• Bulletin of the Korean Chemical Society
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• v.30 no.7
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• pp.1603-1606
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• 2009

A new 1D oxalato bridged compound Ni(en)(ox)-2$H_2$O, (ox = oxalate; en = ethylenediamine) has been hydrothermally synthesized and characterized by single crystal X-ray diffraction, IR spectrum, TG analysis, and magnetic measurements. In the structure the Ni atoms are coordinated with four oxygen atoms in two oxalate ions and two nitrogen atoms in one ethylenediamine molecule. The oxalate anion acts as a bis-bidentate ligand bridging Ni atoms in cis-configuration. This completes the infinite zigzag neutral chain, [Ni(en)(ox)]. The interchain space is filled by water molecules that link the chains through a network of hydrogen bonds. Thermal variance of the magnetic susceptibility shows a broad maximum around 50 K characteristic of one-dimensional antiferromagnetic coupling. The theoretical fit of the data for T > 20 K led to the nearest neighbor spin interaction J = -43 K and g = 2.25. The rapid decrease in susceptibility below 20 K indicate this compound to be a likely Haldane gap candidate material with S = 1.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.362-363
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• 2008

Well-defined o-$LiMnO_2$ cathode materials were synthesized using LiOH and $Mn_3O_4$ starting materials at $1050^{\circ}C$ in an argon flow by quenching method. The synthesized $LiMnO_2$ particles with crystalline phases were identified with X-ray diffraction (XRD, Dmax/1200, Rigaku). XRD results, demonstrated that the compound $LiMnO_2$ can be indexed to a single-phase material having the orthorhombic structure. In this paper, we analyzed the electrochemical performance of $LiMnO_2$/Li using solid polymer electrolyte and liquid electrolyte.

• Proceedings of the Korean Society of Dyers and Finishers Conference
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• 2008.04a
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• pp.190-191
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• 2008

In the presence of heat and oxygen, phosphorous compounds decompose to form water vapor and phosphorous oxides. The phosphorous oxides subsequently reat with the polymer matrix and dehydrate it, reforming phosphoric acids. These acids again decompose to reform water vapor and phosphorous oxides. Ultimately as the water available from normal combustion of hydrocarbons diminishes, the phosphorous oxide reat with hydrocarbon fragments to produce a very high melting point char at the interface between the polymer and the heat material. The chars, which contain phosphorous, rapidly dissipate heat energy and lose their glow. This antiglow property of phosphorous compound contributes to its availability as a flame retardant. In this study, the acrylated phosphorous compounds will be prepared and demonstrated as flame retardants.

• Elastomers and Composites
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• v.55 no.1
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• pp.40-45
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• 2020

In this study, the mechanical and flame-retardant properties of ethylene-propylene-diene-termonomer (EPDM) based rubber compounds and various other environmentally friendly inorganic flame retardants were investigated. Alumina trihydrate (ATH) and magnesium hydroxide (MDH) were used as inorganic flame retardants. The mechanical properties after thermal oxidation aging and the flame-retardant properties of the EPDM compounds were measured using a moving die rheometer, a universal testing machine, a compression set, and a UL 94 V flammability test. We focused on how the properties were affected by the type and amount of flame retardants. The results demonstrated that the optimal mechanical and flame-retardant V-0 grade properties were obtained at an ATH content of 200 phr.

• 한국신재생에너지학회:학술대회논문집
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• 2007.11a
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• pp.47-51
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• 2007

The present paper reports the life time prediction of Acrylonitrile-Butadiene rubber (NBR) fuel cell gasket materials as a function of operational variables like acid concentration, ageing time and temperature. Both material and accelerated acid-heat aging tests were carried out to predict the useful life of the NBR rubber gasket for use as a fuel cell stack. The acid ageing of the gasket compounds has been investigated at 120, 140 and $160^{\circ}C$, with aging times from 3 to 600 h and increasing acid ($H_2SO_4$) concentrations of 5, 6, 7 and 10 vol%. Material characteristics the gas compound such as cross-link density, tensile strength and elongation at break were studied. The hardness of the NBR rubber was found to decrease with decreasing acid concentration at both 120 and $140^{\circ}C$, but at $160^{\circ}C$ interestingly the hardness of the NBR rubber increased abruptly in a very short time at different acid concentrations. The tensile strength and elongation at break were found to decrease with increase in both the acid concentrate ion & temperature. The life time of the compounds were evaluated using the Arrhenius equation.

• Polymer(Korea)
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• v.30 no.5
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• pp.391-396
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• 2006

It has been reported that plasma treatments are used to modify surface properties of polymers such as adhesivity hydrophobicity and hydrophilicity. Using plasma treatment, interfacial pro-perty can be introduced to a polymer surface without affecting the desired bulk properties of a material. In this study, commercial polyamide66 (PA66) /polyphenylene (PPE) polymer was modified by plasma treatment under a various gas specious for elimination of organic compound and polymer surface property with hvdrophilicity. PA66/PPE polymer with hydrophilicity was treated by RF plasma vacuum system under a various parameter such as gas specious, processing time and partial pressure. Hydrophilicity of PA66/PPE was confirmed by calculation of the surface free energy from contact angle measurement. The highest surface free energy of $50.03 mJ/m^2$ with the lowest contact angle of $14^{\circ}$ was obtained at plasma process power of 100 W, treatment time of 2 min and $Ar/O_2$ gases of 100 and 200 sccm. Moreover the change of organic compounds on the polymer surface was analyzed by fourier transforms infrared spectrometry (FTIR).

• Elastomers and Composites
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• v.40 no.2
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• pp.93-103
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• 2005

In this study, surface treatment of the elastomeric matrix was investigated to develop a substituting material for steel dynamic damper of automobile. The key technology is to get ultra high density elastomeric compound in order to substitute steel dynamic damper. The optimum matrix material(chloroprene rubber) and filler(metal powder) were selected for this. The several properties of elastomeric compound were examined. According to the results, the $t_{s2}$ of filled elastomeric compound was decreased with increasing the filler loading whereas the $t_{90}$ was increased. Also, tensile strength and rebound resilience were decreased with filler loading. To solve the problem of high filler loading, the photo grafting technique was employed on elastomeric matrix. The degree of grafting was determined by FTIR-ATR. Also, the filler surface was modified by chemical etching and the surface morphology was examine by SEM. After chemical treatment of filler, the particle size analyzer was used to examined the particle size, size distribution, and morphology of the modified filler.

• Journal of the Korean Magnetic Resonance Society
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• v.20 no.1
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• pp.7-12
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• 2016

PTMEG(Polytetramethylene ether glycol) is a polymer compound widely used as a wide range of applications in the textile industry. PTMEG substance carrying various 1,800~2,000 molecular weight are mainly used as the raw material of the spandex production. Molecular weight and degree of polymerization value for 4 different PTMEG samples under pilot plant scale synthetic process were determined by a new quantitative NMR method. In NMR experiments, p-toluenesulfonic acid(TSOH) was used for external standard material of PTMEG quantitative analysis. were measuring The concentration of the primary standard TSOH was measured by UV/Vis spectroscopy. By using NMR peak assignments and the integral values of designated proton NMR peaks, We were able to measure the % composition of the synthetic PTMEG polymers, concentrations, molecular weight and the degree of polymerization that show the synthetic process of each manufacturing pilot plant. By utilizing a newly developed quantitative NMR method were able to obtain the molecular weight of PTMEG samples within 0.08 error % range.

• 한국정보디스플레이학회:학술대회논문집
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• 2007.08a
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• pp.628-631
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• 2007

We developed new green emitting materials based on the spiro moieties. The introduction of a spiro linkage into the structure of DJGH series lead to a reduction in crystallization tendency and an increase in glass transition temperature. they showed much better emitting efficiency and color purity than commercial host material $Alq_3$.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.475-478
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• 1999

The thermal properties of epoxy resin/siloxane for the electrical insulation were investigated by using dynamic DSC run method. As the heating rate increased, the peak temperature on dynamic DSC curve increased. From the linear relation on the Kissinger plot the curing reaction activation energy and pre-exponential factor could be obtained. The curing activation energy from the straight line of the Kissinger plot was 46.72 kJ/mol.