scholarly journals Preparation of Intercalated Organic Montmorillonite DOPO-MMT by Melting Method and Its Effect on Flame Retardancy to Epoxy Resin

Polymers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 3496
Author(s):  
Junming Geng ◽  
Jianyu Qin ◽  
Jiyu He

An intercalated organic montmorillonite DOPO-MMT was prepared through the melting method using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as a modifier. Epoxy resin (EP) composites were prepared with DOPO-MMT, DOPO, MMT, and the physical mixtures of DOPO+MMT as flame retardants. The microstructure of the flame retardants and EP samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The flame retardant properties, thermal stability, and residual char structure of the EPs were studied by the limited oxygen index (LOI) test, the UL-94 vertical burning test, thermogravimetric analysis (TGA), the differential scanning calorimeter (DSC) test, the cone calorimeter (CONE) test as well as other characterization methods. The results showed that the intercalated organic montmorillonite DOPO-MMT can be successfully prepared by the melting method and that the MMT is evenly dispersed in the EP/DOPO-MMT composite in the form of nanosheets. The EP/DOPO-MMT nanocomposites showed the optimal flame retardancy (LOI, UL-94, PHRR, etc.) among the EPs with DOPO, MMT, and the physical mixture of DOPO+MMT. The flame-retardant grade of the material reached V-0.

2015 ◽  
Vol 35 (2) ◽  
pp. 113-117 ◽  
Author(s):  
Qilei Wang

Abstract In order to obtain flame retardants with good heat resistance, retardant properties and affinity, magnesium hydroxide (MH)/siloxane nanocomposite flame retardants were prepared by the hydrothermal and hypergravity method. The MH and MH/siloxane particles were characterized and analyzed by transmission electron microscopy (TEM), Brunner-Emment-Teller (BET) measurements, thermogravimetric analysis (TGA), etc. The results show that the stability of as-prepared MH/siloxane nanocomposite flame retardants is superior to MH particles prepared by other prepared methods, and the agglomeration is significantly reduced. The specific area of the composite particles was reduced, and the affinity and thermal stability were effectively improved. As a kind of filler for polymer, the MH/siloxane nanocomposite could help to improve the reinforcement of the polymer, and the heat resistant and flame retardant properties, which provide the foundation for further application of this nanocomposite as a flame retardant.


10.6036/10327 ◽  
2022 ◽  
Vol 97 (1) ◽  
pp. 98-103
Author(s):  
XIAN WANG ◽  
JINLONG ZHUO ◽  
TIANQING XING ◽  
Xingran Wang

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


2012 ◽  
Vol 15 (3) ◽  
pp. 73-79
Author(s):  
Quy Thi Dong Hoang ◽  
Cuong Ngoc Hoang ◽  
Anh Huynh Tram Pham ◽  
Vien Tri Thiem ◽  
Huong Ngoc Nhu Nguyen ◽  
...  

In order to improve fire performance of polymeric materials, phosphorus flame retardants (FRs) were studied in an attempt to obtain UL-94 ratings for materials based on unsaturated polyester. The fire behaviors and thermal stability properties were evaluated using UL-94 vertical test and thermogravimetric analysis (TGA). The UL-94 test results show that V-1 rating is achieved. TGA and UL-94 results concluded that phosphorus FRs employed in this study works on both vapor phase and condensed phase, but the vapour phase is dominant mode of action. These suggested that the addition of FRs probably does affect on the char layer formed during combustion behavior and increase the flame retardant properties in the case of condensed phase mode of action. The efficiency of flame retardant of phosphorus also highly depends upon the phosphorus moieties generated during the decomposition which further converted to radical capturing species, and consequently quenching the flame in the case of gas phase mode of action. These FRs can be promising candidates that replace the halogen-based.


2017 ◽  
Vol 30 (2) ◽  
pp. 202-210 ◽  
Author(s):  
Rasool Kheyrabadi ◽  
Hossein Rahmani ◽  
S Heydar Mahmoudi Najafi

Flame-retardant halogen-free epoxy resin, containing phosphorus and nitrogen atoms in the main chain, was synthesized through the curing of tris(3-(bis(oxiran-2-ylmethyl)amino)phenyl)phosphine oxide (HGE, hexaglycidyl epoxy monomer), starting from tris(3-aminophenyl) phosphine oxide (TAPO) and epichlorohydrin. The molecular structure of HGE with molecular weight 660 was confirmed using Fourier transform infrared, nuclear magnetic resonance, and liquid chromatography–mass spectrometry techniques. Epoxy equivalent weight determined by titration method was 120. The thermal curing behavior of the HGE/TAPO was investigated by differential scanning calorimetry. An intense exotherm due to curing reaction was observed in the temperature range from 123°C to 215°C. The HGE cured with TAPO, 4,4′-diaminodiphenylsulfone (DDS), and 1,5-diaminonaphthalene (DAN) and the thermal behaviors were studied by thermogravimetric analysis. The flame retardancy properties of the HGE/TAPO, DDS, and DAN were evaluated by vertical burning test (UL-94 V). The high performance cured epoxy resins showed high thermal stability and UL-94 V-0 flame retardancy rating.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
F. I. Beltrán-Ramírez ◽  
L. F. Ramos-deValle ◽  
E. Ramírez-Vargas ◽  
S. Sánchez-Valdes ◽  
A. B. Espinoza-Martínez ◽  
...  

The effect of nanometric magnesium and aluminum hydroxides on the flame retardancy of high density polyethylene was studied. Additionally, the effect of maleic anhydride grafted polyethylene (PEgMA) and methyl acrylate grafted polyethylene (EMA) compatibilizers, on the tensile properties, was also studied. Morphological characterization of nanocomposites was carried out by means of scanning transmission electron microscopy (STEM). Flame retardant properties of nanocomposites were evaluated by the UL-94 horizontal and vertical tests as well as by cone calorimeter tests. Thermal degradation behavior was analyzed with a thermogravimetric analyzer (TGA). Tensile tests were carried out according to ASTM D 638-03 in an Instron 4301 tensile testing machine. From STEM images, a good dispersion of flame retardants (MH and ATH) in the polymer matrix was observed, which was reflected in the flame retardant properties. Results showed that the combination of nanometric MH and ATH produced excellent flame retardant properties, achieving a classification of V0 in the UL-94-V test and producing the lowest peak of heat release rate (PHRR) and the lowest total heat released (THR) in the cone calorimeter test. Finally, the addition of compatibilizer, especially PEgMA, resulted in much better tensile properties as compared to the noncompatibilized composition, maintaining the flame retardant properties.


2016 ◽  
Vol 29 (5) ◽  
pp. 513-523 ◽  
Author(s):  
Tie Zhang ◽  
Weishi Liu ◽  
Meixiao Wang ◽  
Ping Liu ◽  
Yonghong Pan ◽  
...  

With the aim of developing a novel organic flame retardant, an organic boronic acid derivative containing a triazine ring (2,4,6-tris(4-boronic-2-thiophene)-1,3,5-triazine (3TT-3BA)) was synthesized. The thermal properties of 3TT-3BA and its corresponding intermediate products were investigated by thermogravimetric analysis. The results show that 3TT-3BA has a high char yield (56.9%). The flame retardant properties of epoxy resin (EP) with 3TT-3BA were investigated by cone calorimeter, limiting oxygen index (LOI) test, and vertical burning test (UL 94). The LOI of EP with 20% 3TT-3BA is 31.2% and the UL 94 V-0 rating is achieved for EP with 20% 3TT-3BA. The flame retardant mechanism of 3TT-3BA in EP was investigated using TGA–Fourier transform infrared spectroscopy and scanning electron microscopy.


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.


Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1181
Author(s):  
Noha Ramadan ◽  
Mohamed Taha ◽  
Angela Daniela La Rosa ◽  
Ahmed Elsabbagh

Epoxy and unsaturated polyester resins are the most used thermosetting polymers. They are commonly used in electronics, construction, marine, automotive and aircraft industries. Moreover, reinforcing both epoxy and unsaturated polyester resins with carbon or glass fibre in a fabric form has enabled them to be used in high-performance applications. However, their organic nature as any other polymeric materials made them highly flammable materials. Enhancing the flame retardancy performance of thermosetting polymers and their composites can be improved by the addition of flame-retardant materials, but this comes at the expense of their mechanical properties. In this regard, a comprehensive review on the recent research articles that studied the flame retardancy of epoxy resin, unsaturated polyester resin and their composites were covered. Flame retardancy performance of different flame retardant/polymer systems was evaluated in terms of Flame Retardancy index (FRI) that was calculated based on the data extracted from the cone calorimeter test. Furthermore, flame retardant selection charts that relate between the flame retardancy level with mechanical properties in the aspects of tensile and flexural strength were presented. This review paper is also dedicated to providing the reader with a brief overview on the combustion mechanism of polymeric materials, their flammability behaviour and the commonly used flammability testing techniques and the mechanism of action of flame retardants.


2018 ◽  
Vol 31 (8) ◽  
pp. 885-892 ◽  
Author(s):  
Yanan Yan ◽  
Bing Liang

A novel flame-retardant additive, 6,6′,6″-((1,3,5-triazine-2,4,6 triyl) tris (azanediyl)) tris (dibenzo[c,e][1,2]oxaphosphinine 6-oxide) (DOPO-M), was synthesized from melamine and 9,10-dihy-dro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO). The structure of DOPO-M was characterized by Fourier transform infrared (FTIR) spectroscopy, proton (1H) and phosphorous (31P) nuclear magnetic resonance (NMR) spectroscopies, and electrospray ionization mass spectroscopy (ESI-MS). DOPO-M was blended into epoxy resin (EP) to prepare flame-retardant EPs. The flame-retardant and thermal properties of EPs cured with triethylenetetramine (TETA) were investigated by thermogravimetric analysis (TGA), the UL-94 test, and the limiting oxygen index (LOI) test. The results revealed that the epoxy thermosets exhibited excellent flame retardancy and passed the V-0 rating of the UL-94 test with an LOI of 29.3% when the phosphorus content was 2.57 wt%. The scanning electron microscopy (SEM) results showed that DOPO-M in the EP/TETA system obviously accelerated the formation of a stronger, phosphorus-rich sealing char layer to improve the flame-retardant properties of the matrix during combustion.


Materials ◽  
2020 ◽  
Vol 13 (17) ◽  
pp. 3656
Author(s):  
Hangfeng Yang ◽  
Hangbo Yue ◽  
Xi Zhao ◽  
Minzimo Song ◽  
Jianwei Guo ◽  
...  

A novel halogen-free flame retardant containing sulfonamide, 1,3,5,7-tetrakis (phenyl-4-sulfonamide) adamantane (FRSN) was synthesized and used for improving the flame retardancy of largely used polycarbonate (PC). The flame-retardant properties of the composites with incorporation of varied amounts of FRSN were analyzed by techniques including limited oxygen index, UL 94 vertical burning, and cone calorimeter tests. The new FR system with sulfur and nitrogen elements showed effective improvements in PC’s flame retardancy: the LOI value of the modified PC increased significantly, smoke emission suppressed, and UL 94 V-0 achieved. Typically, the composite with only 0.08 wt% of FRSN added (an ultralow content) can increase the limiting oxygen index (LOI) value to 33.7% and classified as UL 94 V-0 rating. Furthermore, the mechanical properties and SEM morphology indicated that the FRSN has very good compatibility with PC matrix, which, in turn, is beneficial to the property enhancement. Finally, the analysis of sample residues after burning tests showed that a high portion of char was formed, contributing to the PC burning protection. This synthesized flame retardant provides a new way of improving PC’s flame retardancy and its mechanical property.


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