• Polymer(Korea)
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• v.37 no.4
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• pp.494-499
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• 2013

Modified polypropylene (m-PP) was fabricated by furfuryl sulphide (FS) as branching agent and m-PP/nano-filler composites were prepared with silicate and multi-walled carbon nanotube (MWCNT), using a twin screw extruder. The chemical structures and thermal properties of the m-PP were investigated by FTIR and DSC. The chemical structure of the m-PP was confirmed by the existence of =C-H stretching peak of the branching agent at 3100 $cm^{-1}$. There was no district change in melting temperature in case of m-PP, but a certain increase in crystallization temperature was notified and the increase was in the range of $10-20^{\circ}C$. The rheological properties, filler dispersion and foaming behaviors of the m-PP/nano-filler composites were investigated by dynamic rheometer, X-ray diffractometer (XRD) and scanning/transmission electron microscope (SEM/TEM). m-PP/nano-filler composites showed a high complex viscosity at a low frequency, an increase in melt elasticity, and a high shear thinning effect. Compared to pure PP, m-PP and m-PP/nano-filler composites were sufficient to enhance the foaming behavior.

• Proceedings of the Materials Research Society of Korea Conference
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• 2009.11a
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• pp.18.1-18.1
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• 2009

금속 다공체는 자동차, 선박, 건축 등의 분야에서 구조물이나 충격흡수제 등으로 응용되고 있는데 이들은 일반 금속 구조물에 비해 가볍고 플라스틱에비해서는 강한 장점을 지닌다. 현재 사용되고 있는 대부분의 금속 다공체는 발포 주조공정으로 제조된 알루미늄으로서, 철계 합금에 비해 가벼운 장점을 갖지만 강도가 상당히 떨어지고 가격이 높은 단점을 가진다. 따라서 본 연구에서는 알루미늄 대신 철계 합금으로 다공체를 제조하고자 하였고 제조방법으로는 주조공정 대신 분말공정을선택하였다. 분말공정은 구형 스티로폼을 금속분말 슬러리로 코팅한 후 스티로폼을 제거하여 낱개의 금속중공체(Metallic Hollow Sphere)를 제조하고 이렇게 제조된 중공체를 뭉쳐 성형함으로써최종 형상의 다공체를 제조하는 방법이다. 이 방법으로 제조된 다공체는 주조공정으로 제조된 다공체보다높은 강도를 나타내며 낱개의 중공체는 성형공정을 거치지 않고 필터나 충진재 등의 새로운 용도로 활용될 수 있다.

• Proceedings of the Korea Concrete Institute Conference
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• 1998.10a
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• pp.362-367
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• 1998

The purpose of this study is to examine the influences of polystyrene content and St/UP on the setting shrinkage and strengths of polymer mortar with waste expanded polystyrene resin as a shrinkage-reducing agent, and to recommend the optimum binder formulations for product of low-shrinkage polymer mortar. In this paper, polymer mortar is prepared with waste expanded polystyrene content and St/UP, and tested for setting shrinkage, flexural and compressive strengths. From the test results, irrespective of increasing of waste expanded polystyrene resin, the strengths reduction of polymer mortar with waste expanded polystyrene(EPS) resin is not recognized. And the setting shrinkage is reduced with EPS resin content. The waste expanded polystyrene resin as a shrinkage-reducing agent can be used in the same manner as commercial polystyrene resin. In this study, we can obtain the optimum mix proportions of polymer mortar using EPS resin.

• Proceedings of the Korean Society of Applied Pharmacology
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• 2000.04a
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• pp.20-25
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• 2000

아세트아미노펜(파라세타몰)은 p-aminophenol 유도체로서 (그림 1) 두통, 치통, 신경통 등의 통증에 널리 사용되는 해열진통제인데 아스피린과 같은 정도의 해열 진통 효과를 나타내며, 이것은 중추신경계의 체온조절 중추에 작용하여 피부혈관을 확장함으로써 열의 확산을 증가시키는 해열작용과 시상 및 대뇌피질에의 통각역치를 높여 진통작용을 하는 것으로 추정 된다. 아세트아미노펜은 백색의 결정 또는 결성성 가루로 물에 조금 녹고 메탄올 또는 에탄올에 잘 녹으며 수산화나트륨 시액에 녹고 에텔에는 매우 녹기 어렵다 (표1). 대한약전에서는 정제가, 미국약전에는 캅셀제, 좌제, 경구현탁액제, 발포성 건조시럽, 정제 등이 수재되어 있고, 세계 각국에서 OTC 제품으로 1정당 160mg의 츄잉정까지 판매되고 있다. 그러나, 시판되고 있는 정제등은 붕해되어 용출되는데 오랜시간이 소요되어 대한약전에는 약 30분간에 80%이상의 용출기준이 설정되어 있으며, 독특한 쓴맛 때문에 microencapsulation 한 제피세립을 사용하고 있으나 역시 1 정당 300mg 이상의 확산정이나 속용정은 존재하지 않는다. 이것을 개선하기 위하여 붕해속도가 빠르고 특히 진통효과가 빠르며 물없이 구강내에서 간편히 녹여 복용하거나 또는 씹어서 또는 물과 함께 복용할 수 도 있는 $\ulcorner$알카펜$\lrcorner$ 속용정을 개발하게 되었다 (그림2).

• Proceedings of the Korean Institute of Building Construction Conference
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• 2016.10a
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• pp.22-23
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• 2016

This study analyzes the properties of foam according to the concentration of vegetable foaming agent that is used in traditional and mixed foaming agent of developing stage, and confirms how the foams influence foamed concrete by searching for properties of foamed concrete according to replacing ratio of vegetable foaming agent and mixed foaming agent. This is for the purpose of providing basic data for the use of foamed concrete through improvement on the problem such as unstability, falling in fluidity and the strength of existed foaming agent.

• Applied Chemistry for Engineering
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• v.8 no.2
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• pp.197-203
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• 1997

The effect of additives on the mechanical properties of polyurethane foam were investigated. The resin used in this study was prepared by adding catalyst, surfactant and cross-linker to both KONIX FA-703 polyether polyol(80%) and KONIX FA-733 polyether polyol(20%). The polyurethane was foamed by adding equivalent amount of isocyanate(TDI-80, prepolymer M-200, pure MDI) to the resin and was used in property measurements after 72 hours hardening. The physical properties of polyurethane foam were investigated in terms of density, tensile strength, tear strength, elongation, sound absorption coefficient and gel profile measurements. The effects of surfactant on the cell size was investigated by scanning electron microscopy(SEM). The sound absorption coefficient was directly related to the cell size. The physical properties were improved with increasing amount of surfactant(L-5309) until 1.0 part per hundred polyol(1.0pphp).

• Applied Chemistry for Engineering
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• v.30 no.5
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• pp.597-605
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• 2019

In order to improve the adhesion of water-based adhesive, gemini type nonionic reactive surfactants were synthesized and applied to water-based adhesives. The surfactants were synthesized by using maleic acid and polyoxyethylene cetyl ether having different length of ethylene oxide and confirmed by FT-IR and $^1H-NMR$. Their appearance was light yellow wax. The cloud point of the compound was more than $78^{\circ}C$. The measured critical micelle concentration (c.m.c) was $1.0{\times}10^{-4}{\sim}7.0{\times}10^{-4}mol/L$ and surface tension at c.m.c was 25.9~32.0 mN/m. As the number of ethylene oxide increased, the emulsifying power was improved. The foaming height of each compound by Ross-Miles method was 1.4~4.5 cm. The synthesized surfactants was then used as an emulsifier in emulsion polymerization of water-based adhesives and its physical properties were evaluated. The solid contents of prepared adhesives was 59%. The average particle size and initial tackiness of the prepared adhesives were 164~297 nm and ball no. of 20~32, respectively. The peel strength was $1.8{\sim}2.1kg_f/mm$. The retention rate of adhesives viscosity was evaluated to 99% during 30 days. Therefore, synthesized gemini type nonionic reactive surfactants are expected to be applied as an emulsifier for the high adhesive force.

• Journal of the Korean Wood Science and Technology
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• v.27 no.1
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• pp.79-87
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• 1999

To use the agricultural residues as the raw material of molded packaging material, the packaging trays were manufactured from rice-straw pulp. The physical properties were measured to compare non-treated trays with the addition trays, such as the addition of starch, rosin size, carboxymethyl cellulose(CMC), polyethylene glycol(PEG), alkylketene dimer(AKD), polyacryl amide(PAM). The results were as follows : 1. In the addition of starch, air permeability at addition of 5% was highest. Bursting strength and tensile strength were smaller than non-treated trays. 2. In the addition of rosin size, air permeability, bursting strength and tensile strength were smaller than non-treated trays. 3. In the addition of CMC, air permeability was higher than non-treated trays. Bursting strength and tensile strength were similar to non-treated trays. 4. In the addition of PEG, air permeability was higher than non-treated trays. Bursting strength at addition of 3% was the highest and tensile strength was smaller than non-treated trays. 5. In the addition of AKD, air permeability at addition of 1% and 5% was higher than non-treated trays. Bursting strength and tensile strength were smaller than non-treated trays. 6. In the addition of PAM, air permeability at addition of 0.01% was the highest. Tensile strength at addition of 0.01% were higher than non-treated trays. 7. The water absorption of the trays decreased with increasing adding of natural additives.

• Fire Science and Engineering
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• v.10 no.3
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• pp.29-40
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• 1996

The AFFF(Aqueous Film Forming Foam : 3M Company's Light Water) agent are synthetic compounds that foams which are similar to those produced by protein based materials. The foam extinguishing agent was used In the extinguisher was the AFFF agent. We sought, however, to make other foams by using halon 1301 (CF$_3$Br) and halon alternatives, such as HCFC Blend A($CHCIF_2$ 82%, $CF_3$CHCIF 9.5%m $C_{10}$$H_{16}$ 3.75%), HFC-227ea ($CF_3$ $CHFCF_3$) We selected these alternatives instead of air in order to raise the expansion ratio of the AFFF agent. By these means we discovered that it is possible to increase the expansion ratio of the AFFF agent up to 44:1 and up to 24:1 when HFC-227ea was used as a halon alternatives. Therefore our new foam extinguishing agents can be used in a portable extinguish agents can be used in a portable extinguishers.

• Magazine of the Korea Concrete Institute
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• v.9 no.1
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• pp.165-172
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• 1997

Lightweight foamed concrete is a concrete which is lighter than conventional concree by mixing ptetoamed foam in cement slurry. The objectives of this study are to develop optimal prefoarneti lightweight foamed concrete with high lightness. high flowability and enough strength fol special use of structural application by using the polymer foam agent. By mixing the admixtures such as silica-fume and fly-ash and the industrial by-product such as styrofoam for the purpose of practical use of industrial waste, lightweight foamed concrete shich has better lightness. flowability and strength than the conventional prefoamed lightweight foamed concrete is developed. This paper presents extensive data on characteristics of compressive strength and flowability of the concrete manufactured with the different factors in mix design and also presents optimum mix proportion.