• Title/Summary/Keyword: limited oxygen index (LOI)

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Non-durable Flame Retardant Finish of Cotton Fabric by Borax and Boric Acid (Borax 및 Boric Acid에 의한 면직물의 일시적 방염 가공)

  • 남상우
    • Journal of the Korean Home Economics Association
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    • v.25 no.1
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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.

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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.

Mechanical Properties and Flame Retardancy of Rigid Polyurethane Foam Using New Phosphorus Flame Retardant (새로운 인계 난연제 합성과 이를 이용한 경질 폴리우레탄 폼의 난연성 및 물성 분석)

  • Lee, Byoung Jun;Kim, Sang Bum
    • Applied Chemistry for Engineering
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    • v.27 no.6
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    • pp.577-582
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    • 2016
  • In this study, we compared and analyzed the flame retardancy and mechanical properties of three different rigid polyurethane foams (RPUF) containing noble non-halogen phosphorus flame retardant (BHP-RPUF) or halogen-phosphorus flame retardant (TCPP-RPUF) or no flame retardant material (Pure-RPUF). The noble phosphorus-based flame retardant, bis(3-(3-hydroxypropoxy)propyl) phenyl phosphate (BHP), was synthesized by the reaction between disodium phenyl phosphate and 3-chloro-1-propanol. Through universal testing machine (UTM) experiments, the compressive strength of BHP-RPUF was similar to that of TCPP-RPUF. From the result of foam morphology analysis, it was confirmed that BHP-RPUF has the lowest thermal conductivity of $0.023W/m{\cdot}K$. We also measured the size of air bubbles using reaction velocity and SEM, and analyzed how they affect the thermal conductivity. In addition, the heat-resisting property was investigated through TGA analysis. The limited oxygen index (LOI) test confirmed that BHP had the ability to increase the flame retardancy of RPUF.

Multi-Functional Finish of Polyester and P/C blend Fabrics by Corona Discharge(II) - Multifunctional finish- (코로나 방전처리에 의한 폴리에스테르 및 P/C 혼방직물의 복합기능화 가공(II) - 복합 기능화 가공 -)

  • Lee, Bang One;Pak, Pyong Ki;Yeo, Joo Hong;Lee, Hwa Sun
    • Textile Coloration and Finishing
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    • v.9 no.3
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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.

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A Study on the Preparation of Thermoplastic Powder Coating Material and Its Flame Retardancy (열가소성 분말 코팅소재 제조 및 난연특성 연구)

  • Lee, Soon-Hong;Chung, Hwa-Young
    • Journal of the Korean Society of Safety
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    • v.25 no.3
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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 $Mg(OH)_2$.

Synthesis and Properties of Polybenzoxazole Precursors having Oligo(oxy ethylene) pendant (Oligo(oxy ethylene) pendant를 갖는 PBO 전구체의 합성 및 특성)

  • Lee, Eung-Jae;Yoon, Doo-Soo;Bang, Moon-Soo;Choi, Jae-Kon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.5
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    • pp.2550-2558
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    • 2013
  • Poly(o-hydroxyamides)(PHAs) copolymers having oligo(oxy ethylene) pendant in the main chain were synthesized by solution polycondensation reaction at low temperature. Copolymer precursors were studied by fourier transform infrared(FT-IR), differential scanning calorimeter(DSC), thermogravimetric analyzer(TGA), universal testing machine(UTM) and limited oxygen index(LOI). The inherent viscosities of the PHAs measured at $35^{\circ}C$ in DMAc or DMAc/LiCl solution were in the range of 0.74~1.42 dL/g. Solubility of the precursors with higher oligo(oxy ethylene) unit was increased, but the PBOs were nearly insoluble in a variety of solvents. The degradation temperature of the copolymer precursors was recorded in the ranges of $408{\sim}664^{\circ}C$ in nitrogen and char yields showed 13~59% values at $900^{\circ}C$. The mechanical properties and flame retardancy of copolymer precursors decreased with higher oligo(oxy ethylene) unit.

Fire-Retardation Properties of Polyurethane Nanocomposite by Filling Inorganic Nano Flame Retardant (폴리우레탄 복합체의 무기난연재료 충전에 의한 난연 특성)

  • Son, Bok-Gi;Hwang, Taek-Sung;Goo, Dong-Chul
    • Polymer(Korea)
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    • v.31 no.5
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    • pp.404-409
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    • 2007
  • Polyurethane nanocomposites with inorganic nano fillers for the improvement thermal stability were prepared by the urethane reaction. Fire retardation properties of polyurethane nanocomposites were investigated by cone calorimeter and limited oxygen index (LOI). Maximum heat release rate of MMT-PU and $Bi_2O_3-PU$ polyurethane nanocomposites were decreased as 50% than polyurethane matrix and fire retardation properties of $MMT/Bi_2O_3-PU$ nanocomposte had the best improvement. The LOI of polyurethane nanocomposites also were improved as filling fillers in the nanocomposites over 20. The maximum heat release rates of MMT-PU, $Bi_2O_3-PU\;and\;MMT/Bi_2O_3-PU$ polyurethane nanocomposites were 764, 707, $635kW/m^2$, respectively and $MMT/Bi_2O_3-PU$ polyurethane nanocomposite exhibited the highest value of fire-retardant. We confirmed that polyurethane nanocomposites improved the fire retardation properties.

Styrene-free Synthesis of Flame-retardant Vinyl Ester Resin Films for Hot-melt Prepreg Process (핫멜트 프리프레그 공정용 난연성 비닐에스터 수지 필름의 무 스티렌 합성)

  • Jiseon, Kang;Minji, Kim;Mongyoung, Huh;Seok Il, Yun
    • Composites Research
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    • v.35 no.6
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    • pp.412-418
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    • 2022
  • Flame-retardant vinyl ester (VE) resin films were developed from the mixtures of brominated and non-brominated epoxy resins via esterification with methacrylic acid without reactive diluents. The films were used to fabricate carbon fiber (CF) prepregs via a hot melt impregnation process. The viscosity of VE resins suitable for film production was optimized by mixing low-viscosity bisphenol-A and high-viscosity brominated bisphenol-A epoxy precursors. Increasing the bromine content of the cured VE resin further increased the limited oxygen index (LOI) (39%), storage modulus (2.4 GPa) at 25℃ and residual carbonization (16.1%) values compared to non-brominated VE. Manual layup of as-prepared VE prepregs with subsequent curing led to the successful fabrication of CF-reinforced composites with high tensile and flexural strength. The results from the study hold high promise for a styrene-free, environmentally friendly VE composite process in the future.

Effect of Flame Retardants on Flame Retardancy of Rigid Polyurethane Foam (난연제 종류에 따른 경질 폴리우레탄 폼의 난연 특성)

  • Kim, Keunyoung;Seo, Wonjin;Lee, Ju-Chan;Seo, Jung-Seok;Kim, Sangbum
    • Journal of the Korean Institute of Gas
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    • v.17 no.5
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    • pp.75-80
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    • 2013
  • In this study, the effect of phosphorus flame retardants on the flame retardancy of the rigid polyurethane foam(PUF) was studied. Tetramethylene bis(orthophos-phorylurea)[TBPU] and Tris(2-chloroethyl) phosphate[TCEP], Tris(2-chloropropyl)phosphate [TCPP], Triethyl phosphate[TEP] were used as flame retardant. It was found that TBPU added PUF exhibits low mean heat release rate(HRR), peak HRR, effective heat of combusion(EHC), mass loss rate (MLR), CO yield and $CO_2$ compared other flame retardants.

Comparison of Magnesium Hydroxide Particles by Precipitation and Hydrothermal Treatment for Flame Retardant Application to Low Density Polyethylene and Ethylene-Co-Vinyl Acetate Resin (침전법과 수열처리로 제조된 수산화마그네슘 비교와 이의 저밀도 폴리에틸렌-에틸렌 비닐 아세테이트 수지 난연제 적용)

  • Hyun, Mi Kyung;Lim, Hyung Mi;Yoon, Joonho;Lee, Dong Jin;Lee, Seung-Ho;Whang, Chin Myung;Jeong, Sang Ok
    • Applied Chemistry for Engineering
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    • v.20 no.2
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    • pp.234-240
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    • 2009
  • $Mg(OH)_2$ particles were prepared by precipitation and a hydrothermal treatment to examine the effect of $MgCl_2$ concentration, alkali type and concentration, temperature, hydrothermal treatment on the formation of $Mg(OH)_2$ particles using full factorial design, as one of DOE (Design of experiment) methods. The primary particle size is similar to the secondary particle size for the samples after the hydrothermal treatment, where the average particle size of $Mg(OH)_2$ increased with increasing the concentration of $MgCl_2$ and hydrothermal temperature and decreasing alkali/Mg molar ratio. On the other hand, for the samples prepared from precipitation, the secondary particle size is larger than the primary particles due to aggregation. The difference in alkaline source is that the particles prepared from $NH_4OH$ exhibit the larger size with better dispersion than those from NaOH. Low density polyethylene and ethylene-co-vinyl acetate (LDPE-EVA) resin composed of the smaller secondary particle size of $Mg(OH)_2$ shows a higher limited oxygen index (LOI) at 50 and 55% loading, but the smaller primary particle size may result in a better grade in UL-94 tests. At the high loading of 60%, all samples with any preparation methods exhibit V-0 grade but the LOI value depends on not only primary particle size but also dispersion state.