• Title/Summary/Keyword: LOI index

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Assessment on the Flame Retardancy for Polyethylene/Montmorillonite Nanocomposite (Polyethylene/Montmorillonite Nanocomposite의 난연성 평가)

  • Song, Young-Ho;Chung, Kook-Sam
    • Fire Science and Engineering
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    • v.20 no.4 s.64
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    • pp.72-76
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    • 2006
  • Polymer/clay nanocomposites have generated considerable interests in the past decade because adding just tiny amount of clay to the polymer matrix could produce a dramatic enhancement in physical, thermal and mechanical properties. Smectite clays, such as montmorillonite (MMT), are of great industrial value because of their high aspect ratio, plate morphology, intercalative capacity, natural abundance and low cost. In this study, PE/MMT nanocomposites were directly prepared by melt intercalating PE and the modified clay. The nanostructure was verified by X-ray diffraction (XRD) and transmission electron microscopy (TEM), and their flame retardant properties were measured and discussed by limiting oxygen index (LOI), char yield and smoke mass concentration. And their thermal stabilities were measured by differential thermogravimetric (DTG) and thermogravimetric analysis (TGA). The PE/MMT nanocomposites proved more effective the conventional composites in reinforcement. Two functions in the thermal stability of the PE/MMT nanocomposite, one is the barrier effect to improve the thermal stability, and another is catalysis, leading to a decrease of the thermal stability. The flammability was greatly decreased due to the formation of the clay-enriched protective char during the combustion.

Preparation of Flammability Artificial Hair based on Super Engineering Plastic (슈퍼엔지니어링 플라스틱 기반 난연성 가발사 제조)

  • Choi, Hyun-Jung;Gong, Da Jeong;Youn, Chulmin;Yeo, Sang Young
    • Textile Coloration and Finishing
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    • v.32 no.2
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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.

The Flame Retardant and Mechanical Properties of Wood Flour-High Density Polyethylene Composites (목분-HDPE 복합체의 난연성 및 기계적 성질)

  • Shin, Baeg-Woo;Bang, Dae-Suk;Song, Young-Ho;Chung, Kook-Sam
    • Journal of the Korean Society of Safety
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    • v.27 no.1
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    • pp.26-31
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    • 2012
  • Wood-plastic composites represents a growing class of materials used by the residential construction industry and furniture industry. In this study, the effect of flame retardants on the flammability and mechanical properties of wood flour-high density polyethylene(HDPE) composites were studied. we were manufactured wood flour-HDPE composites by modular intermeshing co-rotating twin screw extruder with L/D ratio of 42. The flame retardant properties were used limiting oxygen index(LOI) and mechanical properties were measured by universal testing machine(UTM). The Morphological analysis of composites were analyzed by Scanning electron microscope(SEM). It was found that Ammonium polyphosphate can effectively reduce the flammability of the wood flour-HDPE composites. Marginal reduction in the mechanical properties of the composites was found with addition of flame retardants. SEM images showed that the coupling agent improved wood flour-HDPE interfacial bonding.

Synthesis and Flame Retardant Improvement of PU Coatings Containing Trichloro Modified Polyester/IPDI-Isocyanurate

  • Kim, Ji-Hyun;Keun, Jang-Hyoun;Jung, Choong-Ho;Kim, Seung-Jin;Kim, Young-Geun;Kim, Seong-Kil;Park, Hong-Soo
    • Journal of the Korean Applied Science and Technology
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    • v.25 no.3
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    • pp.332-340
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    • 2008
  • Two component polyurethane (PU) flame retardant coatings were prepared by blending trichloro modified polyesters (TCMPs) and isophorone diisocyanate isocyanurate. TCMPs were synthesized by polycondensation of trichlorobenzoic acid (TCBA), a flame retardant component, with adipic acid, 1,4 butanediol, and trimethylolpropane. The content of TCBA was varied in 10, 20, and 30 wt% for the reaction. Theses new flame retardant coatings showed various properties comparable to other non flame retardant coatings. Moreover, we carried out the combustion test and the flammability test for our flame retardant coatings. The results of vertical burning test for the coatings containing more than 20 wt% of TCBA were determined as no burn. The results of flammability test for the coatings with 20 wt% and 30 wt% of TCBA contents indicated the limiting oxygen index (LOI) values of 26% and 29% respectively, which implied relatively good flame retardancy.

Influence of Fluoro-illite on Flame Retardant Property of Epoxy Complex (에폭시 복합체의 난연 특성에 미치는 불소화 일라이트의 영향)

  • Yu, Hye-Ryeon;Jeong, Eui-Gyung;Kim, Jin-Hoon;Lee, Young-Seak
    • Polymer(Korea)
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    • v.35 no.1
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    • pp.47-51
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    • 2011
  • In this study, illite, an environmental friendly, low cost, and high aspect ratio additive, was used to improve flame retardant property of epoxy and it was fluorinated to enhance dispersion of hydrophilic illite in hydrophobic epoxy by introducing hydrophobic functional groups. Fluorination of illite enhanced illite dispersion ill epoxy solution before curing and that in the complex after curing. These enhanced dispersions were attributed to the increased affinity of illite to hydrophobic epoxy solution induced by fluorination of illite and the increased intercalation of epoxy polymer or exfoliation of illite by epoxy curing. Hence, limited oxygen index(LOI) of fluorinated illite/epoxy complex increased by 24%, compared to that of epoxy, suggesting that the preparation of fluorinated illite/epoxy complex increased their flame retardant properties.

Fire Resistance Study of PP Thermoplastic Composites with Particulate Reinforcements and Br Flame Retardants (무기 입자 강화제와 브롬(Br) 난연제에 따른 폴리프로필렌 복합재료의 난연성 향상에 관한 연구)

  • 곽성복;황성덕;남재도;고재송;최형기
    • Polymer(Korea)
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    • v.26 no.2
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    • pp.260-269
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    • 2002
  • The fire resistance of particulate polypropylene composite systems were investigated by using various reinforced particles such as zeolite, talc, $CaCO_3$ particles. In this study, The effect of particle size on the thermal properties of composite and the effect of reinforced particles on the fire resistance were studied. The inorganic reinforced particles used in this study were recycled zeolite(average particle diameter=85.34 $mu extrm{m}$), $CaCO_3$ (33.93 $mu extrm{m}$), and talc (18.51 $mu extrm{m}$). The fire resistance of composite systems was thoroughly examined by measuring limited oxygen index (LOI, ASTM D2863) and cone calorimetry (ASTM E1354, ISO 5660). Thermal stability of composite systems was thoroughly examined by measuring TGA. The flame retardants (DBDPO) and reinforced particles reduce the maximum heat release rate (M-HRR) in the order of Talc > $CaCO_3$ > recycled Zeolite. Comparing the cone calorimetry experimental results of the particle reinforced polymer composite system exhibited twice higher efficiency than DBDPO in polypropylene systems, and the LOI also showed similar trends to the cone calorimetry experiments. The optical and scanning electron microscopy techniques were used to investigate the composites ash layer and the core fracture surfaces in the burning process. The reinforcing inorganic particles seemed to accumulate at the surface of ash layer, and subsequently intercept the oxygen transport and heat transfer into the core area.

A Study on Flammability and Mechanical Properties of HDPE/EPDM/Boron Carbide/Triphenyl Phosphate Blends with Compatibilizer (HDPE/EPDM/Boron Carbide/Triphenyl Phosphate 블렌드의 상용화제 첨가에 따른 난연성 및 기계적 물성 연구)

  • Shin, Bum-Sik;Jung, Seung-Tae;Jeun, Joon-Pyo;Kim, Hyun-Bin;Oh, Seung-Hwan;Kang, Phil-Hyun
    • Polymer(Korea)
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    • v.36 no.5
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    • pp.549-554
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    • 2012
  • It was known that triphenyl phosphate wasn't homogeneously dispersed in HDPE/EPDM/boron carbide blends, which caused the decrease in mechanical properties. HDPE, EPDM, boron carbide, and triphenyl phosphate were blended with PE-g-MAH(polyethylene-graft-maleic anhydride) as a compatiblizer for improving the miscibility of triphenyl phosphate. Tensile strength of HDPE/EPDM/boron carbide blends decreased with increasing the contents of triphenyl phosphate for flammability. However, the mechanical properties of HDPE/EPDM/boron carbide/triphenyl phosphate blends increased by the addition of compatiblizer because triphenyl phosphate was homogeneously mixed in the blend system. The homogeneous dispersibility of triphenyl phosphate was confirmed by using scanning electron microscopy (SEM). Increased thermal stability and flammability derived from high miscibility of triphenyl phosphate were confirmed by the results of thermogravimetric analysis (TGA) and limiting oxygen index (LOI). A self-extinguishing HDPE/EPDM/boron carbide/triphenyl phosphate blend was successfully fabricated with more than 21% LOI.

Effects of NaCl/H3PO4 Flame Retardant Treatment on Lyocell Fiber for Thermal Stability and Anti-oxidation Properties (NaCl/H3PO4 내염화 처리가 라이오셀 섬유의 열 안정 및 내산화 특성에 미치는 영향)

  • Kim, Eun Ae;Bai, Byong Chol;Jeon, Young-Pyo;Lee, Chul Wee;Lee, Young-Seak;In, Se Jin;Im, Ji Sun
    • Applied Chemistry for Engineering
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    • v.25 no.4
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    • pp.418-424
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    • 2014
  • The improved thermal stability and anti-oxidation properties of Lyocell fiber were studied based on flame retardant treatment by using NaCl/$H_3PO_4$ solution. The optimized conditions of flame retardant treatment were studied on various maxing ratio of NaCl and $H_3PO_4$ and the mechanism was proposed through experimental results of thermal stability anti-oxidation. The IPDT (integral procedural decomposition temperature), LOI (limited oxygen index) and $E_a$ (activation energy) increased 23, 30 and 24% respectively via flame retardant treatment. It is noted that thermal stability and anti-oxidation improved based on char and carbon layer formation by dehydrogenation and dissociation of C-C bond resulting the hindrance of oxygen and heat energy into polymer resin. The optimized conditions for efficient flame retardant property of Lyocell fiber were provided using NaCl/$H_3PO_4$ solution and the mechanism was also studied based on experimental results such as IDT (initial decomposition temperature), IPDT, LOI and $E_a$.

A Study on the Preparation of Powder Coatings Containing Halogen-Free Flame Retardant and Fire Safety (Halogen-Free 난연제를 포함하는 파우더 코팅소재 제조 및 화재안전성 연구)

  • Lee, Soon-Hong;Chung, Hwa-Young;Kim, Dae-In;Noh, Tae-Joon
    • Journal of the Korean Society of Safety
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    • v.26 no.4
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    • pp.47-58
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    • 2011
  • Halogen free intumescent flame retardants(IFRS), such as the mixture of melamine phosphate(MP) and char forming agents(pentaerythritol(PER), di-pentaerythritol(DiPER), tris(2-hydroxyethyl) isocyanurate(THEIC)), were prepared and characterized. Polypropylene(PP)/$IFR_S$ composites were also prepared in the presence of ethylene diamine phosphate(EDAP) as a synergist and used into flame retardant PP powder coatings. Thermoplastic PP powder coatings at 20 wt% flame retardant loading were manufactured by extruded and then mechanical cryogenic crushed to bring them in fine powder form. These intumescent flame retardant powder coatings($IFRPC_S$) were applied on mild steel surface for the purpose of protection and decorative. It is a process in which a $IFRPC_S$ particles coming in contact with the preheated mild steel surface melt and form a thin coating layer. The obtained MP flame retardant was analyzed by utilizing FTIR, solid-state $^{31}P$ NMR, ICP, EA and PSA. The mechanical properties as tensile strength, melt flow index(MFI) and the thermal property as TGA/DTA and the fire safety characteristics as limiting oxygen index(LOI), UL94 test, SEM were used to investigate the effect of $IFRPC_S$. The experimental results show that the presence of $IFR_S$ considerably enhanced the fire retardant performances as evidenced by the increase of LOI values 17.3 vol% and 32.6 vol% for original PP and $IFRPC_S$-3(PP/MP-DiPER/EDAP), respectively, and a reduction in total flaming combustion time(under 15 sec) in UL94 test of $IFRPC_S$. The prepared $IFRPC_S$-3 have good comprehensive properties with fire retardancy 3.2 mm UL94 V-0 level, LOI value 32.6%, tensile strength $247.3kg/cm^2$, surface roughness Ra $0.78{\mu}m$, showing a better application prospect. Through $IFRPC_S$-2(PP/MP-PER/EDAP) and $IFRPC_S$-3 a better flame retardancy than that of the $IFRPC_S$-1(PP/MP/EDAP) was investigated which was responsible for the formed more dense and compact char layer, improved synergy effect of MP and PER/DiPER.

A Study on the Ignitibility of Wooden Flooring (목질바닥재의 착화특성에 관한 연구)

  • Kim, Hae-Rim;Kim, Young-Tak;Park, Young-Ju;Lee, Hae-Pyeong
    • Proceedings of the Korea Institute of Fire Science and Engineering Conference
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    • 2008.11a
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    • pp.397-402
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    • 2008
  • In this study, we analyzed the ignitibility of the wooden floorings used as the finishing materials for interior with the flammability tester and the ignition point tester. Also we analyzed the limit oxygen index(LOI) using the oxygen index tester and the flame resistance of the wooden floorings. We confirmed that all of the samples had a excellent flame resistance. The ignitibility of the floorings were ranked as the material lumber>the strengthening flooring>the veneer board(1)>the veneer board(2).

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