• Journal of Advanced Marine Engineering and Technology
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• v.28 no.6
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• pp.962-971
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• 2004

This paper has dealt with thermo-physical properties of microencapsulated phase change material slurry as a latent heat storage material having a low melting point. The measured results of the thermo-physical properties of the test microencapsulated phase change material slurry, those are, density, specific heat, thermal conductivity and viscosity, were discussed for the temperature region of solid and liquid phases of the dispersion material (paraffin). The measurements of these properties of microencapsulated phase change material slurry have been carried out by using a specific-gravity meter, a water calorimeter, a differential scanning calorimeter(DSC), a transient hot wire method and rotating type viscometer, respectively. It was clarified that the additional properties law could be applied to the estimation of the density and specific heat of microencapsulated phase change material slurry and also the Euckens equation could be applied to the estimation of the thermal conductivity of this slurry.

• Journal of the Korean Society of Safety
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• v.13 no.4
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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.

• Journal of Sericultural and Entomological Science
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• v.49 no.2
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• pp.77-80
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• 2007

Silk fibroin/poly (vinyl pyrrolidone) conjugates were prepared and characterized through differential thermal calorimeter and thermogravimetry. The glass transition temperature (Tg) of poly (vinyl pyrrolidone) was not changed by reaction with silk fibroin. However, abnormal exothermic peak was observed at the silk fibroin/poly (vinyl pyrrolidone) conjugates. Thermogravimetric analysis showed that thermal stability of silk fibroin was relatively increased by reaction with PVP.

• Composites Research
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• v.24 no.4
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• pp.5-10
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• 2011

As environmental pollution getting worse, biodegradable materials have been drawn more attention than ever. In this study, polylactic acid (PLA)/carbon nanotubc (CNT) nanocomposites were manufactured via extrusion molding and injection molding, In order to change the crystallinity, annealing treatment was done for different time span, Crystallization kinetics of PLA was analyzed by differential scanning calorimeter (DSC), and it was confirmed that a proper amount of CNT can increase the crystallization rate of PLA. In addition, the presence of CNT significantly accelerates the hydrolytic degradation rate of PLA, however, it decreases with the increase of crystallinity. The reason is that degradation may occur in the PLA/CNT interface easily, and the molecular structure of the composite becomes dense with the increase of crystallinity.

• Applied Chemistry for Engineering
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• v.20 no.4
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• pp.459-463
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• 2009

In this study, physical properties of poly(vinyl acetate-co-ethylene) (VAE) emulsion were investigated by adding different amounts of di-butyl phthalate (DBP) which is a common plasticizer of VAE. The glass transition temperature $(T_g)$ of the dried plasticized VAE emulsion film, which measured by Differential Scanning Calorimeter, was decreased with increasing the DBP contents while the viscosity of the plasticized VAE emulsion was increased with the DBP contents. These results suggest that the plasticizer in the dried VAE film can prevent the strong interaction between chains, resulted by the decrease of $T_g$. In the emulsion, however, the particle sizes were swelled by the penetration of plasticizers and then its viscosity increased with the DBP content. When the DBP was added, the mechanical properties of the plasticized VAE films, such as tensile strength, elongation and creep resistance, were decreased while the water resistance was increased.

• Polymer(Korea)
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• v.25 no.5
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• pp.617-624
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• 2001

The core-shell composite latexes were synthesized by stage emulsion polymerization of methyl methacrylate (MMA) and styrene (St) with ammonium persulfate after preparing monomer pre-emulsion in the presence of anionic surfactant. However, in preparation of core-shell composite latex, several unexpected results are observed, such as, particle coagulation, low degree of polymerization, and formation of new particles during shell polymerization. To solve the disadvantages, We study the effect of initiator concentrations, surfactant concentrations, and reaction temperature on the core-shell structure of polymethyl methacrylate/polystyrene and polystyrene/polymethyl methacrylate. Particle size and particle size distribution were measured using particle size analyzer, and the morphology of the core-shell composite latex was determined using transmission electron microscope. Glass temperature was also measured using differential scanning calorimeter. To identify the core-shell structure, pH of the two composite latex solutions were measured.

• Journal of the Korean Institute of Gas
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• v.18 no.3
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• pp.31-37
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• 2014

The aim of this work is to provide new experimental data on the pyrolysis characteristics and the minimum ignition energy (MIE) by using the same high-density polyethylene (HDPE) powder in domestic HDPE dust explosion accident. To evaluate the explosion sensitivity of HDPE, thermo-gravimetric analysis (TGA), differential scanning calorimeter (DSC) and MIE apparatus (MIKE-3, K$\ddot{u}$hner) was conducted. The measurements showed the volume median diameter of $61.6{\mu}m$ but the particle number density of 98 % in the range $0.4{\sim}4{\mu}m$. The ignition temperature from the results of TGA and DSC in HDPE dust layers was observed in the range of $380{\sim}490^{\circ}C$. MIE was measured under 1 mJ in the HDPE dust concentration of $1200{\sim}1800g/m^3$, it was found that the ratio of particle number density in the range $0.4{\sim}4{\mu}m$ was very high (98%).

• The Korean Journal of Pharmacology
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• v.26 no.1
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• pp.77-82
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• 1990

The effects of phenothiazine derivatives and calcium on the thermotropic phase transition of bilayers in dipalmitoyl phosphatidylcholine (DPPC) and dipalmitoyl phosphatidic acid (DPPA) liposomes were investigated with differential scanning calorimeter (DSC). Bilayers underwent an abrupt organizational changes at a characteristic temperature when heated. Such temperature-dependent transition was particularly striking and sharp in the bilayers prepared from pure phospholipids. The ability of phenothiazine derivatives to modify the phase transition of phospholipids liposomes was measured by a broadening of the phase transition profile, that transition began to appear at lower temperature than which occurs in untreated liposomes. Calcium ion caused a large upward shift in the transition temperature of DPPC:DPPA (34:66mol%) liposomes. When the liposomes were first incubated with calcium ion followed by phenothiazine derivatives, disappearance of the broad curve centering at $73^{\circ}C$ indicated displacement of calcium ion by phenothiazine derivatives at the anionic site. It is supposed that calcium ion and phenothiazine derivatives might compete with each other on the head group of acidic phospholipid.

• Nuclear Engineering and Technology
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• v.8 no.2
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• pp.81-88
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• 1976

A flash method for measuring the unknown thermal property (the density, specific heat, or thermal diffusivity could be chosen as unknown) is described. The thermal diffusivity of UO$_2$ fuel samples is obtained from room temperature (300 K) to high temperature (1400 K). The specific heat is measured using a commercially available differential scanning calorimeter from room temperature to 500 K. The thermal conductivity of UO$_2$ fuel samples is calculated from the density, thermal diffusivity, and specific heat at constant pressure. The present results are in complete agreement with the usual trends for the thermal conductivity of dielectric materials, in which impurity levels are very important at low temperatures but become relatively unimportant at high temperatures. In addition, the thermal diffusivity values at room temperature are reexamined by measuring the thermal diffusivity of several UO$_2$ fuel samples with same level of doped Gd$_2$O$_3$.

• Applied Chemistry for Engineering
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• v.3 no.1
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• pp.111-118
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• 1992

The curing acceleration of epoxy/amine system was investigated by using differential scanning calorimeter(DSC), The epoxy, diglycidylether of bisphenol A (DGEBA) was cured with methylene dianiline (MDA) with or without accelerators. Two kinds of accelerators were tested for the study ; tris(dimethylaminomethyl)phenol (DMP - 30) and 3 - (3,4 - dichlorophenyl)-1, 1-dimethylurea (DIURON). Heats of reaction and glass transition temperatures ($T_g$) of the cured epoxy system were analyzed by DSC along with the estimation of activation energy by the dynamic DSC studies. It was found that DMP - 30 is more effective accelerator than DIURON which showed faster curing and lower activation energy.