• Proceedings of the Korea Air Pollution Research Association Conference
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• 2001.11a
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• pp.331-332
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• 2001

CFCs는 가정 제품과 공업적 과정에서 발포제와 냉매제로 오랜 기간 사용되었다. 1974년, CFCs는 Molina와 Rowland에 의해 성층권 오존의 고갈 요인으로 인식되었고, 최근에는 지구 온난화의 기여물질로써 관련되어 지고 있다. CFCs의 세계적인 생산은 Montreal 의정서와 그 개정안에 의해 점차 폐지되었고, 대체 물질로 HCFCs와 HFCs가 과도하게 사용되고 있다. 수소의 존재는 대체 물질의 대류권 산화를 가능하게 했고, 대체로 성층권에 영향을 미치지 않는다. (중략)

• Journal of the Korean Institute of Gas
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• v.20 no.2
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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 Institute of Gas
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• v.9 no.1 s.26
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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.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.247-248
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• 2002

CFCs는 가정제품과 공업의 생산과정에서 발포제와 냉매제로 오랜 기간 사용되었다. 1974년, CFCs는 Molina와 Rowland에 의해서 성층권 오존의 고갈 요인으로 인식하게 되었고, 최근에는 지구 온난화의 기여물질로써 사회적 관심이 증가하였다. CFCs의 세계적인 생산은 Montreal 의정서와 그 개정안으로 인해 점차 감소하면서 사용이 폐지되었고, 대체 물질로 HCFCS와 HFCs가 사용되고 있다. 대류권에서 HCFCs와 HFCs는 hydroxyl radicals에 의해 산화되고, 최종 분해산물로 무기산, 염, HF, $CO_2$, HC와 Trifluoroacetic acid(TFA)가 생성된다. (중략)

• Elastomers and Composites
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• v.39 no.2
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• pp.105-120
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• 2004

The flame retarded NBR foams were prepared with metal hydroxides and various phosphorus/nitrogen-contain ing flame retardants. The dependency of the phosphorus content on thermal properties, flame retardancy, smoke density, and foaming properties were investigated in the foams. Foaming properties and morphology of the flame retarded NBR foams with P/N flame retardants( ${\le}10 phr$) were similar to those of the foams without P/N ones but containing metal hydroxides The flame retardancy of the foams was improved with increasing the phosphorus content and char formation under combustion atmosphere. The cone-calorimeter test and LOI index were also coincided with the TGA analysis quite well. The heat release rate (HRR), total heat release (THR), and effective heat of combustion (EHC) were decreased, whereas the carbon monoxide yield was increased with increase of the phosphorus content of P/N flame retardant. The smoke density values were closely related with CO yield values obtained by the cone-calorimeter test due to the high and hard char formation.

• Journal of the Korean Recycled Construction Resources Institute
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• v.2 no.2
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• pp.166-171
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• 2014

This experimental study considers manufacturing method of the non-portland cement matrix for the light-weight building materials using blast furnace slag, paper ash, fly ash and polysilicon sludge the industrial by-product. For the experiment, we used paper ash by means of the foaming agent and alkali activator to make non-portland cement light-weight matrix. Various specimens were prepared with different types and addition ratios of the alkali activator. Then, the properties of these specimens were investigated by compressive strength test, bulk specific gravity. As a results, it was judged that experiment results of non-portland cement matrix with specific waste resources and alkali activators were useful as basic data for mixtures design and evaluation properties of lightweight non-portland cement building material.

• Journal of the Korean Institute of Gas
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• v.5 no.4 s.16
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• pp.79-84
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• 2001

In this study, the effect of polyol structure(OH-value, functionality) on the reactivity, mechanical property and cell morphology of polyurethane foam and the possibility of replacing HFC-36smfc was examined by evaluating how each blowing agent(CFC-11, HCFC-l4lb, HFC-36smfc) affects the reactivity, mechanical property and cell morphology. Results of the experiment showed that as the functionality and OH-value of polyol increased, there was an increase in the temperature profile, reaction rate, density and compressive strength. However. as the functionality and OH-value increased. the ceil size became smaller The use of different kinds of blowing agents did not appear to have and significant influence on the temperature profile, reaction rate, density and compressive strength. The foam using HFC-365mfc produced more uniform cells compared to the foam using HCFC-l4lb.

• Polymer(Korea)
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• v.28 no.5
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• pp.412-425
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• 2004

The influence of expandable graphite (EG) on flame retardancy and foaming properties of the NBR/GTR foams was studied. The foaming properties were similar to those of NBR/GTR foams without EG when the EG contents were 10$\~$30 phr. The LOI values were increased with the EG content. For cone-calorimeter test, the data showed the trend similar to that from experiment. When the composition ratios of the compounds of NBR/GTR were 100$\~$0/80$\~$20 (w/w), and the EG contents were 10$\~$30 phr, we obtained high flame retardancy foams with low heat release rate (HRR), total heat release (THR), effective heat of combustion (EHC) and carbon monoxide yield (COY). The smoke density is similar to CO yield values obtained by the cone-calorimeter test. TGA analysis also showed the results approximately similar to those from the LOI and cone-calorimeter experiments.

• 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.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.1
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• pp.33-39
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• 2020

Lightweight geopolymers were fabricated by using fused slag from integrated gasification combined cycle as a law material and Si sludge from silicon wafer process as a bloating material for the purpose of replacing autoclaved lightweight concrete (ALC). Density and compressive strength of geopolymers were measured and compared with the properties of ALC according to the variation of mol concentration of alkaline activator, W/S ratio, addition of fibers, and addition of polystyrene and the possibility of replacing ALC panel was estimated through the comparisons. Although the geopolymer satisfying the standard of ALC panel was not made by controlling mol concentration and W/S ratio, addition of inserts such as fibers and polystyrene insert was tried to overcome the obstacle of enhancing properties. Geopolymers cannot satisfying the standard of ALC panel by adding carbon or glass fibers; however, adding fibers can be suggested as one of the methods enhancing compressive strength because the compressive strength of the specimen containing 0.3 wt.% glass fibers was increased by 3 times. The maximum addition of polystyrene insert was turned out to be 50 vol.% and the properties of geopolymers varied by the method of insertion. When using single polystyrene insert, compressive strength was 17.8 MPa and density was 0.996 g/㎤ which were similar values to the standard of ALC panel. If the difficulties of reproductivity of production and insertion method of inserts were overcome through the future research, the geopolymers containing polystyrene inserts could possibly replace ALC panel.