Impact of graphene oxide on epoxy resin characteristics

2020 ◽  
pp. 095400832094392
Author(s):  
Maziyar Sabet ◽  
Hassan Soleimani ◽  
Seyednooroldin Hosseini ◽  
Erfan Mohammadian
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Heat Release ◽  
Fire Resistance ◽  
Fire Retardant ◽  
Polymer Chains ◽  
Limiting Oxygen Index ◽  
Limited Mobility ◽  
Smoke Production ◽  
Smoke Density

The incorporation of a small part of graphene oxide (GO) offers an appropriate fire retardant for thermally conductive epoxy (EP) resin composites, which is verified by the upper limiting oxygen index of 24.5% and other standard flame-retardant tests. The smoke production rate, total smoke production (TSP), and the smoke density of EP composites were reduced with additional GO. The increased efficiency of fire resistance and smoke suppression is primarily due to the formation of physical barrier and compactness of the developed GO char layers, serving as an effective barrier layer that increases the fire resistance, and the thermal steadiness of the char layers derives from the effect of GO inclusion. The barrier impact of GO and the limited mobility of polymer chains are crucial factors in increasing thermal stability and reduction of generating dangerous carbon monoxide during burns. The thermal stability increased and the peak heat release rate, total heat release, TSP, and the largest smoke density value reduced to 52.5%, 43.6%, 33.9%, and 44.2%, correspondingly, compared with pure EP. The tensile strength and elongation at break of EP composites were enhanced by 23% and 8.4% compared with pure EP, respectively.

Synergistic Effect between Modified Graphene Oxide and Ammonium Polyphosphate on Combustion Performance, Thermal Stability and Mechanical Properties of Polylactic Acid

2021 ◽  
Vol 36 (4) ◽  
pp. 367-378
Author(s):  
X.-Y. Pang ◽  
Y.-F. Meng ◽  
Y.-P. Xin ◽  
R. Chang ◽  
J.-Z. Xu
Keyword(s):  
Mechanical Properties ◽  
Thermal Stability ◽  
Graphene Oxide ◽  
Heat Release ◽  
Polylactic Acid ◽  
Network Structure ◽  
Ammonium Polyphosphate ◽  
Limiting Oxygen Index ◽  
Combustion Performance ◽  
Modified Graphene Oxide

Abstract To improve the thermal stability, ZF-GO (graphene oxide (GO) modified by zinc ferrite (ZF)) is prepared. In view of the anti-dripping function of ZF-GO and flame retardant effect of ammonium polyphosphate (APP), the influence of ZF-GO, APP, mixture of ZF-GO and APP on combustion performance, thermal stability and mechanical properties of polylactic acid (PLA) is investigated. Results show that the modification of GO by ZF significantly improves the residue of ZFGO by 34.7%. The char-forming capability and unique network structure of ZF-GO prevent the melt dripping of PLA. Although APP can increase the limiting oxygen index of PLA, there is still melt dripping. The combination of ZF-GO and APP improves the residual yield of 94PLA/3ZF-GO/3APP by 4.3 times relative to pure PLA, and the UL-94 level reaches V-0. The two additives show synergistic char-forming effect, and there is both physical carbonization and chemical carbonization. The incorporated fillers can decrease the total heat release (THR) of PLA composites. Specifically, the THR and peak value of heat release rate of 94PLA/3ZF-GO/3APP decrease by 21.2% and 53.9%, respectively. For the PLA/ZF-GO/APP system, plenty of residues and the anti-dripping network structure are key factors to get good flame retardancy. Addition of ZFGO and APP reduces the tensile strength, but the tensile elongation of the modified PLA composites is improved. 94PLA/ 3ZF-GO/3APP shows good integrated performance.

Comparison of silicate impregnation methods to reinforce Chinese fir wood

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Ping Li ◽  
Yuan Zhang ◽  
Yingfeng Zuo ◽  
Yiqiang Wu ◽  
Guangming Yuan ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Heat Release ◽  
Flame Retardancy ◽  
Chinese Fir ◽  
Smoke Suppression ◽  
Impregnation Method ◽  
Residual Rate ◽  
Smoke Production ◽  
Human Respiration ◽  
Strengthen Effect

AbstractInorganic impregnation strengthening of Chinese fir wood was carried out to improve the strength, dimensional stability, flame retardancy, and smoke suppression of Chinese fir wood. Sodium silicate was used as reinforcement, a sulfate and phosphate mixtures were used as a curing agent, and Chinese fir wood was reinforced by the respiratory impregnation method (RIM) that imitating human respiration and vacuum progressive impregnation method (VPIM). The weight percentage gain (WPG), density increase rate, distribution of modifier, bending strength (BS), compressive strength (CS), hardness, and water resistance of unreinforced Chinese fir wood from the VPIM and RIM were compared. It was found that RIM could effectively open the aspirated pits in Chinese fir wood, so its impregnation effect, strengthen effect and dimension stabilization effects were the best. RIM-reinforced Chinese fir wood was filled with silicate both horizontally and vertically. At the same time, the transverse permeability of silicate through aspirated pits was significantly improved. The chemical structure, crystalline structure, flame retardancy, smoke suppression, and thermal stability of VPIM- and RIM-reinforced Chinese fir wood were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), cone calorimeter (CONE), and thermogravimetric analysis (TGA). The results indicated that although the crystallinity of RIM-reinforced Chinese fir wood decreased the most, more chemical crosslinking and hydrogen bonding were formed in the wood, and the strengthen effect was still the best. Compared with VPIM-reinforced Chinese fir wood, RIM-reinforced Chinese fir wood had lower heat release rate (HRR), peak-HRR, mean-HRR, total heat release (THR), smoke production rate (SPR), and total smoke production (TSP), higher thermal decomposition temperature and residual rate. It was indicated that RIM-reinforced Chinese fir wood was a better flame retardant, and has a smoke suppression effect, thermal stability, and safety performance in the case of fire.

scholarly journals Preparation of Ion-Exchanged TEMPO-Oxidized Celluloses as Flame Retardant Products

Molecules ◽  
2019 ◽  
Vol 24 (10) ◽  
pp. 1947
Author(s):  
Cunzhen Geng ◽  
Zhihui Zhao ◽  
Zhixin Xue ◽  
Peilong Xu ◽  
Yanzhi Xia
Keyword(s):  
Thermal Stability ◽  
Ion Exchange ◽  
Heat Release ◽  
Textile Industry ◽  
Large Scale ◽  
13C Nmr Spectroscopy ◽  
Commercial Application ◽  
Limiting Oxygen Index ◽  
13C Nuclear Magnetic Resonance ◽  
Microscale Combustion Calorimetry

Cellulose, as one of the most abundant natural biopolymers, has been widely used in textile industry. However, owing to its drawbacks of flammability and ignitability, the large-scale commercial application of neat cellulose is limited. This study investigated some TEMPO-oxidized cellulose (TOC) which was prepared by selective TEMPO-mediated oxidation and ion exchange. The prepared TOC was characterized by Fourier transform infrared (FT-IR) spectroscopy and solid-state 13C-nuclear magnetic resonance (13C-NMR) spectroscopy. The thermal stability and combustion performance of TOC were investigated by thermogravimetry analysis (TG), microscale combustion calorimetry (MCC) and limiting oxygen index (LOI). The results demonstrated that the thermal stability of TOC was less than that of the pristine material cellulose, but the peak of heat release rate (pHHR) and the total heat release (THR) of all TOC were significantly reduced. Additionally, the LOI values of all TOC products were much higher 25%. In summary, the above results indicated that the modified cellulose with carboxyl groups and metal ions by selective oxidation and ion exchange endows efficient flame retardancy.

scholarly journals Development of Biodegradable Flame-Retardant Bamboo Charcoal Composites, Part I: Thermal and Elemental Analyses

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2217 ◽  
Author(s):  
Shanshan Wang ◽  
Liang Zhang ◽  
Kate Semple ◽  
Min Zhang ◽  
Wenbiao Zhang ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Residue Analysis ◽  
Fire Retardant ◽  
Protective Layer ◽  
Growth Index ◽  
Raw Material ◽  
Bamboo Charcoal ◽  
Limiting Oxygen Index ◽  
Plastic Composite

In this study, bamboo charcoal (BC) was used as a substitute filler for bamboo powder (BP) in a lignocellulose-plastic composite made from polylactic acid (PLA), with aluminum hypophosphite (AHP) added as a fire retardant. A set of BC/PLA/AHP composites were successfully prepared and tested for flame-retardancy properties. Objectives were to (a) assess compatibility and dispersibility of BC and AHP fillers in PLA matrix, and (b) improve flame-retardant properties of PLA composite. BC reduced flexural properties while co-addition of AHP enhanced bonding between PLA and BC, improving strength and ductility properties. Adding AHP drastically reduced the heat release rate and total heat release of the composites by 72.2% compared with pure PLA. The formation of carbonized surface layers in the BC/PLA/AHP composites effectively improved the fire performance index (FPI) and reduced the fire growth index (FGI). Flame-retardant performance was significantly improved with limiting oxygen index (LOI) of BC/PLA/AHP composite increased to 31 vol%, providing a V-0 rating in UL-94 vertical flame test. Adding AHP promoted earlier initial thermal degradation of the surface of BC/PLA/AHP composites with a carbon residue rate up to 40.3%, providing a protective layer of char. Further raw material and char residue analysis are presented in Part II of this series.

scholarly journals Manufacture of semi non-combustible wood-fiber insulation boards by inorganic fire-retardant treatment

BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 8235-8248
Author(s):  
Se-Hwi Park ◽  
Min Lee ◽  
Eun-Chang Kang ◽  
Sang-Min Lee ◽  
Kugbo Shim
Keyword(s):  
Heat Release ◽  
Fire Resistance ◽  
Cone Calorimeter ◽  
Wood Fiber ◽  
Fire Retardant ◽  
Fire Retardants ◽  
Total Heat Release ◽  
Complete Combustion ◽  
Resistance Performance ◽  
Co Emission

Fire-retardant performance was imparted to the existing wood-fiber insulation boards (WIB) via internal and external treatment with silica- and phosphorus-based fire-retardants. The combustion and smoke characteristics were investigated using a cone calorimeter. Based on combustion for 600 s, the weight loss and shrinkage of WIBs decreased due to fire-retardant treatment. The time to ignition was delayed to more than 400 s on the WIBs treated internal and external fire- retardant (WIB-IEs), whereas that of WIB with only internal treatment (WIB-I) was 5 s. The overall heat release rate (HRR), HRRpeak, and total heat release (THR) of WIB-IE specimens decreased, and the fire resistance standard Class II was satisfied. The WIB-IE2 showed higher fire resistance performance, with a HRRmean level of 6.7 kW/m2 and a THR of 1.3 MJ/m2. The WIB-I showed extremely low total smoke release (TSR) compared to the external fire-retardant treated specimen. However, the externally treated WIB-IEs had an increased TSR of 165 to 256 m2/m2 due to the increase in incomplete combustion caused by the fire-retardant. After fire-retardant treatment, CO2 generation decreased because the rate of complete combustion decreased, but CO emission increased slightly. Therefore, silica- and phosphorus-based fire-retardants by internal and external treatments were suitable for WIBs.

scholarly journals Decomposition and Flammability of Polyimide Graphene Composites

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 168
Author(s):  
Caroline Akinyi ◽  
Jimmy Longun ◽  
Siqi Chen ◽  
Jude O. Iroh
Keyword(s):  
Thermal Stability ◽  
Oxygen Index ◽  
Fire Retardant ◽  
Analysis Data ◽  
Condensation Polymerization ◽  
Limiting Oxygen Index ◽  
Thermally Stable Polymers ◽  
Decomposition Behavior ◽  
Polyimide Nanocomposite

Polyimide-graphene composites were synthesized by in-situ condensation polymerization and the thermal stability and decomposition behavior of the composites were studied. Polyimides, because of their aromatic backbone, are a class of fire-retardant polymers. Their high char retention ≥50% at testing temperatures ≥600 °C makes them thermally stable polymers. The effect of nanographene sheets on the decomposition behavior of polyimide is presented in this paper. It is shown that the reinforcement of polyimide with nanographene sheets significantly decreased the rate of decomposition of polyimide and increased the char retention of the composite. Thermogravimetric analysis data were used to assess the thermal stability, rate of mass loss and predicted limiting oxygen index of the neat polyimide and composites. Results obtained showed around a 43% decrease in the rate of polyimide degradation at 50 wt.% graphene loading. The limiting oxygen index of the polyimide nanocomposite was calculated by using the char retention, and it was found to increase by up to 24% at 50 wt.% graphene loading over that for the neat matrix.

scholarly journals Enhancement of Flame Retardancy and Mechanical Properties of Polylactic Acid with a Biodegradable Fire-Retardant Filler System Based on Bamboo Charcoal

Polymers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 2167
Author(s):  
Wenzhu Li ◽  
Liang Zhang ◽  
Weisheng Chai ◽  
Ningning Yin ◽  
Kate Semple ◽  
...  
Keyword(s):  
Heat Release ◽  
Polylactic Acid ◽  
Flame Retardancy ◽  
Chemical Elements ◽  
Fire Retardant ◽  
Strength Properties ◽  
Bamboo Charcoal ◽  
Adhesion Promoter ◽  
Limiting Oxygen Index ◽  
Air Atmosphere

A cooperative flame-retardant system based on natural intumescent-grafted bamboo charcoal (BC) and chitosan (CS) was developed for polylactic acid (PLA) with improved flame retardancy and minimal decline in strength properties. Chitosan (CS) as an adhesion promoter improved the interfacial compatibility between graft-modified bamboo charcoal (BC-m) and PLA leading to enhanced tensile properties by 11.11% and 8.42%, respectively for tensile strength and modulus. At 3 wt.% CS and 30 wt.% BC-m, the crystallinity of the composite increased to 38.92%, or 43 times that of pure PLA (0.9%). CS promotes the reorganization of the internal crystal structure. Thermogravimetric analysis showed significantly improved material retention of PLA composites in nitrogen and air atmosphere. Residue rate for 5 wt.% CS and 30 wt.% BC-m was 29.42% which is 55.1% higher than the theoretical value of 18.97%. Flammability tests (limiting oxygen index-LOI and UL-94) indicated significantly improved flame retardancy and evidence of cooperation between CS and BC-m, with calculated cooperative effectiveness index(Ce) >1. From CONE tests, the peak heat release rate (pHRR) and total heat release (THR) were reduced by 26.9% and 30.5%, respectively, for 3% CS + 20% BC-m in PLA compared with adding 20% BC-m alone. Analysis of carbon residue morphology, chemical elements and structure suggest CS and BC-m form a more stable char containing pyrophosphate. This char provides heat insulation to inhibit complete polymer pyrolysis, resulting in improved flame retardancy of PLA composites. Optimal mix may be recommended at 20% BC-m + 3% CS to balance compatibility, composite strength properties and flame retardance.

scholarly journals PREPARATION OF IRON- REDUCED GRAPHENE OXIDE/ EPOXY RESIN COMPOSITE AND ITS FLAME RETARDANCY AND THERMAL STABILITY

10.6036/10327 ◽  
2022 ◽  
Vol 97 (1) ◽  
pp. 98-103
Author(s):  
XIAN WANG ◽  
JINLONG ZHUO ◽  
TIANQING XING ◽  
Xingran Wang
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Iron Powder ◽  
Flame Retardancy ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Industrial Manufacture ◽  
Ul 94

In order to reduce flammability, smoke release and enhance thermal stability of epoxy resin (EP), iron powder is mixed with graphene oxide/ epoxy resin (GO/EP) composite by mechanical blending. The combustion performance of composite material is investigated through limiting oxygen index (LOI), Underwriters Laboratory (UL)-94 test, and cone calorimeter test (CCT). Thermogravimetric-Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) are also used to explore the mechanism of flame retardancy and smoke suppression. Results show that, with the addition of 0.5% mass fraction of GO and the corresponding iron powder combination (EP3 sample), the LOI value can achieve 32.5% while reaching the UL-94 V0 rating. Compare with EP0, the peaks of heat release rate, smoke production rate, and smoke factor values of EP3 are decreased by 42%, 60%, and 50%, respectively. The char and TG-FTIR data of EP3 reveal that it has a more compact structure, good thermal stability, and produce fewer toxic gases and smoke. Reduction of GO could inhibit the degradation of EP, and iron catalyzes the formation of carbonaceous char on the surface. Thus, the thermal stability and flame retardancy of EP are improved significantly. This study provides a suitable way to prepare graphene/EP composites that contain iron catalyst and can be extended to the industrial manufacture of flame retardant polymer composites. Keywords: iron powder; epoxy resin; graphene oxide; flame retardant; thermal stability

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.

Preparation of dual-functionalized graphene oxide for the improvement of the thermal stability and flame-retardant properties of polysiloxane foam

2018 ◽  
Vol 42 (16) ◽  
pp. 13873-13883 ◽  
Author(s):  
Tianlu Xu ◽  
Chunling Zhang ◽  
Peihong Li ◽  
Xueyan Dai ◽  
Lijie Qu ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Graphene Oxide ◽  
Flame Retardant ◽  
Oxygen Index ◽  
Functionalized Graphene ◽  
Foam Material ◽  
Functionalized Graphene Oxide ◽  
Limiting Oxygen Index ◽  
Flame Retardant Properties ◽  
Combustible Materials

Polysiloxane foam (PSF) is a foam material with outstanding performance. However, the limiting oxygen index (LOI) of pure PSF is only 22.0 vol%, which can be attributed to combustible materials.

Sign in / Sign up

Export Citation Format

Share Document