Ammonium polyphosphate, ammonium pentaborate
20493529
Cotton fabrics treated with novel oxidic phases acting as effective smoke suppressants.
Sol gel processes have been applied to cotton fabrics in order to coat the fibres with a silica film, able to improve their thermo oxidative resistance and their combustion behaviour under the irradiative heat flow of a cone calorimeter. To this aim, tetramethoxysilane, inorganic precursor of the silica phase, has been employed alone or coupled with species having either smoke suppressant features (namely, zinc oxide, zinc acetate dihydrate and zinc borate) or well known flame retardant properties (like ammonium pentaborate octahydrate, boron phosphate, ammonium polyphosphate and 9,10 dihydro 9 oxa 10 phosphaphenanthrene 10 oxide) In addition, the use of barium sulphate, which is a smoke suppressant and, at the same time, a flame retardant, has been investigated. Cone calorimetry turned out to be a suitable technique for assessing the flammability and smoke production of the treated fabrics (particularly when referring to total smoke release, smoke production rate and CO and CO2 yields) The composition and morphology of the deposited coatings, assessed by scanning electron microscopy, have been found to influence their combustion behaviour, as well as their thermal and thermo oxidative stability evaluated by thermogravimetric analysis in nitrogen and air, respectively.
Carbohydrate polymers
Jenny Alongi Giulio Malucelli
97390139
Mechanistic study of combustion performance and thermal decomposition behaviour of nylon 6 with added halogen free fire retardants
Mechanistic studies in nylon 6 with added halogen free fire retardants, e.g. ammonium polyphosphate (APP) ammonium pentaborate (APB) red phosphorus, potassium nitrate or melamine and its salts, were carried out using combustion and thermal decomposition approaches. It was shown that APP interacts with nylon 6 producing alkylpolyphosphoric ester which is a precursor of the intumescent char. On the surface of burning polymer, APB forms an inorganic glass protecting the char from oxidation and hindering the diffusion of combustible gases. Red phosphorus reacts with decomposing nylon 6, probably through radical mechanisms producing phosphorus ester species. The condensed phase fire retardant action is proved for red phosphorus. Potassium nitrate, which is a strong oxidizer, reacts with the polymer in condensed phase increasing the char yield. Melamine and its salts mostly provoke flow of nylon 6 leading to extinction of the flame. Furthermore, they induce scission of H 2 C C(O) bonds in nylon 6, which leads to increased cross linking and charring of the polymer.
Sergei V Levchik G F Levchik Alexandr I Balabanovich Giovanni Camino Luigi Costa
210252334
Surface modification of ammonium polyphosphate by supramolecular assembly for enhancing fire safety properties of polypropylene
Abstract Organically modified ammonium polyphosphate (APP) flame retardant is prepared by supramolecular assembly method using melamine formaldehyde (MF) resin and phytic acid (PA) as building blocks. Surface characteristics of APP are modified, resulting in the enhancements in water resistance, dispersion in the polymer matrix and their compatibility. This supramolecular assembly modified APP (APP@MF PA) matches well with charring foaming agent (CFA) to achieve excellent fire safety for polypropylene (PP) and the superiority over conventional APP is observed. Heat, CO and CO2 releases of PP are greatly decreased by the intumescent flame retardant (IFR) formulation containing APP@MF PA and CFA. The modification of APP with MF PA supramolecules are beneficial to improve the yield, insulation properties, graphitization degree and compactness of char. Flame retardant mechanisms are demonstrated according to the investigations on gaseous and condensed phase products. This novel and facile modification method provides a new strategy for improving the flame retardant efficiency of IFR.
Yaru Sun Bihe Yuan Sheng Shang Hong-ming Zhang Yongqian Shi Bin Yu Congrui Qi Haoran Dong Xianfeng Chen Xinlei Yang
216369209
High yield and high performance porous biochar produced from pyrolysis of peanut shell with low dose ammonium polyphosphate for chloramphenicol adsorption
Abstract Adsorptive removal by porous carbon materials has been considered an attractive technique to treat wastewater polluted by antibiotics. To produce porous biochar with high yield and high performance for chloramphenicol adsorption, this study prepared biochar from peanut shells using ammonium polyphosphate via pyrolysis. The combined effects of the main process parameters on biochar production were studied to determine the optimum operating conditions by response surface methodology based on Box Behnken design. Low dose ammonium polyphosphate has a significant positive effect on the yield, surface functional groups, pore volume, and surface area of biochar. This is caused by the richness of nitrogen and phosphorus in ammonium polyphosphate and its flame retardant property. The high yield biochar with a surface area of 979 25 m2/g was obtained at a mass ratio of ammonium polyphosphate/peanut shell of 0.55, at 650 degC with a retention time of 60 min. The as prepared biochar exhibited excellent adsorption performance with a monolayer chloramphenicol adsorption capacity of 423.7 mg/g. This was due to the high surface area, micropores formed by nano sized particles, and richness of N and P containing functional groups. The characterization before and after chloramphenicol adsorption indicated micro pore filling, Van der Waals force, p p interaction, and hydrogen bonding interaction are the main adsorption mechanisms of chloramphenicol adsorption on as prepared biochar. This study offered new insights on the preparation of biochar from waste biomass for application in wastewater treatment.
Jiwen Yang Guozhao Ji Yuan Gao Weng Fu Muhammad Faisal Irfan Lan Mu Yulin Zhang Aimin Li
208746789
Fundamental investigation on the effects of ammonium polyphosphate on flame propagation behaviors of starch dust deflagration
Abstract This work explores the possibility of ammonium polyphosphate (APP) as the inhibitor for starch dust deflagration. The flame propagation behaviors of starch dust samples are investigated in a half closed vertical duct. Flame images and temperature are recorded by high speed camera and fine thermocouples, respectively. The high speed photographs indicate that flame propagation and flame luminous intensity of starch dust at the initial stage are greatly suppressed by APP. Maximum temperature values are also significantly decreased by APP. Thermal decomposition behavior and kinetics of starch samples are studied to ascertain the influence of APP on the decomposition activation energy. The combustion heat release of starch samples are tested by pyrolysis combustion flow calorimetry. Inhibition mechanisms of APP on starch dust deflagration are concluded according to the results of flame propagation, thermal decomposition kinetics and heat release. This work proposes a new strategy for exploration of inhibition mechanisms of dust explosion.
Lian-cong Wang Bihe Yuan Hongming Zhang Saihua Jiang
216481991
Synthesis of a novel polyhydroxy triazine based charring agent and its effects on improving the flame retardancy of polypropylene with ammonium polyphosphate and zinc borate
Abstract A novel polyhydroxy triazine based charring agent, N tris(hydroxymethyl) amino triazine piperazine copolymer (TTPC) was synthesized from piperazine, cyanuric chloride and tris(hydroxymethyl) aminomethane. The chemical structure of TTPC was characterized by Fourier transform infrared spectroscopy and 13C solid state nuclear magnetic resonance. TTPC, ammonium polyphosphate (APP) and zinc borate (ZB) were then introduced into polypropylene (PP) by melt compounding to improve the fire performance of the composites. The test results showed that the presence of 21% APP TTPC ZB with mass ratio of 16:4:1 could significantly reduce the peak heat release rate from 1547 to 230 kW/m2, increase the limiting oxygen index value from 18.0 to 29.6% and upgrade the UL 94 rating from no rating to V 0, accompanied by the elimination of melt dripping. The thermal stability and charring behaviors of the composite samples were investigated by thermogravimetric analysis. The results showed that TTPC was a highly efficient charring agent, and ZB could act as synergist in the intumescent system. Based on the comprehensive study of fire performance, char morphology and mechanical properties, it can be concluded that TTPC is a superior charring agent, especially compared with the generally used pentaerythritol.
Quan Wu Jia Guo Bin Fei Xinjian Li Jun Sun Xiaoyu Gu Hongfei Li Sheng Zhang
219743918
Synergy effect between quaternary phosphonium ionic liquid and ammonium polyphosphate toward flame retardant PLA with improved toughness
Abstract The development of poly(lactic acid) (PLA) composites having flame retardancy, tensile toughness and transparency is the state of the art, which requires meticulous selection and combination of additives. To achieve this goal, an ionic liquid (IL) tetrabutylphosphonium tetrafluoroborate is synthesized and used as a synergist for ammonium polyphosphate (APP) Due to the high synergistic effect between them, only 1.5 wt% IL and 1.5 wt% APP (total amount of 3 wt% can endow PLA with fire safety, i.e. limiting oxygen index (LOI) of 27.2, UL 94 V 0 rating and low heat release rate of 290 kW m 2. Besides, the elongation at break of PLA containing 3 wt% IL/APP increases from 8.5% of PLA to 204.6% Meanwhile, the incorporation of IL/APP has tiny impact on the transparency of PLA. The PLA/IL/APP possessing toughness and flame retardancy shows great potentials in the fields of packaging, automotive and electronic and electric industry in the future.
Yun-Wan Jia Xi Zhao Teng Fu Defu Li Yan Guo Xiu-Li Wang Yu-Zhong Wang
209892556
Improved pyrolysis behavior of ammonium polyphosphate melamine expandable (APP MEL EG) intumescent fire retardant coating system using ceria and dolomite as additives for I beam steel application
This study describes the effects of ceria (CeO2) and dolomite [CaMg(CO3)2] additives on the pyrolysis behavior and fire resistive property of conventional intumescent flame retardant (IFR) coating system for I beam steel substrate called ammonium polyphosphate melamine expandable graphite (APP MEL EG) system. The fire resistance of various formulations was evaluated using the standard vertical Bunsen burner fire test. Thermogravimetric analysis (TGA) was used to understand the degradation of coating formulations. Observations by scanning electron microscopy with energy dispersive X ray spectroscopy (SEM EDX) demonstrated that significant amounts of additives favored the formation of homogeneous compacted char structures, which were predominantly composed of carbon (C) phosphorus (P) and oxygen (O) These three main components of the char were also found to be in various binding combinations with other lighter elements like nitrogen (N) and hydrogen (H) as illustrated by the attenuated total reflectance Fourier transform infrared (ATR FTIR) spectroscopy results. X ray photoelectron spectroscopy (XPS) further suggest that polyethylene((CH2 C2H2 CH2)n free radicals were abundant on the char surface for the two best formulations and the binding energy of this radical promoted the formation of aromatic carbon chains that enhanced the char's thermal stability. This means that the selection of appropriate additives and combinations of flame retardant ingredients could significantly change the morphology of the char layer and improve its thermal stability during fire exposure.
Heliyon
Joshua B Zoleta Gevelyn B Itao Vannie Joy T Resabal Arnold A Lubguban Ryan Corpuz Mayumi Ito Naoki Hiroyoshi Carlito Baltazar Tabelin
221258854
Investigation on thermokinetic suppression of ammonium polyphosphate on sucrose dust deflagration: Based on flame propagation, thermal decomposition and residue analysis.
In this investigation, ammonium polyphosphate (APP) is applied to suppress the deflagration of sucrose dust. Through the systematic research on flame propagation images and temperature, decomposition behavior of powder samples and the compositions of deflagration residue, the suppression performance and mechanism of APP on sucrose deflagration are profoundly summarized. Timing diagrams show that APP contributes to reduce deflagration flame brightness, increases ignition delay time and flame fault area. The minimum inerting concentration of APP for sucrose deflagration is determined to be 8 From the collected deflagration flame temperature curves, it is confirmed that APP can delay peak temperature arrival time, weaken temperature fluctuation, and decrease peak values of flame temperature and temperature rising rate. Through the analysis on thermal decomposition of samples and deflagration residue, it is reflected that APP has superior composite suppression effect. It can not only absorb reaction heat, but also decrease deflagration exotherm to improve thermal stability of sucrose particles. Thus, the easily oxidized components in sucrose are protected, and deflagration intensity is effectively weakened. This work provides a new solution for prevention and suppression deflagration of dust waste in sugar industry.
Journal of hazardous materials
Chuyuan Huang Bihe Yuan Hongming Zhang Qi Zhao Ping Li Xianfeng Chen Yalong Yun Gongqing Chen Mengmeng Feng Yong Li
218931753
Ammonium pentaborate crystals with adjustable and bright phosphorescence and long lifetime
Abstract As a small molecule boron based compound, ammonium pentaborate was prepared by a solvothermal synthesis by controlling the crystal growth process. As prepared ammonium pentaborate crystals consisted of two perpendicular six membered rings with powerful intermolecular interaction. A resonance hybrid of Lewis acid formed by the combination of five monovalent boric acids and coordinated with an ammonium ion. The planar six membered ring and alternating B O provide p bond orbitals and anti p* bond orbitals. The crystals exhibited a novel phosphorescence phenomenon at room temperature with excited wavelength dependence and long lifetime. Broad phosphorescence spectra show bright blue and green emitting excited at 250 and 360 nm while their phosphorescence lifetime is up to 1.63 and 1.49 s, respectively. The change of phosphorescence with excited wavelength is ascribed to the electronic energy level. This result provides a new idea for synthesizing new type phosphorescent materials.
Yuxiang Song Junpeng Wang Ling Chen Ping Yang