fiber for the Improvement of Water-Repellency by Low Pressure RF Plasma Discharge Processing (나일론 6 섬유의 발수성 향상을 위한 RF 플라스마 표면처리)

  • Ji, Young-Yeon;Jeong, Tak;Kim, Sang-Sik
    • Polymer(Korea)
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    • v.31 no.1
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    • pp.31-36
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    • 2007
  • It has been reported that the surface properties of the plasma treated material were changed while maintaining its bulk properties. In this study, surface modification of nylon fiber by plasma treatment was tried to attain high water-repellency Nylon fiber was treated with RF plasma under a vacuum system using various parameters such as gas specious, processing time and processing power. Morphological changes by low pressure plasma treatment were observed using scanning electron microscopy (SEM) and atomic force microscopy (AFM). Moreover, the mechanical and inherent properties were analyzed by tensile strength, differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA). The high water-repellency property of nylon fiber was evaluated by a water-drop standard test under various conditions in terms of aging effect. The results showed that the water-repellency of plasma-surface-treated nylon fiber was greatly improved compared to untreated nylon fiber.

Comparison of Colorless and Transparent Polyimide Films with Various Amine Monomers (다양한 아민 단량체를 이용한 무색 투명 폴리이미드 필름의 특성비교)

  • Kim, Youngmin;Chang, Jin-Hae
    • Applied Chemistry for Engineering
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    • v.23 no.3
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    • pp.266-270
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    • 2012
  • A series of polyimide was prepared by reacting 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA) as the anhydride monomer and 2,2'-bis(trifluoromethyl)benzidine (TFB), 2,2'-bis(3-aminophenyl)hexafluoropropane (BAFP), 2,2'-bis(3- amino- 4-methylphenyl) hexafluoropropane (BAMF), bis(3-aminophenyl)sulfone (APS), p-xylyenediamine (p-XDA), or m-xylyenediamine (m-XDA) as the amine monomer in N,N-dimethylacetamide (DMAc). Colorless and transparent polyimide (PI) films were obtained by casting the poly(amic acid)s (PAAs) solution at various heat treatment temperatures. The thermal properties of the PI films were examined using differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and thermomechanical analysis (TMA) and the mechanical properties were investigated using universal tensile machine (UTM), Their optical transparencies were also investigated using ultraviolet-visible (UV-vis.) spectrophotometry and colorimetry. The yellow index (YI) and coefficient of thermal expansion (CTE) values of all PIs were in the range 0.98~2.76 and 25.73~55.23 $ppm/^{\circ}C$, respectively.

Differential Scanning Calorimetric Study of Amylose-lipid Complex and Amylose Content in Rice Starch (쌀 전분의 Amylose-lipid Complex 의 DSC 특성과 Amylose 정량)

  • Ko, Jae-Hyung;Park, Kwan-Hwa
    • Korean Journal of Food Science and Technology
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    • v.21 no.4
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    • pp.556-561
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    • 1989
  • Thermal properties of amylose-lysolecithin (AL) complex, amylose content and effect of lysolecithin on the gelatinization of rice starch were investigated by Differential Scanning Calorimetry (DSC). The melting temperature of AL complex was near to $108.5^{\circ}C$ and the melting enthalpy was about 1.0cal/g. The gelatinization temperature of rice starch was not affected by adding lysolecithin. However, the enthalpy of gelatinization was decreased. The amylose contents in rice varieties were calculated from melting enthalpy of AL complex. The amylose contents for Indica and Japonica types of rice were in the range of 16-19%, which were in good agreement with those determined by iodine binding method. Significant differences were not observed in the amylose contents between Indica and Japonica varieties.

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