• Journal of the Korean Applied Science and Technology
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• 제16권2호
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• pp.179-185
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• 1999

The effect of blowing agents and inner temperature on the machanical properties of the flexible polyurethane foams were investigated. In the study used that chemical blowing agents is $H_2O$ and support blowing agents. CFC-11, HCFC-114b, dichloromethane, n-penthane, iso-pentane, cyclopentane. The flexible polyurethane foams were foamed by the density of $0.015{\pm}0.002g/cm^3$ and $0.024{\pm}0.002g/cm^3$ which were used in mechanical properties measurements. Inner temperature was measure as long as the preparation of the flexible polyurethane foams of each blowing agents. The density, tensile strength, elongation, tear strength, compression strength and compression set were measured after 48 hours hardening. The result of the study was optimized dichloromethane and cyclopentane at the support blowing agents.

• Journal of the Korean Institute of Gas
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• 제20권2호
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• pp.30-34
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• 2016

In this study, we synthesized a phenol foam using a resol-type phenol resin as a research for replacing the polyurethane foam used as an insulator for cryogenic temperature, such as LNG or LPG. Foaming agents for synthesizing a phenolic foam was used HCFC-141b or n-pentane, cyclopentane, n-hexane, cyclohexane and a mixture of HFC-365mfc and HFC-227ea respectively. Cyclohexane as a blowing agent exhibited the most superior insulating performance and compressive strength. The heat resistance of polyurethane foam and phenolic foam blown by the cyclohexane, was higher than polyurethane foam.

• Journal of the Korean Geosynthetics Society
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• 제16권2호
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• pp.131-138
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• 2017

In this study, the expansion and compressive strength tests of emergency restoration material were carried out to restore cavity causing ground subsidence. The expansion and compressive strength characteristics according to component ratio of main material - hardener and mix proportion of blowing agent - accelerator were analyzed based on the test results. As a result of the relationship of curing time - expansion ratio analyses, it confirmed that expansion ratio decreased with reduced curing time regardless of mix proportion of blowing agent - accelerator in main material, if component ratio of hardener increased. This means that component ratio of the main material - hardener had greatly affected the expansion ratio. The compressive strength characteristics of emergency restoration material confirmed that strength was affected by mix proportion of blowing agent - accelerator. Therefore, it is necessary to apply reasonable component ratio and mix proportion to consider the required injection time, expansion ratio and strength of restoration material, when emergency restoration in ground cavity is required.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 한국정밀공학회 2004년도 춘계학술대회 논문요약집
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• pp.101-101
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• 2004

초미세 발포 플라스틱(MCPs; Microcellular Plastics)공정은 기존 발포 플라스틱의 장점을 보존하면서도 그 동안 발포 플라스틱의 단점으로 지적되어온 충격강도, 인성, 경도 등의 기계적 특성저하를 개선하기 위하여 개발되었다. 플라스틱 내에 지름 수 십 $\mu\textrm{m}$ 내외의 기포를 $10^{9}$-$10^{15}$cel1/㎤의 밀도로 발생시키는 초미세 발포공법은 내부의 미세 구조로 인하여 재료비를 절약하면서 우수한 기계적 특성을 나타내는 플라스틱 재료를 성형할 수 있게 하며, 발포제로 초 임계 상태의 불활성 기체($CO_2$, $N_2$, etc)를 사용하기 때문에 기존의 발포 공정에서 발포제로 사용했던 유해 화학 물이나 프레온, 부탄으로 인해 발생할 수 있는 환경 문제를 해결할 수 있다는 장점을 지닌다.(중략)

• Proceedings of the Korean Society of Disaster Information Conference
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• 한국재난정보학회 2017년 정기학술대회
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• pp.241-242
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• 2017

본 논문에서는 폐유리를 재활용하는 발포유리에 대한 기술 및 활용방법에 대한 고찰을 통해 국내에서 적용 가능한 폐유리 재활용기술에 대하여 검토하였다. 폐유리를 재활용한 발포유리는 폐유리를 분쇄한 유리 미분에 규산나트륨, 탄산칼슘, 그라파이트 등의 발포제를 첨가하여 형틀에 넣고 가열을 하면, 유리분말은 소결(sinter)상태가 되는 약 $800^{\circ}C$ 정도가 되면 녹기 시작하고, 발포제는 분해되어 $O_2$와의 반응에서 발생하는 $CO_2$ 가스에 의한 기포가 발생하여 발포유리가 형성되는 제조 방식이다. 이러한 발포유리 방식으로 제작된 판재 및 배관 형태의 불연재료는 건설 및 LGN선박용으로 널리 활용되고 있고, 인공경량 골재의 형태는 건설용 채움재 및 빗물 저류용, 정화용으로 활용되고 있다. 이러한 활용 방식은 국내에서도 충분히 적용 가능한 방식이며, 국내에서의 적용을 통해 폐기물 및 환경부하 저감 효과를 높일 수 있다.

• Applied Chemistry for Engineering
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• 제23권1호
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• pp.77-85
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• 2012

Production process of the flexible ceramic foamed body through the complexation with the fiberous sepiolite and expanded pearlite was researched. The processing of fibrillation of the inorganic mineral fiber sepiolite is the most important whole processing for manufacturing of the ceramic foamed body consisting of the expanded perlite and sepiolite. The fibrous sepiolite and expanded pearlite are blended and becomes the slurry phase. And this slurry phase is converted to a massive foamed body through the low temperature heat treatment process less than $300^{\circ}C$. The heat-treatment process of the slurry phase composite has to be designed to include the evaporation step of the moisture remaining among the slurry composition, foaming step by the decomposition of the foaming agent, and resolution removal step of the organic material which was added in the composite remained after the foaming step. The heat treatment process should be considered as significant factors in design of total process. As to the condition of heat treatment process and foaming agent, there was the a correlation. An organic type foaming agent like DSS (dioctyl sodium sulfosuccinte) was effective in foaming of the slurry compound consisting of the expanded perlite and sepiolite fiber.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제12권1호
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• pp.56-61
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• 2002

Porous clay ceramics was fabricated using the surfactant as a foaming agent in the secondary-clay produced at Young-Am area in Chun-Nam province. The concentration of surfactant in ceramic slurry was the key factor controlling the pore characteristics and physical properties of the porous ceramics. The more increase of the surfactant concentration increase the more foaming ability and the stability of foamed layer were improved, but the foaming ability was limited within 6.0 wt% of surfactant because the initial viscosity of the slurry increased with increasing the amounts of surfactant. The formed specimen were sintered at both $1150^{\circ}C$ and $1200^{\circ}C$, the porous ceramics showed 0.9 of specific gravity, 50% of water absorption, 45% of apparent porosity, 14% of shrinkage and 70 kg/$\textrm{cm}^2$ of compressive strength.

• Journal of the Korean Crystal Growth and Crystal Technology
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• 제19권1호
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• pp.48-53
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• 2009

The effect of bloating and fluxing agent on the microstructure and physical properties were studied in manufacturing the artificial lightweight aggregates of bulk density below] using clay and stone sludge. In case of the aggregates added only with bloating agent, the bulk density and water absorption were $0.5{\sim}1.0$ and $41{\sim}110%$ respectively but the microstucture was not uniform with a rough appearance. For the aggregates added with a fluxing agent and one bloating agent, a part of shell was lost due to explosion of specimen caused by over-bloating during a sintering. The mixed addition of bloating agents with vacuum oil, carbon and ${Fe_2}{O_3}$ made the microstructure homogeneous by generating an uniform black core and shell structure. The aggregates added with mixed agents and sintered at $1200^{\circ}C$ showed the bulk density 67 % lower and water absorption 48 times higher than those of the specimen with no additives. ]n this study, the artificial lightweight aggregates showing the bulk density of $0.5{\sim}1.0$ and water absorption of $50{\sim}125%$ could be fabricated to apply to various fields.

• Journal of the Korean Institute of Gas
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• 제8권2호
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• pp.1-7
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• 2004

The physical properties of rigid polyurethane foam(PUF) synthesized using various types of blowing agents such as water, HFC-365mfc, HFC-245fa, HCFC-l4lb, CFC-11 and n-pentane were studied. The blending effect of blowing agents were also studied. The thermal conductivity, reaction rate, and cell morphology of the PUF with various blending ratio of blowing agents were investigated. The PUF blown by water shows the highest compressive strength among other single blowing agents. The thermal conductivity of PUFs blown by HFC-245fa and HFC-365mfc are close to that of PUFs blown by CFC-11. When HFC-365mfc was mixed with HFC-245fa(30mo1e$\%$) as coblowing agent, the mechanical property shows the highest value among other coblowing agents. It is that the thermal conductivity of PUFs depends on cell size of PUFs as well as thermal conductivity of blowing agent in gaseous form.

• Journal of the Korean Institute of Gas
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• 제9권1호
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• pp.16-20
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• 2005

CFC-11 and HCFC-l4lb have been used as blowing agents for rigid polyurethane foam insulation of LNG storage tank. But CFC-11 and HCFC- l4lb deplete ozone layer in the stratosphere. So in leading countries, the use of CFC-11 has been prohibited since 1995 and the use of HCFC-l4lb will be prohibited from 2005. Much efforts and studies have been done about alternative blowing agents and insulations blown by alternative blowing agents. This paper deals with polyurethane foams (PUFs) blown by HFC-365mfc, shows their physical and mechanical characteristics and thermal performance. These data are compared with the results of PUFs blown by HCFC-l4lb. From these test results, PUFs blown by HFC-365mfc show good mechanical and thermal characteristics. It is possible to use PUFs blown by HFC-365mfc as main insulation of membrane type LNG storage tank.