Improvement of thermoplastic polyurethane's flame retardancy and thermal conductivity by leaf‐shaped cobalt‐zeolitic imidazolate framework –modified graphene and intumescent flame retardant

2020 ◽  
Vol 32 (1) ◽  
pp. 228-240
Author(s):  
Wenzong Xu ◽  
Chuanming Cheng ◽  
Zhongqiong Qin ◽  
Di Zhong ◽  
Zihao Cheng ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Intumescent Flame Retardant ◽  
Zeolitic Imidazolate Framework ◽  
Modified Graphene

scholarly journals Effect of Graphene on Flame Retardancy of Graphite Doped Intumescent Flame Retardant (IFR) Coatings: Synergy or Antagonism

Coatings ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 94 ◽  
Author(s):  
Yachao Wang ◽  
Jiangping Zhao
Keyword(s):  
Particle Size ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Antagonistic Effect ◽  
Intumescent Flame Retardant ◽  
Flame Resistance ◽  
Graphene Sample ◽  
Peak Heat Release Rate ◽  
Modified Graphene Oxide ◽  
Modified Graphene

A comparative study between graphene and modified graphene oxide (mGO) on the flame retardancy of graphite doped intumescent flame retardant (IFR) coatings is preliminarily investigated by cone calorimeter (CC), XRD, and SEM, with the final aim of clarifying the interactions between different graphenes and graphite doped coatings (polyester resin-ammonium polyphosphate-urea-pentaerythritol). The CC results determine that graphene exerts an obviously antagonistic effect on flame resistance, evidenced by the increased peak heat release rate (p-HRR) of 56.9 kW·m−2 for SD8+graphene (sample coating contains graphite with a particle size of 8 μm and 0.5 wt.% graphene as dopant), which increased by 80.6% compared with SD8 (coating contains graphite with a particle size of 8 μm); substitution with graphene or mGO imparts an acceleration of fire growth, because graphene inertness improves the viscosity of melting system, evidenced by the cracked appearance and porous structure of SD8+graphene. However, the higher reactivity of mGO favors the combustion; the barrier effect inhibits the transfer of mass and heat simultaneously, leading to a slight influence on flame retarding efficiency.

The effect of boric acid on flame retardancy of intumescent flame retardant polypropylene composites including nanoclay

2021 ◽  
pp. 089270572110523
Author(s):  
Yasin Demirhan ◽  
Recep Yurtseven ◽  
Nazım Usta
Keyword(s):  
Thermal Conductivity ◽  
Boric Acid ◽  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Boron Oxide ◽  
Experimental Studies ◽  
Intumescent Flame Retardant ◽  
Limiting Oxygen Index ◽  
Ul 94

In this study, different amounts of boric acid (BA, 1.25, 2.5, 3.75 and 5.0 wt%) were used to enhance the effectiveness of an intumescent flame retardant (IFR) system composed of ammonium polyphosphate (APP) and pentaerythritol (PER) in polypropylene (PP) including 2 wt% montmorillonite nanoclay (MMT). Meanwhile, metaboric acid and boron oxide which were generated by the decomposition of BA appeared in the melt compounding and the burning processes, respectively. Extensive experimental studies were performed to investigate the effects of BA/boron oxide and MMT combinations on the properties of PP/IFR. The fire resistances of the composites were studied by UL 94, limiting oxygen index (LOI) and cone calorimetry tests. The thermal properties were determined by using thermogravimetric analysis, differential scanning calorimetry and thermal conductivity measurements. In addition, the mechanical properties of the composites were examined. The experimental results revealed that although the additions of 1.25 and 2.5 wt% BA with 2 wt% MMT significantly enhanced thermal and flame resistances of PP composites, 3.75 and 5.0 wt% BA additions generated antagonistic effects and deteriorated the fire resistance of the composites. The sample including 2.5 wt% BA addition achieved the best flame retardancy. The LOI value was increased from 18 to 31% with UL 94 V-0 rating. In addition, the peak heat release rate was reduced from 668.6 to 150.0 kW/m2 and the total heat release value was decreased from 247.9 to 98.4 MJ/m2. In the meantime, the thermal conductivity was increased from 0.22 up to 0.28 W/mK. Furthermore, CO, CO2 and the smoke productions were significantly decreased with respect to PP. NO generation was decreased with BA replacements. At the same time, although there was a slight decrease in the tensile strength, the flexural strength significantly increased with BA and MMT additions.

An efficient method to improve simultaneously the water resistance, flame retardancy and mechanical properties of POE intumescent flame-retardant systems

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16328-16339 ◽  
Author(s):  
Rui-Min Li ◽  
Cong Deng ◽  
Cheng-Liang Deng ◽  
Liang-Ping Dong ◽  
Hong-Wei Di ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Efficient Method ◽  
Water Resistance ◽  
Intumescent Flame Retardant

The water resistance, flame retardancy and mechanical properties of POE intumescent flame-retardant systems were improved simultaneously.

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