scholarly journals Study on the Synergies of Nanoclay and MWCNTs to the Flame Retardant and Mechanical Properties of Epoxy Nanocomposites

2021 ◽  
Vol 2021 ◽  
pp. 1-8
Author(s):  
Tuan Anh Nguyen

Modern flame retardants are organic compounds containing halogen or phosphorus groups and are not always well dispersed in polymers. Thus, by using a small amount of nanoclay and multiwalled carbon nanotubes (MWCNTs), they can significantly reduce the number of conventional flame retardant additives, making the material with optimal flame retardant properties. Conventional flame retardants always have some negative effects on the mechanical properties of the polymer substrate, so by using nanoclay and MWCNTs, those adverse effects can be minimized and overcome. In this work, in order to improve the mechanical properties and flame retardant of nanocomposite materials, nanoclay I.30E and MWCNTs are mixed into epoxy, with the selected percentage of 2% and 0.02% by weight, respectively, stirring mechanically for 7, 8, and 9 hours at 3000 rpm at 80°C, then performing ultrasonic vibration for 6 hours at 65°C.

2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Tuan Anh Nguyen ◽  
Thi Thu Trang Bui

In this study, nanoclay I.30E and multiwalled carbon nanotubes (MWCNT) were hybridized with graphene oxide (GO) on Epikote 240 epoxy resin. Research results show that the hybridization between 0.5 wt.% GO with 1 or 3 wt.% nanoclay and 0.05 wt.% MWCNT has better mechanical properties and flame-retardant properties than the component materials. The combination of epoxy nanocomposite materials with flame-retardant additives such as nanoclay, MWCNT, and GO leads to improving flame-retardant and mechanical properties. Flame-retardant materials have no environmental problems and are nontoxic. Therefore, the flame-retardant additives studied in this work have great potential to become one of the promising flame-retardant hybrid materials. The study also showed that the result of the combination, the hybridization between the three components (nanoclay, MWCNT, and GO) synergized the mechanisms of fire resistance, creating insulating barriers, preventing objects from entering material exposed to heat and oxygen in the air.


2015 ◽  
Vol 30 (6) ◽  
pp. 816-826 ◽  
Author(s):  
Yiren Huang ◽  
Jianwei Yang ◽  
Zhengzhou Wang

Flame-retardant properties of ammonium polyphosphate (APP) and its two microcapsules, APP with a shell of melamine–formaldehyde (MF) resin (MFAPP) and APP with a shell of epoxy resin (EPAPP), were studied in styrene–butadiene–styrene (SBS). The results indicate that APP after the microencapsulation leads to an increase in limiting oxygen index in SBS compared with APP. When dipentaerythritol is incorporated into the SBS composites containing the APP microcapsules, a further improvement in flame retardancy of the composites is observed. The microencapsulation does not result in much improvement of mechanical properties. Moreover, the effect of a compatibilizer (SBS grafted with maleic anhydride) on flame-retardant and mechanical properties of SBS/APP composites was investigated.


2019 ◽  
Vol 2019 ◽  
pp. 1-25 ◽  
Author(s):  
Shaolin Lu ◽  
Wei Hong ◽  
Xudong Chen

Polymer materials are ubiquitous in daily life. While polymers are often convenient and helpful, their properties often obscure the fire hazards they may pose. Therefore, it is of great significance in terms of safety to study the flame retardant properties of polymers while still maintaining their optimal performance. Current literature shows that although traditional flame retardants can satisfy the requirements of polymer flame retardancy, due to increases in product requirements in industry, including requirements for durability, mechanical properties, and environmental friendliness, it is imperative to develop a new generation of flame retardants. In recent years, the preparation of modified two-dimensional nanomaterials as flame retardants has attracted wide attention in the field. Due to their unique layered structures, two-dimensional nanomaterials can generally improve the mechanical properties of polymers via uniform dispersion, and they can form effective physical barriers in a matrix to improve the thermal stability of polymers. For polymer applications in specialized fields, different two-dimensional nanomaterials have potential conductivity, high thermal conductivity, catalytic activity, and antiultraviolet abilities, which can meet the flame retardant requirements of polymers and allow their use in specific applications. In this review, the current research status of two-dimensional nanomaterials as flame retardants is discussed, as well as a mechanism of how they can be applied for reducing the flammability of polymers.


Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1956 ◽  
Author(s):  
Heng Zhang ◽  
Junliang Lu ◽  
Hongyan Yang ◽  
Jinyan Lang ◽  
Heng Yang

Three metal salts of dicyclohexyl hypophosphite, namely dicyclohexyl aluminum hypophosphite (ADCP), dicyclohexyl magnesium hypophosphite (MDCP), and dicyclohexyl zinc hypophosphite (ZDCP), were synthesized. These flame retardants were subjected to thermogravimetric analysis, and the results showed that ADCP and ZDCP had higher thermal stabilities than MDCP. They were then separately mixed with polyamide 66 (PA66)to prepare composite materials, of which the combustion properties were determined by the limiting oxygen index method and horizontal/vertical burning experiments. The mechanical properties of the materials were further evaluated using an electronic universal testing machine. The results showed that all the three flame retardants exerted a flame-retardant effect on PA66, but the flame-retardant effect of MDCP was inferior to those of ADCP and ZDCP. All the composites also showed similar mechanical properties. Among the three flame retardants, ADCP had the best overall performance for raw materials, showing good flame-retardant properties while maintaining the mechanical properties of the raw materials. The optimal dosage of ADCP was 15 wt %, at which a V-0 rating in the vertical burning test (UL 94 test) can be obtained.


2017 ◽  
Vol 30 (9) ◽  
pp. 1036-1047
Author(s):  
Baoxia Xue ◽  
Yun Peng ◽  
Yinghao Song ◽  
Jie Bai ◽  
Mei Niu ◽  
...  

Novel flame-retardant phosphorylated chitosan-multiwalled carbon nanotubes (PCS-MWCNTs) were obtained by the loading of PCS on the surface of MWCNTs by a chemical deposition cross-linking method. A series of polyethylene terephthalate (PET) composites were prepared by melt compounding with MWCNTs or PCS-MWCNTs to investigate the flame-retardant properties. Field-emission scanning electron microscopy, transmission electron microscopy, and Fourier transform infrared (FTIR) spectrometry were employed to characterize the morphology, chemical structure, and functionalization effect of MWCNTs. The coating degree and thermal stability of PCS-MWCNTs were investigated by thermogravimetric analysis (TGA). Thermal decomposition products after TGA and flame-retardant properties of PET composites were characterized by FTIR and CONE measurements, respectively. The results indicated that PCS is loaded on the MWCNT surface. Modified PCS-MWCNTs exhibited better dispersion and efficient flame retardancy. TGA data indicated that PCS-MWCNTs can enhance the onset temperature of PET and increase the amount of the char residues. The char residue with 1 wt% PCS-MWCNTs/PET increased from 12.62% (pure PET) to 15.46%. The analysis of the decomposition products and morphology of the char residue indicated that PCS-MWCNTs not only retain the effect of alternating couplet carbon (C) and physical barrier by MWCNTs, but also form P–C compounds, improving the flame retardancy of PET. CONE tests demonstrated that the PCS-MWCNTs lead to the efficient decrease in the flammability parameters, such as the heat release rate (HRR), total release heat rate (THR), total smoke production (TSP), mean mass loss rate (MMLR), and the total combustion time. The peak HRR value decreased from 513.22 kW m−2 to 341 kW m−2. The THR, TSP, and MMLR values decreased by 20.38 MJ m−2, 1.1 m2, and 1.32 g s−1, respectively. The total combustion time decreased by 98 s, from 388 s to 290 s, indicating that PCS-MWCNTs extinguish fire.


RSC Advances ◽  
2021 ◽  
Vol 11 (49) ◽  
pp. 30860-30872
Author(s):  
Qirui Gong ◽  
Liangyu Qin ◽  
Liangmin Yang ◽  
Keke Liang ◽  
Niangui Wang

A vegetable oil-based polyurethane rigid foam containing a phosphorus–nitrogen dualflame retardant system was prepared, and the foam exhibited not only excellent flame retardant properties but also good mechanical properties.


2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Tuan Anh Nguyen ◽  
Thi Thu Trang Bui

Carbon-based fillers have attracted a lot of interest in polymer composites because of their ability to alter beneficial properties at low filler concentrations, good surface bonding with polymers, availability in different forms, etc. Carbon-based materials (such as fullerene, CNTs, graphene, and graphite) have been studied as fillers with enhanced fire resistance to epoxy resins. In order to reduce the flammability and improve the thermal stability of epoxy resin-based nanocomposite materials, which can be achieved by a simultaneous combination of graphene oxide and multiwall carbon nanotubes, the graphite oxide (GO) epoxy nanomaterial was developed by 1% wt.% GO combined with 0.02 wand 0.04 wt.% MWCNT. The homogeneous dispersion of GO and MWCNTs in epoxy resins is supported by ultrasonic vibrations. The results showed that when nanocomposite materials were present at the same time MWCNTs and GO, their mechanical properties and fire resistance were significantly improved. Nanomaterials are characterized by FT-IR spectroscopy and SEM imaging, mechanical strength, and flame retardant properties (LOI, UL94).


2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Tuan Anh Nguyen ◽  
Quang Tung Nguyen

In this study, fly ash (FA) and multiwalled carbon nanotubes (MWCNTs) were used to make environmentally friendly nanocomposites, which have high fire retardant properties and high mechanical properties. Industrial waste such as fly ash has become a major concern during the treatment of environmental pollution. MWCNTs were used in this experiment to enhance the flame retardant properties and mechanical properties of materials with fly ash additives. MWCNTs content (0.03, 0.04, and 0.05 wt.%) and fly ash content (30, 40, and 50 wt.%) were studied for three different levels. The flame retardancy of the material is significantly improved by the addition of fly ash/MWCNTs at different rates, especially at 0.04 wt. % MWCNTs and 40 wt. % fly ash with LOI at 26.8%. Regarding mechanical properties, tensile strength increases as fly ash/MWCNTs increase, up to a critical point. On the other hand, the compressive strength of composite increases continuously as fly ash/MWCNTs increase. Scanning electron microscopy (SEM) was used to observe the morphology of fly ash and MWCNTs as well as its distribution in the matrix. This will help analyze the influence of the effectiveness of the combination of fly ash and MWCNTs to the flame retardancy and mechanical properties of fly ash/MWCNTs/epoxy nanocomposites.


2018 ◽  
Vol 22 (7) ◽  
pp. 2408-2420
Author(s):  
Yu-Chun Chuang ◽  
Limin Bao ◽  
Ching-Wen Lou ◽  
Jia-Horng Lin

In this study, three differently composed polyurethane (PU) composites are developed and then compared with the pure PU foam in terms of combustion resistance and mechanical properties using the compression test, the drop-weight impact test, the horizontal burning test, and the sound absorption test. Flame-retardant fabric (FRF)-PU is composed of PU foam that is enclosed with two cover sheets of FRFs. FR-PU10 is composed of PU foam that contains 10 wt% of flame-retardant agents. FRF-PU10 is composed of PU foam containing 10 wt% of flame-retardant agents and enclosed by two covers sheets of FRFs. Based on the test results, both FR-PU10 and FRF-PU10 are structurally stabilized and have good combustion resistance. The sample using FRFs as cover sheet had the same combustion resistance property and better compression resistance as the sample using flame-retardant agent. The carbonized layer extinguishes the alighted samples and stops the fire spread right after they are out of the source of fire, suggesting the FRF-PU10 is flame retardant. In addition, FRF-PU10 is easier to process and healthier because of the low use of flame retardants. Therefore, in this study, we proposed PU foam composites have good mechanical and flame-retardant properties and are a suitable candidate for productions of vehicles, plants, construction, and staple merchandises.


2012 ◽  
Vol 2 (6) ◽  
pp. 166-168 ◽  
Author(s):  
Dr.T.Ch.Madhavi Dr.T.Ch.Madhavi ◽  
◽  
Pavithra.P Pavithra.P ◽  
Sushmita Baban Singh Sushmita Baban Singh ◽  
S.B.Vamsi Raj S.B.Vamsi Raj ◽  
...  

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