scholarly journals Effects of Combining Graphene Nanoplatelet and Phosphorous Flame Retardant as Additives on Mechanical Properties and Flame Retardancy of Epoxy Nanocomposite

Polymers ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 2349
Author(s):  
Woranan Netkueakul ◽  
Beatrice Fischer ◽  
Christian Walder ◽  
Frank Nüesch ◽  
Marcel Rees ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Crosslinking Density ◽  
Milling Process ◽  
Structure Property ◽  
Cone Calorimetry ◽  
Graphene Nanoplatelet ◽  
Phosphorous Flame Retardant

The effects of combining 0.1–5 wt % graphene nanoplatelet (GNP) and 3–30 wt % phosphorous flame retardant, 9,10- dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) as fillers in epoxy polymer on the mechanical, flame retardancy, and electrical properties of the epoxy nanocomposites was investigated. GNP was homogeneously dispersed into the epoxy matrix using a solvent-free three-roll milling process, while DOPO was incorporated into the epoxy resin by mechanical stirring at elevated temperature. The incorporation of DOPO reduced the crosslinking density of the epoxy resin. When using polyetheramine as a hardener, the structural rigidity effect of DOPO overshadowed the crosslinking effect and governed the flexural moduli of epoxy/DOPO resins. The flexural moduli of the nanocomposites were improved by adding GNP up to 5 wt % and DOPO up to 30 wt %, whereas the flexural strengths deteriorated when the GNP and DOPO loading were higher than 1 wt % and 10 wt %, respectively. Limited by the adverse effects on mechanical property, the loading combinations of GNP and DOPO within the range of 0–1 wt % and 0–10 wt %, respectively, in epoxy resin were further studied. Flame retardancy index (FRI), which depended on three parameters obtained from cone calorimetry, was considered to evaluate the flame retardancy of the epoxy composites. DOPO showed better performance than GNP as the flame retardant additive, while combining DOPO and GNP could further improve FRI to some extent. With the combination of 0.5 wt % GNP and 10 wt % DOPO, improvement in both mechanical properties and flame retardant efficiency of the nanocomposite was observed. Such a combination did not affect the electrical conductivity of the nanocomposites since the percolation threshold was at 1.6 wt % GNP. Our results enhance the understanding of the structure–property relationship of additive-filled epoxy resin composites and serve as a property constraining guidance for the composite manufacturing.

scholarly journals Suppression of Smoldering of Calcium Alginate Flame-Retardant Paper by Flame-Retardant Polyamide-66

Polymers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 430
Author(s):  
Kai Xu ◽  
Xing Tian ◽  
Ying Cao ◽  
Yaqi He ◽  
Yanzhi Xia ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Calcium Alginate ◽  
Ignition Time ◽  
Carbon Layer ◽  
Polyamide 66 ◽  
Cone Calorimetry ◽  
Air Atmosphere ◽  
Phosphorous Flame Retardant ◽  
Composite Paper

Calcium alginate (Ca-Alg) fibers are renewable fibers obtained from the ocean with essential flame retardancy, which have recently been applied as components of flame-retardant paper. However, the application of Ca-Alg fibers is limited because of their tendency to smolder. Therefore, composites papers were fabricated by blending using flame-retardant polyamide-66 (FR-PA), with a 5 wt% content of phosphorous flame retardant, which will form molten carbon during combustion. When the FR-PA content is 30% of the composite paper, FR-PA forms a compact carbon layer on the surface of the Ca-Alg fibers during combustion, which isolates the mass/heat transfer and effectively suppresses the smoldering of Ca-Alg. This consists of a condensed flame retardant mechanism. Furthermore, the combustion and thermal degradation behavior of paper were analyzed by cone calorimetry (CONE), TG and TG-IR. Ca-Alg in the composite paper decomposed and released CO2 before ignition, which delayed the ignition time. Simultaneously, the FR-PA contained in the composite paper effectively inhibited the combustion of volatile combustibles in the gas phase. Overall, FR-PA and Ca-Alg improve the thermal stability of the composite paper in different temperature regions under air atmosphere. Ca-Alg reduces the formation of aromatic products and NH3 in the composite paper under N2 atmosphere. Ca-Alg-based paper with excellent flame retardancy was successfully prepared.

Investigation of nickel ammonia phosphate with different morphologies as a new high-efficiency flame retardant for epoxy resin

2019 ◽  
Vol 32 (4) ◽  
pp. 359-370 ◽  
Author(s):  
Weiwei Zhang ◽  
Hongjuan Wu ◽  
Weihua Meng ◽  
Jiahe Li ◽  
Yumeng Cui ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Photoelectron Spectroscopy ◽  
High Efficiency ◽  
Ammonium Phosphate ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
X Ray ◽  
The Matrix

Nanowires, nanosheets, and microflowers of nickel ammonium phosphate (NiNH4PO4·H2O) were synthesized by a mixed solvothermal method and used to improve the flame retardancy of epoxy resin (EP). The solvent concentration and surfactant content were found to play a key role in nucleation and growth of NiNH4PO4·H2O. The structure of NiNH4PO4·H2O was characterized by X-ray diffraction and X-ray photoelectron spectroscopy. The flame retardancy, thermostability, mechanical properties, and flame retardancy mechanism of EP/NiNH4PO4·H2O composites were analyzed using the limiting oxygen index (LOI), cone calorimetry (Cone), mechanical property tests, thermogravimetric analysis, and thermogravimetric–Fourier transform infrared spectroscopy. The results indicated that NiNH4PO4·H2O has proper thermal stability and greatly improves the flame retardancy of EP. The nanosheets outperformed the other morphologies; the EP/5% NiNH4PO4·H2O nanosheets have an LOI of 35.2%, which exceeds that of pure EP (24.7%). Furthermore, Cone showed that these nanosheets have the lowest peak heat release rate and peak smoke production rate, which are 69.1% and 36.5% lower than those of pure EP, respectively. NiNH4PO4·H2O can promote the formation of a stable char layer and release nonflammable gases, thus protecting the matrix by preventing heat and oxygen transfer and reducing the concentration of combustible gas. NiNH4PO4·H2O is expected to serve as a new high-efficiency flame retardant for EP.

Modification of epoxy resin through the self-assembly of a surfactant-like multi-element flame retardant

2016 ◽  
Vol 4 (9) ◽  
pp. 3462-3470 ◽  
Author(s):  
C. Liu ◽  
T. Chen ◽  
C. H. Yuan ◽  
C. F. Song ◽  
Y. Chang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Self Assembly ◽  
The Self

Self-assembly of a surfactant-like flame-retardant POSS-bisDOPO in epoxy resin, can both enhance the flame retardancy and improve the mechanical properties of epoxy resin.

scholarly journals Towards Selection Charts for Epoxy Resin, Unsaturated Polyester Resin and Their Fibre-Fabric Composites with Flame Retardants

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1181
Author(s):  
Noha Ramadan ◽  
Mohamed Taha ◽  
Angela Daniela La Rosa ◽  
Ahmed Elsabbagh
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Polyester Resin ◽  
Unsaturated Polyester ◽  
Polymeric Materials ◽  
Polyester Resins ◽  
Thermosetting Polymers

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.

scholarly journals Core-Shell Graphitic Carbon Nitride/Zinc Phytate as a Novel Efficient Flame Retardant for Fire Safety and Smoke Suppression in Epoxy Resin

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 212 ◽  
Author(s):  
Weiwei Zhang ◽  
Weihong Wu ◽  
Weihua Meng ◽  
Weiya Xie ◽  
Yumeng Cui ◽  
...  
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Fire Safety ◽  
Carbon Nitride ◽  
Graphitic Carbon ◽  
Graphitic Carbon Nitride ◽  
Smoke Suppression ◽  
Core Shell ◽  
Cone Calorimetry

Novel core-shell graphitic carbon nitride/zinc phytate (g-C3N4/PAZn) flame retardant was simple synthetized using two-dimensional g-C3N4 and bio-based PAZn by self-assembly and incorporated into epoxy resin (EP) for improving the fire safety. The flame retardance and smoke suppression were investigated by cone calorimetry. The results indicated that g-C3N4/PAZn-EP displayed outstanding flame retardancy and smoke suppression, for example, the peak heat release rate and peak smoke production rate decreased by 71.38% and 25%, respectively. Furthermore, the flame retardancy mechanism was further explored by char residue and thermal stability analysis. It can be predicted that g-C3N4/PAZn will provide valuable reference about bio-based flame retardant.

scholarly journals Flame Retardancy and Mechanical Properties of Chitosan and DOPO with Different Mass Ratios in Epoxy Resin

2021 ◽  
Author(s):  
Junjie Wang ◽  
Xinyu Wang ◽  
Chenyu Zhou ◽  
Zhiquan Pan ◽  
Hong Zhou
Keyword(s):  
Mechanical Properties ◽  
Heat Release ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Synergistic Effects ◽  
Resin Matrix ◽  
Simultaneous Increase ◽  
Combined System ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index

Abstract This work focused on the effects of chitosan (CS) and 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide (DOPO) on the flammable propertied of epoxy resin matrix. The EP composites were fabricated by direct mixing method through a general curing method. The influence of CS, DOPO and CS / DOPO on the resin was investigated through cone calorimetry tests (CC), UL-94 vertical burning, limiting oxygen index (LOI), thermal gravimetric analyzer (TGA), differential scanning calorimeter (DSC) and thermogravimetric analyzer-Fourier infrared combined system (TG-FTIR). The char residues of modified EPs after CC tests were investigated by FTIR, EDX and XPS. Under the 10% addition of CS / DOPO in EP, with the mass ratio of CS and DOPO of 1 : 1, 1 : 2, 1 : 3, 2 : 1 and 3 : 1, the flame retardancy properties of EPs all increased, but only if EP/10% CS1/DOPO2 and EP/10% CS2/DOPO1 achieved a V-0 rating and their values of LOI were 33.7% and 32.5%, respectively. Compared with EP, the peak heat release rate, peak smoke produce rate and total heat release of EP/10% CS1/DOPO2 and EP/10% CS2/DOPO1 decreased, especially, total smoke release decreased by 61.9% and 71.0%, the char residuals amount increased by 84.3% and 41.6%, and the average CO2 yield decreased by 55.4% and 55.0%, respectively. It is worth nothing that the mechanical properties increased, especially the flexural strength increased by 36.0% and 38.4%, respectively. The results indicated that DOPO and CS had important synergistic effects for simultaneous increase both the flame retardancy and mechanical properties of EP composites.

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