Multi‐element heterocyclic compound derived from DOPO and thiadiazole toward flame‐retardant epoxy resin with satisfactory mechanical properties

2021 ◽  
pp. 52036
Author(s):  
Jiahao Zou ◽  
Huajun Duan ◽  
Junjun Zhang ◽  
Jianfan Cao ◽  
Chenhao Zhang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Heterocyclic Compound

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 Hybrid Biocomposites Based on Used Coffee Grounds and Epoxy Resin: Mechanical Properties and Fire Resistance

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Tuan Anh Nguyen ◽  
Quang Tung Nguyen
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Oxygen Index ◽  
Low Cost ◽  
Sem Images ◽  
Coffee Grounds ◽  
Wide Range ◽  
Sustainable Materials ◽  
Flame Retardant Properties

Studies on using biomaterials hybridized with other materials to produce biomaterials have been paid more attention due to their low cost, abundance, renewability, and degradability. Therefore, these materials are ecofriendly and nontoxic to humans. A large number of used coffee grounds (SCGs) are often discarded and replacements are necessary for dealing with environmental problems. This work developed sustainable materials by reusing SCGs. Used coffee grounds were mixed with epoxy resin at different amounts: 30 wt %, 40 wt %, 50 wt %, and 60 wt %. SCGs were treated with 0.5 N NaOH, at SCGs/NaOH ratio of 1 : 2. SEM images showed that the material with 30 wt % SCGs has good compatibility without phase division on the SCGs-epoxy interface. Results of mechanical properties of epoxy composites with 30 wt % SCGs are as follows: tensile strength of 44.81 ± 10 MPa, flexural strength of 80.07 ± 0.16 MPa, compressive strength of 112.56 ± 0.11 MPa, and Izod strength and impact of 8.21 ± 0.19 kJ/m2. In terms of flame-retardant properties, the oxygen index is limited to 20.8% ± 0.20 and the burning rate according to UL94HB is 27.02 ± 0.29 mm/min. The obtained results indicate that it is possible to produce biohybrid composites from epoxy resin and SCGs. This work offers an ecofriendly alternative method to use the waste of the coffee industry. It contributes to improvements of the general characteristics of composites such as mechanical, thermal, and flame-retardant properties. This work proved that SCGs have a high potential to be used in a wide range of composite materials for civil engineering applications.

scholarly journals The Effect of Multilevel Carbon Reinforcements on the Fire Performance, Conductivity, and Mechanical Properties of Epoxy Composites

Polymers ◽  
2019 ◽  
Vol 11 (2) ◽  
pp. 303 ◽  
Author(s):  
Andrea Toldy ◽  
Gábor Szebényi ◽  
Kolos Molnár ◽  
Levente Tóth ◽  
Balázs Magyar ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Thermal Conductivity ◽  
Flame Retardant ◽  
Epoxy Resin ◽  
Impact Resistance ◽  
Fire Performance ◽  
Multiwalled Carbon ◽  
Peak Heat Release Rate ◽  
Flame Retarded ◽  
The Impact

We studied the effect of a multilevel presence of carbon-based reinforcements—a combination of conventional load-bearing unidirectional carbon fiber (CF) with multiwalled carbon nanotubes (CNT) and conductive CNT-containing nonwoven carbon nanofabric (CNF(CNT))—on the fire performance, thermal conductivity, and mechanical properties of reference and flame-retarded epoxy resin (EP) composites. The inclusion of carbon fibers and flame retardant reduced the peak heat release rate (pHRR) of the epoxy resins. The extent to which the nanoreinforcements reduced the pHRR depended on their influence on thermal conductivity. Specifically, high thermal conductivity is advantageous at the early stages of degradation, but after ignition it may lead to more intensive degradation and a higher pHRR; especially in the reference samples without flame retardant. The lowest pHRR (130 kW/m2) and self-extinguishing V-0 UL-94 rating was achieved in the flame-retarded composite containing all three levels of carbon reinforcement (EP + CNF(CNT) + CNT + CF FR). The plasticizing effect of the liquid flame retardant impaired both the tensile and flexural properties; however, it significantly enhanced the impact resistance of the epoxy resin and its composites.

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