scholarly journals Synergistic Effects of Two-Dimensional MXene and Ammonium Polyphosphate on Enhancing the Fire Safety of Polyvinyl Alcohol Composite Aerogels

Polymers ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 1964 ◽  
Author(s):  
Xinxin Sheng ◽  
Sihao Li ◽  
Yanfeng Zhao ◽  
Dongsheng Zhai ◽  
Li Zhang ◽  
...  
Keyword(s):  
Transition Metal ◽  
Polyvinyl Alcohol ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Fire Hazard ◽  
Ammonium Polyphosphate ◽  
Transition Metal Carbide ◽  
Metal Carbide ◽  
Limiting Oxygen Index ◽  
Composite Aerogels

Fire and smoke suppressions of polyvinyl alcohol (PVA) aerogels are urgently required due to the serious fire hazard they present. MXene, a 2D transition-metal carbide with many excellent properties, is considered a promising synergist for providing excellent flame retardant performance. PVA/ammonium polyphosphate (APP)/transition metal carbide (MXene) composite aerogels were prepared via the freeze-drying method to enhance the flame retardancy. Thermogravimetric analysis, limiting oxygen index, vertical burning, and cone calorimeter tests were executed to investigate the thermal stability and flame retardancy of PVA/APP/MXene (PAM) composite aerogels. The results demonstrated that MXene boosted the flame retardancy of PVA-APP, and that PAM-2 (with 2.0 wt% MXene loading) passed the V-0 rating, and reached a maximum LOI value of 42%; Moreover, MXene endowed the PVA-APP system with excellent fire and smoke suppression performance, as the the peak heat release rate and peak smoke production rate were significantly reduced by 55% and 74% at 1.0 wt% MXene loading. The flame retardant mechanism was systematically studied, MXene facilitated the generation of compact intumescent residues via ita catalyst effects, thus further restraining the release of heat and smoke. This work provides a simple route to improve the flame retardancy of PVA aerogels via the synergistic effect of MXene and APP.

scholarly journals Enhanced Thermal Insulation and Flame-Retardant Properties of Polyvinyl Alcohol-Based Aerogels Composited with Ammonium Polyphosphate and Chitosan

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
MinYi Luo ◽  
Jiayou Xu ◽  
Shu Lv ◽  
XueFeng Yuan ◽  
Xiaolan Liang
Keyword(s):  
Polyvinyl Alcohol ◽  
Heat Release ◽  
Flame Retardant ◽  
Thermal Insulation ◽  
Heat Release Rate ◽  
Flame Retardancy ◽  
Release Rate ◽  
Ammonium Polyphosphate ◽  
Composite Aerogel ◽  
Composite Aerogels

Polyvinyl alcohol- (PVA-) based aerogels have attracted widespread attention owing to their low cost, eco-friendliness, and low density. However, the applications of PVA-based aerogels are limited by their flammability. In this study, a flame retardant, ammonium polyphosphate (APP), and a biopolymer, chitosan (CS), were added to polyvinyl alcohol (PVA), and the polymer was further crosslinked using boric acid (H3BO3). In the PVA aerogels, the negatively charged APP and positively charged CS formed a polyelectrolyte complex (PEC) through ionic interaction. Cone calorimetry and vertical burning tests (UL-94) indicated that the PVA composite aerogels have excellent flame retardancy; they could decrease the heat release rate, total heat release rate, and carbon dioxide (CO2) generation. Both PVA/H3BO3 and APP-CS in the composite aerogel could be burned to carbon, and the foamed char layer could act together to impart the PVA composite aerogels with good flame retardancy. Further, the decrease in the temperature at the backside of the aerogels with increasing APP-CS content, as determined by the flame-spraying experiment, indicated that the PVA-based aerogels with APP-CS can also serve as thermal insulation materials. This work provides an effective and promising method for the preparation of PVA-based aerogels with good flame retardancy and thermal insulation property for construction materials.

scholarly journals Layer-by-layer assembly flame-retardant and anti-dripping treatment of polyethylene terephthalate fabrics

2019 ◽  
Vol 14 ◽  
pp. 155892501987030
Author(s):  
Yinchun Fang ◽  
Xinhua Liu ◽  
Cuie Wang
Keyword(s):  
Flame Retardant ◽  
Polyethylene Terephthalate ◽  
Flame Retardancy ◽  
Alkali Treatment ◽  
Ammonium Polyphosphate ◽  
Layer By Layer ◽  
Limiting Oxygen Index ◽  
Layer By Layer Assembly ◽  
Branched Polyethylenimine ◽  
Layer Assembly

Layer-by-layer assembly is a simple and effective method which has been widely studied to improve the flame retardancy of textiles in recent years. In this article, flame-retardant and anti-dripping polyethylene terephthalate fabrics were successfully prepared by layer-by-layer assembly branched polyethylenimine and ammonium polyphosphate on their surface. The results of limiting oxygen index values and vertical burning test revealed that the flame retardancy and anti-dripping performance of polyethylene terephthalate fabrics were improved after the layer-by-layer assembly treatment; especially, the dripping phenomenon was eliminated when the number of branched polyethylenimine/ammonium polyphosphate bilayers was over 10. The influence of alkali treatment of polyethylene terephthalate fabrics before layer-by-layer assembly was also investigated. The results showed that alkali treatment of the polyethylene terephthalate fabrics would promote the combination of polyethylene terephthalate fabrics and the charged flame retardants indicating better flame retardancy. The results of thermogravimetric analysis revealed that layer-by-layer assembly treatment of polyethylene terephthalate fabrics would promote char formation both under the nitrogen atmosphere and under the air atmosphere which may act through condensed phase action. The scanning electron microscopy images of the char residues revealed that the layer-by-layer assembly treatment of polyethylene terephthalate fabrics would promote the formation of a compact and intact char residue, which was beneficial for the improvement of flame retardancy and anti-dripping performance. This research would provide the experimental basis for the effective flame retardancy and anti-dripping performance of polyethylene terephthalate fabric.

scholarly journals Fabrication of Diaminodiphenylmethane Modified Ammonium Polyphosphate to Remarkably Reduce the Fire Hazard of Epoxy Resins

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3221
Author(s):  
Feiyue Wang ◽  
Jiahao Liao ◽  
Long Yan ◽  
Hui Liu
Keyword(s):  
Flame Retardant ◽  
Epoxy Resins ◽  
Oxygen Index ◽  
Fire Hazard ◽  
Ammonium Polyphosphate ◽  
Total Heat Release ◽  
Limiting Oxygen Index ◽  
Ion Exchange Reaction ◽  
Comparable Level ◽  
Ep Matrix

A novel diaminodiphenylmethane (DDM) modified ammonium polyphosphate (APP) flame retardant, DDP, was successfully synthesized via ion-exchange reaction. DDP was introduced into epoxy resins (EPs) to reduce flammability. A comparable level of DDP exerts better flame-retardant and smoke suppression efficiencies in EP than APP. An EP blend containing 15 wt% DDP displays a limiting oxygen index (LOI) value of 37.1% and a UL 94 V-0 rating, and further exhibits a 32.3% reduction in total heat release and a 48.0% reduction in total smoke production compared with pure EP. The presence of DDP greatly facilitates char formation during combustion, and the char mass from thermal decomposition of an EP blend is 37.8% smaller than that of an EP blend containing 15 wt% DDP at 800 °C. The incorporation of DDP into EP blends has a smaller impact on the glass transition temperature and tensile strength than those of a comparable level of APP. This reflects the better compatibility of DDP with the EP matrix compared with that for APP.

Silica precursor as synergist for cotton flame retardancy

2016 ◽  
Vol 28 (3) ◽  
pp. 378-386 ◽  
Author(s):  
Ana Marija Grancaric ◽  
Lea Botteri ◽  
Jenny Alongi ◽  
Anita Tarbuk
Keyword(s):  
Thermal Properties ◽  
Synergistic Effect ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Ammonium Polyphosphate ◽  
Limiting Oxygen Index ◽  
Excellent Thermal Stability ◽  
Content Type ◽  
Silica Precursor

Purpose – The cotton and its blends is the most commonly used textile material in the design and production of protective clothing. However, as the cellulose textiles are the most flammable materials it is necessary to improve its flame retardancy. The government regulations have been the driving force for developing durable flame retardants finishes for textile, to improve its performance and to reduce the negative impact on the environment. The paper aims to discuss these issues. Design/methodology/approach – This paper investigates the effect of silica precursor (tetraethoxysilane – TEOS) added in bath with conventional flame retardant urea/ammonium polyphosphate in full and half concentration for achieving environmental-friendly cotton flame retardancy. Silica precursors have excellent thermal stability and high heat resistance with very limited release of toxic gases during the thermal decomposition. Synergistic effect between urea/ammonium polyphosphate and TEOS has been calculated. Thermal properties of treated cotton fabrics were determined by limiting oxygen index (LOI), thermogravimetric analysis (TGA) and microscale combustion calorimeter (MCC). Findings – TEOS, significantly improves the flame retardancy of cotton when added in the bath with conventional flame retardants urea/ammonium polyphosphate by increasing the LOI values and other thermal properties as increasing char residue measured by TGA and higher heat release rate measured by MCC. Originality/value – This paper represent a good synergistic effect between urea/ammonium polyphosphate and TEOS. This phenomena is evident in better thermal properties when TEOS was added in the bath with conventional flame retardant especially for half concentration of urea/ammonium polyphosphate.

scholarly journals Flame Retardancy, Fire Behavior, and Flame Retardant Mechanism of Intumescent Flame Retardant EPDM Containing Ammonium Polyphosphate/Pentaerythrotol and Expandable Graphite

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4035 ◽  
Author(s):  
Junsheng Wang ◽  
Lei Xue ◽  
Bi Zhao ◽  
Guide Lin ◽  
Xing Jin ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Fire Behavior ◽  
Intumescent Flame Retardant ◽  
Ammonium Polyphosphate ◽  
Infrared Spectrometry ◽  
Expandable Graphite ◽  
Physical Interaction ◽  
Limiting Oxygen Index

The intumescent flame retardant ethylene–propylene–diene rubber (EPDM) was prepared using intumescent flame retardant (IFR), including ammonium polyphosphate (APP) /pentaerythrotol (PER) and expandable graphite (EG), as the flame retardant agent. The effects of IFR and EG on the flame retardancy, fire behavior, and thermal stability of the EPDM were investigated. The results show that IFR and EG have excellent synergistic flame retardant effects. When the mass ratio of IFR to EG is 3:1 and the total addition content is 40 phr, the limiting oxygen index (LOI) value of the EPDM material (EPDM/IFR/EG) can reach 30.4%, and it can pass a V-0 rating in the vertical combustion (UL-94) test. Meanwhile, during the cone calorimetry test, the heat release rate and total heat release of EPDM/IFR/EG are 69.0% and 33.3% lower than that of the pure EPDM, respectively, and the smoke release of the material also decreases significantly, suggesting that the sample shows good fire safety. In addition, the flame retardant mechanism of IFR and EG is systematically investigated by thermogravimetric analysis/infrared spectrometry (TG-IR), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscopy (SEM), and the results indicate that IFR and EG have only physical interaction. Moreover, the reason why IFR exhibits a poor flame retardant effect in EPDM materials is explained.

scholarly journals True Nature of the Transition-Metal Carbide/Liquid Interface Determines Its Reactivity

ACS Catalysis ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 4920-4928
Author(s):  
Christoph Griesser ◽  
Haobo Li ◽  
Eva-Maria Wernig ◽  
Daniel Winkler ◽  
Niusha Shakibi Nia ◽  
...  
Keyword(s):  
Transition Metal ◽  
Liquid Interface ◽  
Transition Metal Carbide ◽  
Metal Carbide ◽  
True Nature

scholarly journals Solvent‐Assisted Anisotropic Cleavage of Transition Metal Carbide into 2D Nanoflakes

2021 ◽  
pp. 2100039
Author(s):  
Chen-Xia Hu ◽  
Zhen Tian ◽  
Qi Xiao ◽  
Zhen-Tong Zhu ◽  
Xiang-Yang Li ◽  
...  
Keyword(s):  
Transition Metal ◽  
Transition Metal Carbide ◽  
Metal Carbide

Tribo-mechanical properties of reactive magnetron sputtered transition metal carbide coatings

2017 ◽  
Vol 114 ◽  
pp. 234-244 ◽  
Author(s):  
D. Dinesh Kumar ◽  
N. Kumar ◽  
S. Kalaiselvam ◽  
R. Radhika ◽  
Arul Maximus Rabel ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Transition Metal ◽  
Transition Metal Carbide ◽  
Reactive Magnetron ◽  
Metal Carbide ◽  
Carbide Coatings

Durable Transition-Metal-Carbide-Supported Pt-Ru Anodes for Direct Methanol Fuel Cells

Fuel Cells ◽  
2012 ◽  
Vol 12 (1) ◽  
pp. 146-152 ◽  
Author(s):  
K. G. Nishanth ◽  
P. Sridhar ◽  
S. Pitchumani ◽  
A. K. Shukla
Keyword(s):  
Fuel Cells ◽  
Transition Metal ◽  
Direct Methanol Fuel Cells ◽  
Transition Metal Carbide ◽  
Metal Carbide ◽  
Direct Methanol ◽  
Methanol Fuel Cells
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