scholarly journals Chemical Modification of Expandable Graphite by Boric Acid and Its Flame Retarded Application in Polyethylene

2018 ◽  
pp. 34-39
Author(s):  
Ya-Fang Meng ◽  
Xiu-Yan Pang ◽  
Wei-Shu Chang
Keyword(s):  
Thermal Stability ◽  
Boric Acid ◽  
Intercalation Compound ◽  
Expandable Graphite ◽  
Linear Low Density Polyethylene ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Graphite Intercalation ◽  
Pure Matrix ◽  
Flame Retarded

The aim of this research is to get the graphite intercalation compound with high thermal stability and fire resistance. Firstly, the normal expandable graphite (EG) was prepared with potassium permanganate (KMnO4) as oxidant and sulfuric acid (H2SO4) as intercalator, respectively. Then, with (3-Aminopropyl)-trimethoxysilane (KH-550) as coupling agent, the boric acid (H3BO3) modified EG (EGB) was prepared by silane grafting method through H3BO3 bonded with EG. The analysis of X-ray powder diffractiometer and Fourier transform infrared spectroscopy testified the existence of EGB. EGB showed better thermal stability and flame retardancy for linear low density polyethylene (LLDPE) than the referenced EG. Addition of 13.0 wt% of EGB improved the limiting oxygen index (LOI) of 87.0LLDPE/13.0EGB to 24.6%, which was obviously higher than that of pure matrix of 17.5%. Whereas, the LOI of 87.0LLDPE/13EG was 22.7%. Furthermore, when EGB combined with ammonium polyphosphate (APP), the LOI and UL-94 level of 87.0LLDPE/8.7EGB/4.3APP reached 27.1% and V-0, respectively.

Structural Evolution of Natural Flake Graphite during Intercalation and Exfoliation

2014 ◽  
Vol 552 ◽  
pp. 328-330
Author(s):  
Zhi Guo Liu
Keyword(s):  
Intercalation Compound ◽  
Structural Evolution ◽  
Expanded Graphite ◽  
Expandable Graphite ◽  
Flake Graphite ◽  
Graphite Intercalation Compound ◽  
X Ray Diffraction ◽  
Natural Graphite ◽  
X Ray ◽  
Graphite Intercalation

In order to investigate the structural evolution of natural flake graphite during intercalation and exfoliation, natural graphite flakes were treated by intercalating, water-washing, drying and expanding. The corresponding products, graphite intercalation compound (GIC), residue GIC (expandable graphite) and expanded graphite were characterized by X-ray diffraction (XRD). The results can provide reference for the research in this field.

scholarly journals Rotomolded antistatic and flame-retarded graphite nanocomposites

2017 ◽  
Vol 31 (4) ◽  
pp. 535-552 ◽  
Author(s):  
Washington Mhike ◽  
Walter W Focke ◽  
Joseph KO Asante
Keyword(s):  
Outer Layer ◽  
Cone Calorimeter ◽  
Average Particle Size ◽  
Expandable Graphite ◽  
Average Particle ◽  
Linear Low Density Polyethylene ◽  
Graphite Nanoplatelets ◽  
Flame Retarded ◽  
Poly Ethylene ◽  
Graphite Nanocomposites

Graphite nanoplatelets with an average particle size of 13 μm and an estimated flake thickness of about 76 nm were prepared by microwave exfoliation, followed by ultrasonication-assisted liquid-phase delamination, of an expandable graphite. This nanoadditive was used to fabricate linear low-density polyethylene (LLDPE) and poly(ethylene-co-vinyl acetate) (EVA)-based nanocomposite sheets using rotational molding. The dry blending approach yielded surface resistivities within the static dissipation range at filler loadings as low as 0.25 wt.% (0.1 vol.%). However, even at this low graphite content, impact properties were significantly reduced compared to the neat polymers. Bilayer moldings via the double dumping method proved to be a feasible approach to achieve both acceptable mechanical properties and antistatic properties. This was achieved by rotomolding nanocomposite sheets with a 1-mm outer layer containing the filler and a 2-mm inner layer of neat LLDPE. Excellent fire resistance, in terms of cone calorimeter testing, was achieved when the outer layer also contained 10 wt.% expandable graphite.

X-ray investigation of highly saturated Li-graphite intercalation compound

Carbon ◽  
1995 ◽  
Vol 33 (2) ◽  
pp. 177-181 ◽  
Author(s):  
V.A. Nalimova ◽  
D. Guérard ◽  
M. Lelaurain ◽  
O.V. Fateev
Keyword(s):  
Intercalation Compound ◽  
Graphite Intercalation Compound ◽  
X Ray ◽  
Graphite Intercalation

Preparation and Characterization of Excellent Flame Retarded Rigid Polyurethane Foams

2011 ◽  
Vol 374-377 ◽  
pp. 1563-1566
Author(s):  
An Zhen Zhang ◽  
Yi He Zhang
Keyword(s):  
Flame Retardant ◽  
Flame Retardants ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Dimethyl Methylphosphonate ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Foaming Process ◽  
Flame Retarded

Rigid polyurethane foams were excellent thermal insulation materials with widely used, which was highly flammable at the same time. In order to obtain safe application, flame retarded polyurethane foams were needed. In this paper, series flame retarded rigid polyurethane foams were prepared with loading different flame retardants such as ammonium polyphosphate, expandable graphite, red phosphorus, Tri (2-chloroethyl) phosphate and dimethyl methylphosphonate. The effects of flame retardants on the foaming-process and flame retardant property of the rigid polyurethane foams were investigated by otary viscometer and limiting oxygen index. The results showed that the combination of solid and liquid flame retardants was necessary to improve the flame retardant and different flame retardants played synergistic roles in rigid polyurethane foams. The limiting oxygen indexes of the foams could be up to 30wt% and 29.6% with 25wt% solid flame retardants and 10wt% liquid retardants, respectively.

Sonochemically Synthesis of Antimonite Nanoparticles and Its Influence on the Thermal Stability of the ABS Terpolymer

2013 ◽  
Vol 32 (4) ◽  
pp. 339-343 ◽  
Author(s):  
Siyamak Bagheriyan
Keyword(s):  
Thermal Stability ◽  
Acrylonitrile Butadiene Styrene ◽  
X Ray Diffraction ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Sonochemical Reaction ◽  
Ft Ir ◽  
Higher Temperature ◽  
Thermal Stability Of ◽  
Butadiene Styrene

AbstractSb2S3 nanoparticles were synthesized via a simple sonochemical reaction between SbCl3 and thioacetamide. The effect of different parameters such as power and time of pulsation on the morphology of the product has been investigated. The Sb2 S3 nanostructures were then added to acrylonitrile-butadiene-styrene terpolymer. The effect of Sb2 S3 nanostructures on the thermal stability of the polymeric matrix has been examined. The thermal decomposition of the nanocomposite shifts towards higher temperature in the presence of the Sb2 S3 . Nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FT-IR), photoluminescence (PL) spectroscopy, thermogravimetric analysis (TGA), UL-94 and limiting oxygen index (LOI) analysis.

Preparation of FeCl3–IBr–H2SO4–graphite multi-intercalation compounds

1994 ◽  
Vol 9 (2) ◽  
pp. 377-382 ◽  
Author(s):  
Takeshi Abe ◽  
Yasuo Mizutani ◽  
Eiji Ihara ◽  
Mitsuru Asano ◽  
Toshio Harada
Keyword(s):  
Saturated Vapor ◽  
Intercalation Compound ◽  
Intercalation Compounds ◽  
Stacking Sequence ◽  
X Ray Diffraction ◽  
Graphite Intercalation Compounds ◽  
X Ray ◽  
Graphite Intercalation ◽  
Diffraction Patterns

Stages 4-6 FeCl3-graphite intercalation compounds (GIC's) have been prepared by an ordinary two-bulb method, and FeCl3-IBr-graphite bi-intercalation compounds (GBC's) are synthesized by holding the FeCl3-GIC's in the saturated vapor of IBr. The x-ray diffraction patterns of the FeCl3-IBr-GBC's obtained from stages 4, 5, and 6 FeCl3-GIC's give the stacking sequences as G(FeCl3)GG(IBr)GG(FeCl3)G, G(FeCl3)GG(IBr)GGG(FeCl3)G, and G(FeCl3)GG(IBr)GG(IBr)GG(FeCl3)G, respectively, where G, (FeCl3), and (IBr) refer to the graphite, FeCl3, and IBr layers, respectively. The multi-intercalation of H2SO4 into the FeCl3-IBr-GBC's synthesized from stages 4 and 6 FeCl3-GIC's occurs at all the vacant galleries of the GBC's at the same time. In contrast, the multi-intercalation of H2SO4 into the FeCl3-IBr-GBC obtained from the stage 5 FeCl3-GIC takes place in two processes. The first multi-intercalation occurs at the gallery adjacent to the bi-intercalated IBr layer, and the stacking sequence of the resulting graphite multi-intercalation compound is determined to be G(FeCl3)GG(IBr)G(H2SO4)GG(FeCl3)G, where (H2SO4) refers to the H2SO4 layer. The second multi-intercalation occurs at all the rest of the vacant galleries.

Preparation of stages 2–4 ternary AlCl3–FeCl3-graphite intercalation compounds

1995 ◽  
Vol 10 (5) ◽  
pp. 1196-1199 ◽  
Author(s):  
Takeshi Abe ◽  
Yasuo Mizutani ◽  
Mitsuru Asano ◽  
Toshio Harada
Keyword(s):  
Vapor Pressure ◽  
Gas Phase ◽  
Intercalation Compound ◽  
Intercalation Compounds ◽  
Graphite Intercalation Compound ◽  
X Ray Diffraction ◽  
Vapor Species ◽  
Graphite Intercalation Compounds ◽  
X Ray ◽  
Graphite Intercalation

Intercalation of AlCl3 into stage 2 FeCl3-graphite intercalation compound (GIC) using an ordinary two-bulb method has been studied by x-ray diffraction. Stages 2, 3, and 4 ternary AlCl3-FeCl3-GlC's are obtained when the temperatures of the stage 2 FeCl3-GIC were set at T (GIC) = 503, 523, and 553 K, respectively, for the AlCl3 intercalate material at T (AlCl3) = 473 K, that is, the vapor pressure of (AlCl3)2 (g) of the main vapor species to be held at p {(AlCl3)2} = 2.4 × 105 Pa. However, for the temperature of the stage 2 FeCl3-GIC at T (GIC) = 573 K, the (AlCl3)2 (g) vapor is found to promote the decomposition of the stage 2 FeCl3-GIC, resulting in the formation of graphite. The decomposition of the stage 2 FeCl3-GIC is considered to take place because the complex AlFeCl6 (g) in the gas phase, which is formed from both (AlCl3)2 (g) and FeCl3 existing at the edge of the FeCl3-GIC, is thermodynamically more stable than the FeCl3 and AlCl3 intercalates in their GIC at p {(AlCl3)2} = 2.4 × 105 Pa and T (GIC) = 573 K.

Novel approaches for controlling stage structure of metal chloride–graphite intercalation compounds

2002 ◽  
Vol 17 (12) ◽  
pp. 3190-3192 ◽  
Author(s):  
H. Shioyama ◽  
M. B. H. M. Saman ◽  
A. Sanpanich
Keyword(s):  
Intercalation Compound ◽  
Stage Structure ◽  
Graphite Intercalation Compound ◽  
X Ray Diffraction ◽  
X Ray ◽  
Stage 4 ◽  
Graphite Intercalation ◽  
Structure Of Metal ◽  
Stage Transition ◽  
Stage 1

Intercalation of EuCl3 TbCl3, and AlCl3 into graphite was carried out in the presence of chlorine. The observation of products by x-ray diffraction showed that the extent of chloride intercalation could be controlled through adjustment of the pressure of chlorine; increasing pressure tended to increase the extent of intercalation. In the case of EuCl3, the extent of intercalation varied to show a stage transition. In contrast, TbCl3 intercalation gave a mixture of stage 2 or stage 4 graphite intercalation compound (GIC) and remaining graphite, where the extent of intercalation is revealed by the ratio of GIC to graphite. With respect to AlCl3 intercalation, although the preparation of stage 1, 2, and 4 GICs was successful, stage 3 and 5 GICs could not be obtained.

scholarly journals Effects of chemical pre-treatment on structure and property of polyacrylonitrile based pre-oxidized fibers

2020 ◽  
Vol 15 ◽  
pp. 155892501989894
Author(s):  
Xiaolu Sun ◽  
Jiayin Song ◽  
Jin Zhang ◽  
Jingyan Liu ◽  
Huizhen Ke ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Heat Release ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Energy Dispersive Spectrometer ◽  
Chemical Compositions ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Pre Treatment

Polyacrylonitrile-based pre-oxidized fibers with improved thermal stability, flame retardant, and mechanical properties were made from the pristine polyacrylonitrile fibers through chemical pretreatment followed by pre-oxidation in air. The morphological structure of the polyacrylonitrile-based pre-oxidized fibers was investigated by Fourier transfer infrared spectra, X-ray diffraction, scanning electron microscopy, and X-ray energy dispersive spectrometer. The changes of characteristic functional groups and chemical compositions confirmed the successful modification of the polyacrylonitrile fibers during pre-treatment. The grooves and cracks on the surface of polyacrylonitrile-based pre-oxidized fibers were remarkably decreased in comparison with that of pristine polyacrylonitrile fibers. The evolution of crystalline structure of the polyacrylonitrile fibers proved the occurrence of cyclization reactions during pre-oxidation. Meanwhile, thermal stability, flame retardant, and mechanical properties of polyacrylonitrile-based pre-oxidized fibers were also investigated by thermogravimetric analyzer, oxygen index meter, micro combustion calorimeter, and single fiber tensile tester, respectively. The results demonstrated that the polyacrylonitrile-based pre-oxidized fibers initially pre-treated by hydroxylamine hydrochloride, followed by monoethanolamine, had a high limiting oxygen index of 40.1 and breaking strength of 2.03 cN/dtex. The peak of heat release rate and total heat release of polyacrylonitrile-based pre-oxidized fibers decreased significantly while its charred residues increased, contributing to the improved flame retardant property.

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