Synthesis of LDHs using red mud and bittern and its influence on the flame retardant properties of EVA/LDHs composites

2019 ◽  
Vol 28 (1) ◽  
pp. 14-25
Author(s):  
Long Li ◽  
Yi Qian ◽  
Haiming Zhang ◽  
Haoyue Han ◽  
Peng Qiao
Keyword(s):  
Flame Retardant ◽  
Red Mud ◽  
Ethylene Vinyl Acetate ◽  
Utilization Rate ◽  
Infrared Spectrometry ◽  
Limiting Oxygen Index ◽  
Safety Issues ◽  
Cone Calorimeter Test ◽  
Flame Retardant Properties ◽  
Double Hydroxides

Red mud (RM) is one kind of basic solid waste produced from aluminum industry. RM is usually stored by the method of land stockpiling, which has caused serious environmental and safety issues. Bittern, a by-product of salt manufacture, is abundant in China. But the utilization rate is low, less than 20%. The disposal of waste bittern has become a challenge that attracts much attention in water industry. In this article, Mg/Al/Fe layered double hydroxides (Mg/Al/Fe-LDHs) were synthesized using the above two wastes by a coprecipitation method and characterized by X-ray diffraction (XRD) and scanning electron microscopy. The XRD results showed that LDHs were successfully synthesized. Then, the flame-retardant properties and thermal properties of Mg/Al/Fe-LDHs in ethylene vinyl acetate (EVA)/LDHs composites had been tested by cone calorimeter test (CCT), limiting oxygen index (LOI), smoke density test (SDT), and thermogravimetry–Fourier transform infrared spectrometry (TG-FTIR). The CCT results showed that the heat release rate (HRR) of the EVA/LDHs composites significantly decreased in comparison with that of pure EVA, and EVA2 sample showed the lowest peak value of HRR value of 204.59 kW m−2. The LOI results showed that EVA3 had a highest LOI value of 28.3% in all the samples. The SDT test indicated that Mg/Al/Fe-LDHs were beneficial to the smoke suppression performance of EVA composites. TG-IR results showed that EVA/LDHs composites had better thermal stability than EVA.

scholarly journals Preparation of LDHs Based on Bittern and Its Flame Retardant Properties in EVA/LDHs Composites

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Long Li ◽  
Yi Qian ◽  
Peng Qiao ◽  
Haoyue Han ◽  
Haiming Zhang
Keyword(s):  
Flame Retardant ◽  
Ethylene Vinyl Acetate ◽  
Utilization Rate ◽  
Infrared Spectrometry ◽  
X Ray Diffraction ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
Cone Calorimeter Test ◽  
Flame Retardant Properties ◽  
Double Hydroxides

Bittern, as a byproduct of salt manufacture, is abundant in China. The researches and developments for seawater bittern have mainly focused on the reuse of magnesium, calcium, lithium, and boron. However, the utilization rate is less than 20%. The large amount of unused bittern has become a challenge that attracts much attention in academic and industry areas. In this paper, three kinds of layered double hydroxides (LDHs) were synthesized from bittern using a coprecipitation method and characterized by X-ray diffraction (XRD). The XRD results showed that the three kinds of LDHs(MgAl-LDHs, MgFe-LDHs and MgAlFe-LDHs) were successfully synthesized. Then, the flame retardant properties and thermal properties of the three LDHs in ethylene vinyl acetate (EVA)/LDHs composites had been tested by cone calorimeter test (CCT), limiting oxygen index (LOI), smoke density test (SDT), and thermogravimetry-Fourier transform infrared spectrometry (TG-IR). The CCT results showed that the heat release rate (HRR) of all three kinds of EVA/LDHs composites significantly decreased compared with that of pure EVA, and the EVA/MgAl-LDHs composites had the lowest PHRR value of 222.65 kW/m2. The LOI results showed that EVA/MgAl-LDHs composites had the highest LOI value of 29.8%. The SDT results indicated that MgAl-LDHs were beneficial to smoke suppression. TG-IR results showed that EVA/MgAl-LDHs composites had a better thermal stability.

Flame-Retardant Properties of Ethylene-Vinyl Acetate/Layered Double Hydroxides Composites

2014 ◽  
Vol 1035 ◽  
pp. 67-73
Author(s):  
Chui Xuan Jia ◽  
Yi Qian ◽  
Xi Lei Chen
Keyword(s):  
Flame Retardant ◽  
Vinyl Acetate ◽  
Layered Double Hydroxides ◽  
Red Mud ◽  
Ethylene Vinyl Acetate ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cone Calorimeter Test ◽  
Flame Retardant Properties ◽  
Double Hydroxides

Mg-Al-Fe ternary layered double hydroxides (LDHs) were synthesized based on Red mud by a calcination-rehydration method, and characterized using X-ray diffraction (XRD). The flame-retardant properties of EVA/LDHs (EVA, ethylene-vinyl acetate) composites were studied via cone calorimeter test (CCT), smoke density test (SDT), and Thermogravimetric analysis (TGA). The CCTs data indicate that heat release rates (HRR) of EVA/LDHs composites decrease in comparison with that of EVA, EVA/Red mud, EVA/ATH and EVA/MH composites. The SDT results show that LDHs is helpful to smoke suppression. The TGA show that LDHs-containing EVA2 has higher thermal stability at high temperatures than the other samples.

scholarly journals Improving the flame retardancy of ethylene vinyl acetate composites by incorporating layered double hydroxides based on Bayer red mud

e-Polymers ◽  
2019 ◽  
Vol 19 (1) ◽  
pp. 129-140 ◽  
Author(s):  
Yi Qian ◽  
Kangjia Jiang ◽  
Long Li
Keyword(s):  
Vinyl Acetate ◽  
Flame Retardancy ◽  
Layered Double Hydroxides ◽  
Red Mud ◽  
Ethylene Vinyl Acetate ◽  
Precipitation Method ◽  
Infrared Spectrometry ◽  
Cone Calorimeter Test ◽  
Bayer Red Mud ◽  
Double Hydroxides

AbstractNowadays, reducing the hazards of bayer red mud (BRM) is an important research direction in the fields of environmental and safety. In this article, Mg/Al/Fe ternary layered double hydroxides (Mg/Al/Fe-LDHs) were synthesized successfully by a co-precipitation method based on introducing Mg2+ into the BRM suspension. The thermogravimetric analysis (TGA) results showed that the decomposition rate of LDHs is higher than that of BRM, which indicates that LDHs can absorb more heat than BRM during the decomposition process. Subsequently, BRM and LDHs were added into the ethylene vinyl acetate (EVA) to investigate its effects on reducing flammability of the composites. The cone calorimeter test (CCT) results demonstrated that 50 wt% LDH-B can make the peak value of HRR (PHRR) decrease from 1694.8 kW/m2 (EVA) to 199.2 kW/m2 (ELDH2). The smoke density test (SDT) results showed that the luminous flux of ELDH2 is nearly 95% at the end of test with a pilot flame, which is much higher than that of EVA and EBRM. The thermogravimetry-Fourier transform infrared spectrometry (TG-FTIR) results confirmed that LDHs can improve the thermal stability of composites and reduce the production of some toxic gases. Compared with BRM, the improved flame retardancy of Mg/Al/Fe-LDHs is ascribed to the introduction of Mg2+, which offering an enhanced catalytic carbonization capability, as well as the physical barrier effect of char residue layer catalyzed by the lamellar LDHs

scholarly journals Basalt Fiber Modified Ethylene Vinyl Acetate/Magnesium Hydroxide Composites with Balanced Flame Retardancy and Improved Mechanical Properties

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2107
Author(s):  
Dongwei Yao ◽  
Guangzhong Yin ◽  
Qingqing Bi ◽  
Xu Yin ◽  
Na Wang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Vinyl Acetate ◽  
Magnesium Hydroxide ◽  
Performance Enhancement ◽  
Basalt Fiber ◽  
Ethylene Vinyl Acetate ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Flame Retardant Properties

In this study, we selected basalt fiber (BF) as a functional filler to improve the mechanical properties of ethylene vinyl acetate (EVA)-based flame retardant materials. Firstly, BF was modified by grafting γ-aminopropyl triethoxysilane (KH550). Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscope (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to comprehensively prove the successful modification of the BF surface. Subsequently, the modified BF was introduced into the EVA/magnesium hydroxide (MH) composites by melt blending. The limiting oxygen index (LOI), UL-94, cone calorimeter test, tensile test, and non-notched impact test were utilized to characterize both the flame retardant properties and mechanical properties of the EVA/MH composites. It was found that the mechanical properties were significantly enhanced without reducing the flame retardant properties of the EVA/MH composites. Notably, the surface treatment with silane is a simple and low-cost method for BF surface modification and the pathway designed in this study can be both practical and effective for polymer performance enhancement.

Phosphine oxide for reducing flammability of ethylene-vinyl-acetate copolymer

e-Polymers ◽  
2021 ◽  
Vol 21 (1) ◽  
pp. 299-308
Author(s):  
Jiawei Jiang ◽  
Ruifeng Guo ◽  
Haifeng Shen ◽  
Shiya Ran
Keyword(s):  
Flame Retardant ◽  
Vinyl Acetate ◽  
Ethylene Vinyl Acetate ◽  
Infrared Spectrometry ◽  
Limiting Oxygen Index ◽  
Gaseous Products ◽  
H Nmr ◽  
Highly Active ◽  
Cone Calorimeter Test ◽  
Combustion Behaviors

Abstract In this work, a phosphorous-containing flame retardant, phenylphosphonate-based compound (EHPP), is synthesized by alcoholysis and hydrazinolysis of phenylphosphonic dichloride, which is subsequently introduced to ethylene-vinyl-acetate (EVA) copolymer to improve its flame retardant performance. The resultant compound was characterized by Fourier transform infrared (FTIR), 1H NMR, 13C NMR, and 31P NMR. The influence of the EHPP on the combustion behaviors of EVA is studied by limiting oxygen index (LOI), UL-94, and cone calorimeter test. The results show that 1 wt% EHPP can reduce peak heat release rate (PHRR) by 40%. Moreover, 2 wt% EHPP can increase LOI from 20.5% to 25.5%. Thermogravimetric analysis/infrared spectrometry (TGA-FTIR) was used to detect the gaseous products of EVA/EHPP to study the gaseous-phase flame retardant mechanism. The EHPP released phosphorus-containing radicals to capture highly active free radicals to improve the flame retardancy of EVA.

Novel flame retardancy effect of phenethyl-bridged DOPO derivative on epoxy resin

2017 ◽  
Vol 30 (6) ◽  
pp. 667-676 ◽  
Author(s):  
Wei Yan ◽  
Jie Yu ◽  
Mingqiu Zhang ◽  
Lijuan Long ◽  
Tao Wang ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Visual Observation ◽  
Gas Chromatography Mass Spectrometry ◽  
Infrared Spectrometry ◽  
Pyrolysis Gas ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Potential Applications ◽  
Flame Retardant Properties ◽  
Oxide Derivative

A series of flame-retardant epoxy resins (EPs) containing either phenethyl-bridged 9 or 10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide derivative (bisDOPO) were prepared. The flame-retardant properties of bisDOPO on EP composites were characterized by the limiting oxygen index (LOI), the UL-94 vertical burning, and the cone calorimeter test (CCT).The LOI of the EP/bisDOPO composites increased from 21.8% to 38.0%, and the hybrids with the 10 wt% bisDOPO obtained a V-0 rating in the UL94 vertical burning test. The char residue following the CCT showed intumescent structures with continuous and compact surfaces that can effectively suppress the spread of the flame and extinguish the fire. This was confirmed through both visual observation and scanning electron microscopy (SEM) measurements. The flame-retardant mechanism was studied by Fourier transform infrared spectroscope (FTIR), thermogravimetric analysis/infrared spectrometry, SEM/energy-dispersive X-ray, and pyrolysis-gas chromatography/mass spectrometry. Overall, bisDOPO was an effective flame retardant with potential applications within EP.

Flame Retardance and Thermal Decomposition of EVA Composites Containing Melamine Phosphate and Dipentaerythritol

2011 ◽  
Vol 284-286 ◽  
pp. 1831-1835
Author(s):  
Zheng Zhou Wang ◽  
Lin Liu ◽  
Gan Xin Jie ◽  
Ping Kai Jiang
Keyword(s):  
Thermal Decomposition ◽  
Flame Retardant ◽  
Flame Retardants ◽  
Ethylene Vinyl Acetate ◽  
Limiting Oxygen Index ◽  
Melamine Phosphate ◽  
Suitable Amount ◽  
Flame Retarded ◽  
Flame Retardant Properties ◽  
Acetate Copolymer

Flame retarded ethylene-vinyl acetate copolymer (EVA) was prepared in a melt process containing melamine phosphate (MP), or MP in combination with dipentaerythritol (DPER) as flame retardants. The influence of MP and MP/DPER on flame retardant properties of EVA was investigated by limiting oxygen index (LOI) and UL 94 test. Thermal decomposition of the flame retardants and flame retarded EVA composites was studied by the thermogravimetric analysis. The results show that MP used alone in EVA does not exerts good flame retardancy, even at a loading of 50wt%. It is found that the flame retardant properties of the EVA/MP/DPER composites is greatly improved when a suitable amount of MP substituted by DPER. Moreover, mechanical properties of the EVA composites were studied.

scholarly journals Enhanced Flame Retardancy in Ethylene–Vinyl Acetate Copolymer/Magnesium Hydroxide/Polycarbosilane Blends

Polymers ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 36
Author(s):  
Tiefeng Zhang ◽  
Chunfeng Wang ◽  
Yongliang Wang ◽  
Lijun Qian ◽  
Zhidong Han
Keyword(s):  
Synergistic Effect ◽  
Flame Retardant ◽  
Vinyl Acetate ◽  
Magnesium Hydroxide ◽  
Ethylene Vinyl Acetate ◽  
Infrared Spectrometry ◽  
Limiting Oxygen Index ◽  
Blending Method ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

A polymer ceramic precursor material—polycarbosilane (PCS)—was used as a synergistic additive with magnesium hydroxide (MH) in flame-retardant ethylene–vinyl acetate copolymer (EVA) composites via the melt-blending method. The flame-retardant properties of EVA/MH/PCS were evaluated by the limiting oxygen index (LOI) and a cone calorimeter (CONE). The results revealed a dramatic synergistic effect between PCS and MH, showing a 114% increase in the LOI value and a 46% decrease in the peak heat release rate (pHRR) with the addition of 2 wt.% PCS to the EVA/MH composite. Further study of the residual char by scanning electron microscopy (SEM) proved that a cohesive and compact char formed due to the ceramization of PCS and close packing of spherical magnesium oxide particles. Thermogravimetric analysis coupled with Fourier-transform infrared spectrometry (TG–FTIR) and pyrolysis–gas chromatography coupled with mass spectrometry (Py–GC/MS) were applied to investigate the flame-retardant mechanism of EVA/MH/PCS. The synergistic effect between PCS and MH exerted an impact on the thermal degradation products of EVA/MH/PCS, and acetic products were inhibited in the gas phase.

Synergistic flame retardant effect between nano-silicon dioxide and layered double hydroxides in ethylene vinyl acetate composites

2017 ◽  
Vol 31 (10) ◽  
pp. 1295-1309 ◽  
Author(s):  
Yi Qian ◽  
Shaojie Zhou ◽  
Xilei Chen
Keyword(s):  
Silicon Dioxide ◽  
Heat Release ◽  
Flame Retardant ◽  
Vinyl Acetate ◽  
Layered Double Hydroxides ◽  
Ethylene Vinyl Acetate ◽  
Limiting Oxygen Index ◽  
Nano Silicon ◽  
Synergistic Flame Retardant ◽  
Double Hydroxides

Layered double hydroxides (LDHs) were synthesized by a coprecipitation method. The synergistic flame retardant effect of nano-silicon dioxide (nano-SiO2) on ethylene vinyl acetate (EVA)/LDHs composites was studied using limiting oxygen index (LOI), cone calorimeter test (CCT), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Results showed that the LOI values of the EVA/LDHs/nano-SiO2 composites were basically higher than that of the EVA/LDHs composite, and the EVA composite with 48% LDHs and 2% nano-SiO2 reached an LOI value of up to 31.2%. The CCT results indicate that the addition of nano-SiO2 greatly reduced the heat release rate, total heat release, mass loss, smoke production rate, total smoke release, and smoke factor. The morphology and structures of residues investigated by SEM gave positive evidence that char layers formed from the EVA/LDHs/nano-SiO2 composites were improved. The TGA data showed that the EVA/LDHs/nano-SiO2 composites show a higher thermal stability than the EVA/LDHs composites.

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