• 한국해양환경ㆍ에너지학회지
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• 제19권4호
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• pp.274-285
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• 2016

동해중부연안(후포~거진)에서 해수 중 해양환경특성의 시공간적 분포양상을 살펴보기 위해서 2013~2014년에 계절별로 현장조사를 실시하였다. 표층 수온과 염분은 하계에 고온 저염, 동계에 저온 고염의 분포 양상이 뚜렷하게 나타났다. 저층 수온은 약 $2{\sim}7^{\circ}C$ 범위로 겨울에 상대적으로 높았으며, 염분은 약 34로 계절별로 큰 차이를 보이지 않았다. 표층수중 용존산소 농도는 약 $7{\sim}12mg\;L^{-1}$의 범위로 다른 계절에 비해 5월(평균: $11.4{\pm}0.3mg\;L^{-1}$)에 상대적으로 높았다. 표층수에서 수온과 용존산소 농도는 가을과 겨울에 유의한 음의 상관관계를 보여 이 시기에 수온이 용존산소량을 조절하는 주요인자인 것으로 판단된다. 표층수 중 용존무기질소와 용존무기규소는 여름에 비해 겨울에 각각 약 11배, 7배 높았다. 표층수 중 DIN:DIP 비는 약 16이었으나 봄인 5월에 상대적으로 낮은 값을 보였다. 반면 여름에는 상대적으로 높은 비를 보여 봄에는 질소, 여름에는 인이 식물플랑크톤의 성장에 제한인자로서 작용했을 것으로 판단된다. 해수 수질은 조사기간동안 I(매우좋음)~III(보통) 등급 수준이었으며, 상대적으로 낮은 저층 용존산소 포화도를 보인 가을에 일부 정점에서 IV 등급 수준으로 나타났다.

• 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.

• 한국염색가공학회지
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• 제9권2호
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• pp.1-9
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• 1997

This paper was carried out to introduce flame retardant and antibiotic properties to polyester(PET) and polyester/cotton(P/C) blend fabrics. PET and P/C blend fabrics were treated by a paddry-cure method in the aqueous solutions of the finishing agents(JA 6034, JA 6050, DC-5700). The corona discharge technique was applied to increase the polar group of the polymer surface. The characteristics of the treated fabric were investigated by means of scanning electron microscope (SEM) and electron spectroscopy for chemical analysis(ESCA), and water penetration time, limiting Oxygen index(LOI), and K/S value were also measured. Wettability of the fabrics was increased considerably with the corona discharge treatment. ESCA was used to elucidate the surface chemical composition of the fabrics treated with the corona discharge. Relative Ols intensity increased and oxygen was incorporated in the form of -C-O-, -C=O, and O=C-O on the polymer surface. The current study indicated that corona discharge treatment was effective for modifying the polymer surface.

• Elastomers and Composites
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• 제27권1호
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• pp.13-19
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• 1992

In this work, properties of ABS/AES blends were investigated. Blends were prepared by casting from THF. The thermal stability, light resistance, storage modulus and flame retardancy were measured by thermogravimetric analysis, cole. difference in Fade-o-meter, Rheovibron, and limiting oxygen index(LOI). The thermal stability, light resistance and storage modulus increased with increasing contents of AES. ABS and AES showed similar LOI. The LOI of the ABS/AES blends increased with rising contents of AES but all the blends were found to be flammable. It was observed that ABS and AES was incompatible from the morphology by scanning electron microscope(SEM).

• 한국화재소방학회:학술대회논문집
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• 한국화재소방학회 2008년도 춘계학술논문발표회 논문집
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• pp.168-172
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• 2008

The flame retardancy by the addition of clay was evaluated to present as the fundamental data to decrease the fire hazard of polymers and life losses. The flame retardancy was examined to increase flame retardancy and to decrease smoke yield of epoxy by the addition of clay such as montmorillonite. For this study, the experiments of flame retardancy were conducted as follows : the measurement of the limiting oxygen index(LOI), char yield, and smoke density. As MMT concentration increased, epoxy/MMT composite increased LOI and char yield with the decreased smoke density.

• 한국안전학회지
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• 제21권1호
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• pp.79-85
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• 2006

Olefinic compatibilized blend(R-PP/R-PE)/layered silicate composites have been prepared by melt intercalation technique directed from $Na^{+}$ montmorillonite(MMT) or organophilic montmorillonites while using magnesium hydroxide as flame retardant. Morphology and flammability properties were characterized by X-ray diffraction(XRD), transmission electron microscopy(TEM), scanning electron microscopy(SEM), thermogravimetry analysis(TGA), limiting oxygen index(LOI), UL94 test. It is found that the compatibilized blend/layered silicate(Cloisite 20A) nanocomposites have a mixed immiscible-intercalated structure and there is better intercalation when a compatibilizer is combined with the polymer and layered silicate to be melt blended. A very large increase in the LOI value was observed with hybrid filler addition and further enhancement in thermal stability and compatibility of blend was obtained for the compatibilized blend containing small amount of layered silicate.

• Macromolecular Research
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• 제16권7호
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• pp.620-625
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• 2008

A novel nitrogen-phosphorus compound, diphenyl piperazine-1,4-diylbis(methylphosphinate)(DPPMP) was synthesized via a two step reaction and its flame retarding efficiency as a single component additive was investigated. The success of synthesis was confirmed by FTIR and $^1H$ and $^{31}P$ NMR analysis. The product was mixed with polycarbonate (PC), poly(butylene terephtalate) (PBT), ethylene-vinyl-acetate copolymer (EVA), and acrylonitrile-butadiene-styrene copolymer (ABS). The flame-retarding efficiency was evaluated using the limiting oxygen index (LOI) and the UL-94 vertical test methods. The addition of DPPMP enhanced the flame retardancy of the polymers and the V-0 ratings were obtained for the polymers examined in this study at a loading of 7-30 wt%. The gas-phase flame retardancy mode of action was suggested for this material from the thermogrametry experiment results.

• 한국안전학회지
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• 제19권1호
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• pp.77-80
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• 2004

The purpose of this study was to examine effects of combustion retardation for paper filter impregnated metal salts by measurement of extinguishing concentration, CO concentration, and limiting oxygen index(LOI, ASTM D 2863). And thermal stability analysis using DSC was carried out. In case of extinguishing concentration, $NH_4H_2PO_4$ showed excellent effect of combustion retardation. The result of LOI measurement showed that metal salts possessed good effect of combustion retardation. And thermal analysis using DSC showed that these metal salts possessed thermal stability. In case of CO concentration, CO concentration was increasing because of imperfect combustion process due to combustion retardation effect of metal salts.

• Advances in materials Research
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• 제9권4호
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• pp.311-321
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• 2020

In this study, Mangifera Indica tree sawdust reinforced bisphenol-A aniline based benzoxazine composites were prepared by varying the sawdust from 20 wt% to 45 wt%. Thermogravimetric analysis of composites revealed excellent compatibility between polybenzoxazine and sawdust from the remarkable growth in char yield from 22% (neat resin) to 36% (for highly filled) and glass transition temperature from 151 to 165℃. Ultimate weight loss of the composites evaluated from the Derivatives of TG plots. Limiting oxygen index values of the composites reported considerable growth i.e.,from 28 to 32 along with the increase in filler content. Differential scanning calorimetry results showed that sawdust particles have an insignificant effect on curing temperature (219℃) for the raise in sawdust content. Structure of the sawdust, benzoxazine monomer, polybenzoxazine and composites were studied using Fourier transformation infrared spectroscopy. Overall, polybenzoxazine composites with sawdust as filler showed improved thermal properties when compared with pure polybenzoxazine.

• 폴리머
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• 제39권3호
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• pp.433-440
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• 2015

에틸렌비닐아세테이트(EVA)에 난연성을 부여하기 위해서 일반적으로 무기 난연충전제인 수산화알루미늄(ATH)이 사용되고 있다. 본 연구에서는 폐포장재 다층 필름의 재활용 공정에서 부생하는 ATH를 사용하여 EVA에 대한 난연제로서의 특성을 조사하였다. EVA/ATH 복합재료를 two roll-mill을 이용하여 제조하고, 이 복합재료의 난연성 및 물리적 특성을 조사하였다. 난연성은 한계산소지수(LOI) 및 UL-94 평가를 이용하여 확인하였다. EVA 수지에 재활용된 ATH가 150 phr 이상 첨가되었을 때 우수한 난연 특성을 나타내었다. ATH의 입자 크기 및 비표면적이 EVA/ATH 복합재료의 LOI 값 및 UL-94 평가의 등급에 영향을 주는 인자임을 확인하였다. 즉 ATH 입자 크기가 작을수록, 비표면적이 클수록 난연성은 증가되는 것으로 나타났다. 기계적 물성의 경우 실제로 전선 등에 이용되고 있는 가교형 EVA/ATH 복합재료의 경우 재활용된 ATH를 첨가하여도 인장물성은 저하되지 않고 첨가하지 않은 경우와 유사하거나 오히려 우수한 것으로 나타났다.