• 공업화학
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• 제25권4호
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• pp.418-424
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• 2014

본 연구에서는 NaCl/$H_3PO_4$ 혼합수용액을 사용하여 라이오셀 섬유의 내염화 처리를 수행하고 이에 따른 열 안정성과 내산화성의 향상 효과를 고찰하였다. 라이오셀 섬유를 다양한 공정조건으로 내염화 처리한 후 열 안정성과 내산화성을 측정 및 분석하고 그에 따른 메커니즘을 제시하였다. 실험결과, 내염화 처리된 라이오셀 섬유의 적분 열분해 온도(integral procedural decomposition temperature, IPDT)와 한계산소지수(limited oxygen index, LOI)는 약 23, 30% 증가하였으며, 활성화 에너지(activation energy, $E_a$) 값은 약 24% 향상된 것을 알 수 있었다. 이러한 결과는 $H_3PO_4$와 NaCl가 연소시 에스테르화 반응, 탈수소화 반응 및 C-C결합의 분해반응으로 char 형성을 촉진하고 섬유 표면에 형성된 탄소 층을 형성함으로써, 고분자 수지 내부로 산소와 열 공급을 물리적으로 차단하여 열 안정성과 내산화성이 향상된 것으로 판단된다. 이러한 결과를 바탕으로, NaCl/$H_3PO_4$ 혼합수용액을 이용한 내염화 처리 공정의 최적화된 인자 및 메커니즘을 제시하였고 열 안정성과 내산화성이 향상된 라이오셀을 성공적으로 제조하였다.

• 한국염색가공학회지
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• 제9권3호
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• pp.1-9
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• 1997

Plasma techniques permit modification of the surface layers of the substrate while maintaining its bulk properties. The use of plasma treatment on textile fibers and fabrics is very limited, however, the limitations, plasma treatments have been used to modify surface properties of textiles. In this study, multifunctional finish was performed by corona discharge technique for surface functionalization. Electron spectroscopy for chemical analysis(ESCA) was used to determine the ratios of carbon, oxygen, nitrogen, and phosphor at a 20$\AA$ sampling depth. K/S value and limiting oxygen index(LOI) value were used to obtain information on the effect of the finished fabrics. The mechanism of the flame retardancy was analyzed by the thermogravimetry-and the residue number. In ESCA, relative N1s intensity increased in case of mixtrure. The flame retardancy of the polyester and polyester/cotton fabrics treated with JA-6034 and JA-6050 was found to be operative mainly in the condensed phase mechanism. The multifunctional finish was better effect for the post treated finish agent.

• Ocean and Polar Research
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• 제27권1호
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• pp.45-58
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• 2005

Temperature, salinity, dissolved oxygen, COD, dissolved inorganic nitrogen(DIN), dissolved inorganic phosphorus (DIP), and chlorophyll were measured in the surface and bottom waters of Cheonsu Bay in April, August, December 2003, and Hay 2004. DIN showed a large seasonal variation, with higher values in summer and lower in spring. The significant decrease in DIN concentration was observed from April to May, which may imply the occurrence of spring phytoplankton bloom sometime in these periods. In contrast, DIP did not show distinct seasonal variation, with relatively low values compared with other coastal regions. The low DIP concentration in Cheonsu Bay is ascribed to a limited phosphorus input around Cheonsu Bay. The Nf ratios of Cheonsu Bay much higher than the Redfield ratio(16) in all season indicate that phytoplankton growth is limited by phosphorus. Based on low chlorophyll concentrations and eutrophication index, Cheonsu Bay has not been in eutrophic condition during our observation periods. In the artificial lakes located around Cheonsu Bay, however, chlorophyll concentrations were very high, mostly over $10{\mu}g\;l^{-1}$, indicating that they are now in severe eutrophic condition.

• 한국안전학회지
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• 제25권3호
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• pp.45-52
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• 2010

The purpose of this study is application to flame retardant powder coating(FRPC) material consisting of ammonium polyphosphate(APP) and magnesium hydroxide($Mg(OH)_2$) as a halogen free flame retardant into thermoplastic resin(LDPE-g-MAH). For improvement of adhesion, LDPE-g-MAH was synthesized from low density polyethylene(LDPE) and maleic anhydride(MAH). The mechanical properties as melt flow index, pencil hardness, cross-hatch adhesion and impact resistance of FRPC were measured. Also, the limited oxygen index(LOI) values were measured 17.3vol%, 31.1vol% and 33.7vol% for LDPE-g-MAH, FRPC-3(APP 15wt%, $Mg(OH)_2$ 15wt%) and FRPC-5(APP 30 wt%), respectively. The thermo gravimetry/differential thermal analysis(TG/DTA) of FPRC-3 was observed endothermic peak at $340^{\circ}C$ and $450^{\circ}C$, it was confirmed predominant thermal stability though the wide temperature range by APP and $Mg(OH)_2$. It was showed V-0 grade for FRPC-3 and FRPC-4(APP 20wt%, $Mg(OH)_2$ 10wt%) that a char formation and drip suppressing effect, and combustion time reduced by UL94(vertical burning test). It was confirmed that flame retardancy was improved with the synergy effect because of char formation by APP and $Mg(OH)_2$.

• 한국염색가공학회지
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• 제20권4호
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• pp.8-14
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• 2008

Flame-retardant cotton fabrics were prepared by UV curing of photocurable aqueous formulations of phosphorous-containing methacrylate monomers and 2-hydroxy-2-methyl-1-phenyl-1-propanone as flame retardants and a photoinitiator respectively, which is an environmentally friendly and energy-saving process. The characterization of the UV-coated cotton fabric was made by ATR, TGA and limited oxygen index measurement. UV cured coating onto cotton fabrics reduced the first thermal decomposition temperature and mass loss as well as increase in the amount of char residue compared with the untreated cotton fabric presumably due to modified thermal decomposition process. The LOI values up to 28.5 and 27.2 were obtained by the UV curing of MMEP and TMEP respectively. The treatment was durable to five laundering cycles, which was more prominent in the case of trifunctional TMEP treatment.

• 대한가정학회지
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• 제25권1호
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• pp.43-50
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• 1987

Non-durable flame retardant finish, borax/boric acid mixed solution, was applied to cotton fabric with pad-dry method. The LOI(limited oxygen index) was measured as the measare of the flame retardant effect. The TGA was investigated to know the thermal behavior of the samples. In addition, the solubility of the solutions was investigated. The results were as follows: 1) There was a synergism of flame retardant effect in the borax/boric acid mixed solution treatment and the maximum synergism was shown around the ratio of 7 : 3 2) After the borax/boric acid solution treatment, the degradation temperature was lowered and degraded at the larger temp range with slower rate. The residual char length also increased. 3) The solubility of borax/boric acid become higher when the ratio of borax/boric acid became similar. Compositions from 80/20 to 40/60 borax/boric acid mixtures were solubilized well in room temperatuare or warmwater therefor there was no problem for home use.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(III)
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• pp.327-332
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• 2003

We investigated the fire characteristics of the subway electric car's interior materials and evaluated the safety of it. The testing methods are ISO 4589-2 for Limited Oxygen Index, ISO 5658-2 for surface flame spread, ISO 5660-1 for Heat Release Rate, ASTM E 662 for smoke density and BS 6852 Annex B.2 for gas toxicity. The materials of seven organization including KNR were tested. Most of the materials are under the levels of the foreign country's demand. We also reported the test methods of other countries and compared it to ours.

• 한국방재학회 논문집
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• 제10권3호
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• pp.77-83
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• 2010

본 연구에서는 건축물 내장재 가운데 바닥재의 화재특성을 평가하기 위하여 목재, 모노륨, 장판지, 니스코팅 된 장판지 등 4종의 바닥재를 대상으로 콘칼로리미터, 발화온도시험기, 열중량분석기, 한계산소지수시험기 등을 이용하여 착화성, 발열특성, 난연성과 같은 연소특성을 분석하였다. 모노륨은 발화온도가 $325^{\circ}C$로 가장 낮았으며, 장판지와 니스코팅 된 장판지는 비교적 빠른 시간인 7초 이전에 착화가 시작되었다. 총열방출량은 목재가 $100MJ/m^2$로 가장 높게 나타났지만 최대열방출율은 니스코팅된 장판지가 가장 높은 것으로 나타났다. 열중량분석 결과, 모든 바닥재들이 $300{\sim}400^{\circ}C$ 온도구간에서 급격한 중량감소를 보였으며, 한계산소지수는 장판지와 니스코팅 된 장판지가 20~21% 정도이고 목재는 34%로 나타났다. 본 연구결과를 살펴보면, 모노륨, 장판지, 니스코팅 된 장판지는 착화가 빠르고 연소가 용이한 반면, 발열량은 낮은 것을 알 수 있었으며, 목재는 비교적 착화위험성이 낮고 난연성은 좋지만 발열량이 높은 것으로 나타났다.

• 한국염색가공학회지
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• 제32권2호
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• pp.103-110
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• 2020

Super engineering plastic(SEP) are applied to high performance and high value industries due to their excellent mechanical properties and high continuous operating temperature. Among them, PES and PEI are amorphous SEPs, and have the advantages of high flexibility, mechanical properties, transparency, and thermal stability. In this study, polyethersulfone(PES) and polyetherimide(PEI) fibers were manufactured to produce flame retardant artificial hair. PES and PEI fibers prepared through a melt-spinning process at a high temperature of 360 to 420℃. They are compared with commercial artificial hair by thermal gravimetric analysis(TGA), linear density, tenacity, and limited oxygen index(LOI) analysis. PES and PEI fibers have similar linear density and tenacity to commercial artificial hair, while their thermal stability and flame retardant are excellent. In particular, flame retardant was analyzed through LOI value and PES was 35.1%, which is superior to commercial artificial hair PET/Br(28.2%) and PET/P(20.2%). Therefore, PES and PEI are suitable as artificial hair for flame retardant.

• 한국화재소방학회논문지
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• 제21권1호
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• pp.74-81
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• 2007

본 연구는 다중이용업소에서 사용하고 있는 실내장식재들 가운데 카페트와 커튼을 대상으로 방염 처리 여부와 방염 처리한 카페트의 사용 여부에 따라 화재의 위험 요소인 열방출율, 연기밀도, 발화점 그리고 난연성을 평가하였다. 방염 처리 여부에 따른 실험 결과를 살펴보면, 방염 처리한 재료가 방염 처리를 하지 않은 재료보다 발열량이 낮게 나타났지만 연기밀도 지수는 오히려 높은 것으로 나타났다. 또한, 방염처리한 카페트의 사용 여부에 따른 실험결과로는 3년 사용한 중고카페트가 사용하지 않은 새 카페트보다 발열량과 연기밀도 지수가 높게 나타났으며, 동일 재료일지라도 사용여부에 따라 난연성과 발화온도의 차이가 있는 것으로 나타났다.