Construction of Charring-Functional Polyheptanazine towards Improvements in Flame Retardants of Polyurethane

Nitrogen-containing flame retardants have been extensively applied due to their low toxicity and smoke-suppression properties; however, their poor charring ability restricts their applications. Herein, a representative nitrogen-containing flame retardant, polyheptanazine, was investigated. Two novel, cost-effective phosphorus-doped polyheptazine (PCN) and cobalt-anchored PCN (Co@PCN) flame retardants were synthesized via a thermal condensation method. The X-ray photoelectron spectroscopy (XPS) results indicated effective doping of P into triazine. Then, flame-retardant particles were introduced into thermoplastic polyurethane (TPU) using a melt-blending approach. The introduction of 3 wt% PCN and Co@PCN could remarkably suppress peak heat release rate (pHRR) (48.5% and 40.0%), peak smoke production rate (pSPR) (25.5% and 21.8%), and increasing residues (10.18 wt%→17.04 wt% and 14.08 wt%). Improvements in charring stability and flame retardancy were ascribed to the formation of P–N bonds and P=N bonds in triazine rings, which promoted the retention of P in the condensed phase, which produced additional high-quality residues.

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Flame Retardance and Char Analysis of an Eco-Friendly Polyurethane Hyperbranched Hybrid Using the Sol–Gel Method

Sustainability ◽

10.3390/su13020486 ◽

2021 ◽

Vol 13 (2) ◽

pp. 486

Author(s):

Ming-Yuan Shen ◽

Chen-Feng Kuan ◽

Hsu-Chiang Kuan ◽

Cing-Yu Ke ◽

Chin-Lung Chiang

Keyword(s):

Flame Retardant ◽

Hybrid Material ◽

Photoelectron Spectroscopy ◽

Flame Retardants ◽

Sol Gel ◽

Flame Retardance ◽

Gel Method ◽

X Ray ◽

Sol Gel Method ◽

Nitrogen Phosphorus

This study used the sol–gel method to synthesize a non-halogenated, hyperbranched flame retardant containing nitrogen, phosphorus, and silicon (HBNPSi), which was then added to a polyurethane (PU) matrix to form an organic–inorganic hybrid material. Using 29Si nuclear magnetic resonance, energy-dispersive X-ray spectroscopy of P- and Si-mapping, scanning electron microscopy, and X-ray photoelectron spectroscopy, this study determined the organic and inorganic dispersity, morphology, and flame retardance mechanism of the hybrid material. The condensation density of the hybrid material PU/HBNPSi was found to be 74.4%. High condensation density indicates a dense network structure of the material. The P- and Si-mapping showed that adding inorganic additives in quantities of either 20% or 40% results in homogeneous dispersion of the inorganic fillers in the polymer matrix without agglomeration, indicating that the organic and inorganic phases had excellent compatibility. In the burning test, adding HBNPSi to PU made the material pass the UL-94 test at the V2 level, unlike the pristine PU, which did not meet the standard. The results demonstrate that after non-halogenated flame retardant was added to PU, the material’s flammability and dripping were lower, thereby proving that flame retardants containing elements such as nitrogen, phosphorus, and silicon exert an excellent flame-retardant synergistic effect.

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Synthesis of Novel Arginine-Based Flame Retardant and Its Application in Lyocell Fabric

Molecules ◽

10.3390/molecules26123588 ◽

2021 ◽

Vol 26 (12) ◽

pp. 3588

Author(s):

Jiayi Chen ◽

Yansong Liu ◽

Jiayue Zhang ◽

Yuanlin Ren ◽

Xiaohui Liu

Keyword(s):

Fourier Transform ◽

Heat Release ◽

Flame Retardant ◽

Photoelectron Spectroscopy ◽

Fourier Transform Infrared ◽

Ftir Analysis ◽

Excellent Thermal Stability ◽

X Ray ◽

Cone Calorimeter Test ◽

Before And After

Lyocell fabrics are widely applied in textiles, however, its high flammability increases the risk of fire. Therefore, to resolve the issue, a novel biomass-based flame retardant with phosphorus and nitrogen elements was designed and synthesized by the reaction of arginine with phosphoric acid and urea. It was then grafted onto the lyocell fabric by a dip-dry-cure technique to prepare durable flame-retardant lyocell fabric (FR-lyocell). X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR) analysis demonstrated that the flame retardant was successfully introduced into the lyocell sample. Thermogravimetric (TG) and Raman analyses confirmed that the modified lyocell fabric featured excellent thermal stability and significantly increased char residue. Vertical combustion results indicated that FR-lyocell before and after washing formed a complete and dense char layer. Thermogravimetric Fourier-transform infrared (TG-FTIR) analysis suggested that incombustible substances (such as H2O and CO2) were produced and played a significant fire retarding role in the gas phase. The cone calorimeter test corroborated that the peak of heat release rate (PHRR) and total heat release (THR) declined by 89.4% and 56.4%, respectively. These results indicated that the flame retardancy of the lyocell fabric was observably ameliorated.

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Silver mirror reaction metallized chromatography paper for supercapacitor application

Flexible and Printed Electronics ◽

10.1088/2058-8585/ac3a13 ◽

2021 ◽

Author(s):

I-Hsuan Chen ◽

Jung-Hsien Chang ◽

Ren-Jie Xie ◽

Chia-Hui Tseng ◽

Sheng-Rong Hsieh ◽

...

Keyword(s):

Flexible Electronics ◽

Photoelectron Spectroscopy ◽

Cost Effective ◽

Water Contact ◽

X Ray ◽

Supercapacitor Application ◽

Resource Limited ◽

Vis Spectroscopy ◽

Silver Mirror ◽

Silver Mirror Reaction

Abstract In this study, the easy-to-operate silver mirror reaction (SMR) was used for metallizing chromatography paper. The SMR-metallized paper was characterized by water contact angle measurements, a surface profiler, X-ray photoelectron spectroscopy, UV-vis spectroscopy, X-ray diffraction, and electrical resistance measurement. The characterization results show that Ag was successfully synthesized on cellulose fibers and was electrically conductive after cyclic bending. Moreover, this SMR-metallized paper was used as electrodes for fabricating a supercapacitor. This SMR-metallized paper could be used for realizing cost-effective flexible electronics applied in on-site biochemical sensing in resource-limited settings.

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Use of anti-solvent to enhance thermoelectric response of hybrid-halide perovskite thin films

Japanese Journal of Applied Physics ◽

10.35848/1347-4065/ac4adb ◽

2022 ◽

Author(s):

Shrikant SAINI ◽

Izuki Matsumoto ◽

Sakura Kishishita ◽

Ajay Kumar Baranwal ◽

Tomohide Yabuki ◽

...

Keyword(s):

Thin Films ◽

Electrical Conductivity ◽

Photoelectron Spectroscopy ◽

High Performance ◽

Cost Effective ◽

Performance Tuning ◽

Charge Carrier Density ◽

X Ray ◽

Thermoelectric Energy Harvesting ◽

Halide Perovskite

Abstract Hybrid halide perovskite has been recently focused on thermoelectric energy harvesting due to the cost-effective fabrication approach and ultra-low thermal conductivity. To achieve high performance, tuning of electrical conductivity is a key parameter that is influenced by grain boundary scattering and charge carrier density. The fabrication process allows tuning these parameters. We report the use of anti-solvent to enhance the thermoelectric performance of lead-free hybrid halide perovskite, CH3NH3SnI3, thin films. Thin films with anti-solvent show higher connectivity in grains and higher Sn+4 oxidation states which results in enhancing the value of electrical conductivity. Thin films were prepared by a cost-effective wet process. Structural and chemical characterizations were performed using x-ray diffraction, scanning electron microscope, and x-ray photoelectron spectroscopy. The value of electrical conductivity and the Seebeck coefficient were measured near room temperature. The high value of power factor (1.55 µW/m.K2 at 320 K) was achieved for thin films treated with anti-solvent.

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Phosphorus Behavior in Heavily Phosphorus-Doped Silicon Surfaces due to Annealing. X-Ray Photoelectron Spectroscopy and Secondary Ion Mass Spectroscopy.

Shinku ◽

10.3131/jvsj.38.295 ◽

1995 ◽

Vol 38 (3) ◽

pp. 295-298 ◽

Cited By ~ 2

Author(s):

Wen Biao YING ◽

Yusuke MIZOKAWA ◽

Yoshitomo KAMIURA ◽

Yong Bing YU ◽

Masafumi NISHIMATSU ◽

...

Keyword(s):

Mass Spectroscopy ◽

Photoelectron Spectroscopy ◽

Silicon Surfaces ◽

Secondary Ion Mass Spectroscopy ◽

X Ray ◽

Doped Silicon ◽

Phosphorus Doped ◽

Secondary Ion

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Electromagnetic Shielding by MXene-Graphene-PVDF Composite with Hydrophobic, Lightweight and Flexible Graphene Coated Fabric

Materials ◽

10.3390/ma11101803 ◽

2018 ◽

Vol 11 (10) ◽

pp. 1803 ◽

Cited By ~ 27

Author(s):

Kanthasamy Raagulan ◽

Ramanaskanda Braveenth ◽

Hee Jang ◽

Yun Seon Lee ◽

Cheol-Min Yang ◽

...

Keyword(s):

Photoelectron Spectroscopy ◽

Spray Coating ◽

Cost Effective ◽

Work Of Adhesion ◽

Shielding Effectiveness ◽

X Ray Diffraction ◽

X Ray ◽

Highest Weight ◽

Coated Fabric ◽

Hydrophobic Nature

MXene and graphene based thin, flexible and low-density composite were prepared by cost effective spray coating and solvent casting method. The fabricated composite was characterized using Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and energy dispersive X-ray (EDX). The prepared composites showed hydrophobic nature with higher contact angle of 126°, −43 mN·m−1 wetting energy, −116 mN·m−1 spreading Coefficient and 30 mN·m−1 lowest work of adhesion. The composites displayed excellent conductivity of 13.68 S·cm−1 with 3.1 Ω·sq−1 lowest sheet resistance. All the composites showed an outstanding thermal stability and constrain highest weight lost until 400 °C. The MXene-graphene foam exhibited excellent EMI shielding of 53.8 dB (99.999%) with reflection of 13.10 dB and absorption of 43.38 dB in 8–12.4 GHz. The single coated carbon fabric displayed outstanding absolute shielding effectiveness of 35,369.82 dB·cm2·g−1. The above results lead perspective applications such as aeronautics, radars, air travels, mobile phones, handy electronics and military applications.

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Facile preparation of uniform polydopamine particles and its application as an environmentally friendly flame retardant for biodegradable polylactic acid

Journal of Fire Sciences ◽

10.1177/0734904120932479 ◽

2020 ◽

Vol 38 (6) ◽

pp. 485-503

Author(s):

Benjamin Tawiah ◽

Bin Yu ◽

Anthony Chun Yin Yuen ◽

Bin Fei

Keyword(s):

Flame Retardant ◽

Polylactic Acid ◽

Flame Retardants ◽

Environmentally Friendly ◽

Environmentally Benign ◽

Commercial Application ◽

Limiting Oxygen Index ◽

Gaseous Products ◽

Peak Heat Release Rate ◽

Insight Into

The demand for environmentally benign flame retardants for biodegradable polymers has become particularly necessary due to their inherently “green” nature. This work reports intrinsically non-toxic polydopamine (PDA) particles as an efficient and environmentally friendly flame retardant for polylactic acid (PLA). 5 wt% PDA loading resulted in a 22% reduction in the peak heat release rate, 34.7% increase in the fire performance index, and lower CO2 production compared to neat PLA. A limiting oxygen index (LOI) value of 27.5% and a V-2 rating was achieved in the UL-94 vertical burning test. Highly aggregated amorphous particulate char was formed with the increasing content of PDA, and a significant reduction in evolved pyrolysis gaseous products was achieved for the PLA/PDA composites as compared with control PLA. This work provides important insight into the potential commercial application of PDA alone as an efficiently green, environmentally benign flame retardant for bioplastic PLA.

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CeO2-dolomite as fire retardant additives on the conventional intumescent coating in steel substrate for improved performance

MATEC Web of Conferences ◽

10.1051/matecconf/201926804009 ◽

2019 ◽

Vol 268 ◽

pp. 04009 ◽

Cited By ~ 1

Author(s):

Joshua Zoleta ◽

Gevelyn Itao ◽

Vannie Joy Resabal ◽

Arnold Lubguban ◽

Ryan Corpuz ◽

...

Keyword(s):

Flame Retardant ◽

Photoelectron Spectroscopy ◽

Flame Retardants ◽

Steel Substrate ◽

Morphological Structure ◽

Fire Retardant ◽

Carbon Chain ◽

Binding Energies ◽

Fire Exposure ◽

Improved Performance

Multiple combinations of CeO2-Dolomite as fillers and Intumescent Flame Retardant (IFR) ingredients were used to optimize the intumescent coatings designed for I-beam steel substrates. The influenced of fillers and various combinations of flame-retardants on the fire protective performance of the coatings were evaluated using vertical Bunsen burner fire test and various characterization techniques. Formula C and Formula F having 1:1 and 2:2 CeO2-Dolomite ratio, obtained the lowest substrate temperature around 150oC and 150.4oC, respectively after 90 minutes fire exposure. Also, the morphological structures of intumescent char observed by SEM-EDX, demonstrated that Formula C and Formula F stimulated the formation of homogeneous and more compacted surface structure. X-ray photoelectron spectroscopy (XPS) provide the binding energies of C and O constituents, it was observed that [-(C2H4)n-] was the most important free radical as it could promote the formation of aromatic carbon chain in the char surface. Finally, the findings of this study revealed that the selection of appropriate fillers and combinations of flame-retardant ingredients significantly influenced the morphological structure of the char layer, of which, Formula C and Formula F produced a char with higher thermal stability, resulting to a more fire resistive IFR coating during fire exposure.

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Synthesis and Cytotoxicity of POSS Modified Single Walled Carbon Nanotubes

Journal of Nanomaterials ◽

10.1155/2015/407437 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Yuhua Xue ◽

Hao Chen

Keyword(s):

Carbon Nanotubes ◽

Photoelectron Spectroscopy ◽

Single Walled Carbon Nanotubes ◽

X Ray ◽

Single Walled Carbon ◽

Amine Functionalized ◽

Low Toxicity ◽

Organic Solutions ◽

Oligomeric Silsesquioxane ◽

Walled Carbon Nanotubes

Single walled carbon nanotubes (SWNTs) decorated with polyhedral oligomeric silsesquioxane (POSS) were synthesized via the amide linkages between the acid treated SWNTs and amine-functionalized POSS. The successful modification of SWNTs with POSS was confirmed by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and UV-Vis spectra. The resulting SWNTs-POSS can be dispersed in both water and organic solutions. The biocompatibility and cytotoxicity of the SWNTs and SWNTs-POSS were evaluated by CCK-8 viability assays, which indicated that SWNTs-POSS exhibit very extremely low toxicity. The low toxicity of the POSS modified SWNTs leads to more opportunities for using carbon nanotubes in biomedical fields.

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The intercalation of ammonium sulfamate into kaolinite and its effect on the fire performance of polypropylene

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705717738291 ◽

2017 ◽

Vol 31 (10) ◽

pp. 1352-1370 ◽

Cited By ~ 5

Author(s):

Wufei Tang ◽

Hongfei Li ◽

Sheng Zhang ◽

Jun Sun ◽

Xiaoyu Gu

Keyword(s):

Flame Retardant ◽

Oxygen Index ◽

Potassium Acetate ◽

Limit Oxygen Index ◽

Fire Performance ◽

X Ray Diffraction ◽

X Ray ◽

Peak Heat Release Rate ◽

Ammonium Sulfamate ◽

Xrd Patterns

Kaolinite has often been intercalated before being introduced into polymers to improve its dispersibility; however, the conventional intercalation usually reduces the flame retardancy of the composite. This work reports our recent efforts on improving both the flame retardant efficiency and dispersibility of kaolinite in polypropylene (PP) by intercalating with ammonium sulfamate (AS). The intercalation had been performed through three steps: dimethyl sulfoxide was firstly introduced into kaolinite layers under supersonic wave, then it was replaced by potassium acetate-aqueous (KAc), and finally the intercalated KAc was replaced by AS to obtain AS-intercalated kaolinite. The structure of intercalated kaolinite was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, and thermogravimetric analysis (TGA). The flammability evaluation by limit oxygen index, vertical burning test (UL-94), cone calorimeters test (CONE), and TGA indicated that the fire resistance, thermal stability, and physical properties of PP can be effectively enhanced by the introduction of AS-intercalated kaolinite. The peak heat release rate (pHRR) value of PP composite containing only 1.5 wt% intercalated kaolinite (1169 kW m−2) had been reduced 13.2% compared with that of the sample containing 1.5 wt% raw kaolinite (1346 kW m−2). The morphology analysis from scanning electron microscope images and XRD patterns demonstrated that the compatibility and dispersibility of kaolinite in PP had been significantly improved by intercalation. The flame retardant mechanism of AS-intercalated kaolinite in PP was proposed.

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