Mass Ratio Of Ammonium Polyphosphate Research Articles

A novel sustainable strategy of upcycled waste polyphenylene sulfide filter bag: From waste polyphenylene sulfide powder to char‐forming agent for flame retardant epoxy

AbstractPolyphenylene sulfide (PPS) filter bag is widely used in the field of high temperature filtration of coal dust because of its high temperature resistance and stable chemical properties. However, as nondegradable solid waste, incineration is main solution for waste PPS filter materials which also brings harm to the environment. To achieve green recycling and efficient utilization of waste PPS filter material, waste PPS is utilized as the charring agent together with ammonium polyphosphate (APP) to form a compound flame retardant to improve flame retardancy of epoxy resin (EP). Due to the excellent char‐forming ability of PPS, good performance of EP/APP/PPS composites is obtained in the rigorous combustion test. When the mass ratio of APP and waste PPS is 3:1 and the total load is 15 wt%, EP/IFR3 composite can pass the UL‐94 V‐0 rating, and its LOI increase to 28.1%. Furthermore, cone calorimetry tests presented its peak heat and smoke release rates were reduced by 49.9% and 63.6% compared with neat EP, respectively. Residual carbon analysis shows that this system is mainly a condense‐phase flame‐retardant mechanism. In addition, due to poor dispersion and compatibility, the flexural performance and thermal stability are destroyed to a certain extent.

Synthesis of New S-Triazine Bishydrazino and Bishydrazido-Based Polymers and Their Application in Flame-Retardant Polypropylene Composites.

In this study six new s-triazine bishydrazino and bishydrazido-based polymers were synthesized via condensation of bishydrazino s-triazine derivatives with terephthaldehyde or via nucleophilic substitution of dichloro-s-triazine derivatives with terephthalic acid hydrazide. The synthesized polymers were characterized by different techniques. The new polymers displayed good thermal behavior with great values in terms of limited oxygen indexed (LOI) 27.50%, 30.12% for polymers 5b,c (bishydrazino-s-triazine based polymers) and 27.23%, 29.86%, 30.85% for polymers 7a–c (bishydrazido-s-triazine based polymers) at 800 °C. Based on the LOI values, these polymers could be classified as flame retardant and self-extinguishing materials. The thermal results also revealed that the type of substituent groups on the triazine core has a considerable impact on their thermal behavior. Accordingly, the prepared polymers were mixed with ammonium polyphosphate (APP) in different proportions to form an intumescent flame-retardant (IFRs) system and were introduced into polypropylene (PP) to improve the flame-retardancy of the composites. The best results were obtained with a mass ratio of APP: 5a–c or 7a–c of 2:1, according to the vertical burning study (UL-94). In addition, the presence of 25% “weight ratio” of IFR in the composite showed great impact and passed UL-94 V-0 and V-1 tests.

Synthesis, Characterization of sym-2,4,6-trisubstituted-s-Triazine Derivatives and Their Effects on Flame Retardancy of Polypropylene Composites

Polypropylene (PP) is flammable material, which brings latent danger to the environment and human society. Therefore, developing new environmentally friendly and effective flame-retardant is one of the most important ways to improve the flame retardancy of PP and improve safety during its lifetime. Herein, we describe the synthesis of five sym-2,4,6-trisubstituted-s-triazine derivatives, namely, N2,N4,N6-triphenyl-1,3,5-triazine-2,4,6-triamine (TAT), N2,N4,N6-tris(4-bromophenyl)-1,3,5-triazine-2,4,6-triamine (TBAT), N2,N4,N6-tris(4-chlorophenyl)-1,3,5-triazine-2,4,6-triamine (TCAT), 4,4′,4″-((1,3,5-triazine-2,4,6-triyl) tris(azanediyl)) triphenol (THAT), and N2,N4,N6-tris(4-methoxyphenyl)-1,3,5-triazine-2,4,6-triamine (TMAT), from the reaction of cyanuric chloride and p-substituted aniline employing conventional heating or microwave irradiation. The prepared compounds characterized by different techniques, such as Fourier-transform infrared (FTIR), Ultra-Violet and Visible (UV-Vis), Nuclear Magnetic Resonance spectroscopy (1H-NMR and 13C-NMR), Thermogravimetric Analysis (TGA), and differential scanning calorimetry (DSC). The effect of substituent on the aniline moiety has great impact on its thermal stability, as observed from the TGA and DSC data. Based on the TGA and DSC results, three triazine derivatives TAT, TBAT, and TMAT were used as charring agents in the presence of different proportions of ammonium polyphosphate (APP) to form an intumescent flame-retardant (IFR) system, to improve the flame retardancy of PP. The flammability property of PP was investigated by a vertical burning test (UL94). The results of UL94 revealed that the TXAT/APP (IFR) system influence the PP and could improve the flame retardancy of PP. Best results were obtained with the mass ratio of APP and TXAT 2:1. When the IFR loading was 25 wt%, it displayed great influence and passed V-0 with TMAT, and V-1 with both TAT and TBAT in the UL94 test.

Synthesis of a Carrageenan-Iron Complex and Its Effect on Flame Retardancy and Smoke Suppression for Waterborne Epoxy.

A k-carrageenan–iron complex (KC–Fe) was synthesized by complexation between degraded KC and FeCl3. Furthermore, KC–Fe and ammonium polyphosphate (APP) were simultaneously added into waterborne epoxy (EP) to improve its flame retardancy and smoke suppression performance. The structure and properties of KC–Fe were assessed using Fourier transform infrared spectroscopy (FTIR), ultraviolet (UV) spectroscopy, thermo gravimetric analysis (TGA), and X-ray powder diffraction analysis (XRD). The analysis showed that KC–Fe was successfully synthesized and exhibited good thermal properties with a 49% char residue at 800 °C. The enhanced flame retardancy and smoke suppression performance of waterborne epoxy were evaluated using a limiting oxygen index (LOI) and UL-94. Moreover, the flame retardancy of waterborne epoxy coated on a steel plate was also investigated using cone calorimetry. The results showed that the flame-retardant waterborne epoxy blend exhibited the best flame retardancy when the mass ratio of APP and KC–Fe was 2:1. The total heat release (THR) and total smoke production (TSP) was decreased by 44% and 45%, respectively, which indicated good fire safety performance and smoke suppression properties. Analysis of the residual char using FTIR, SEM, and elemental analysis (EDS) indicated that the action of KC–Fe was promoted by the presence of APP. The formation of a dense thermal stable char layer from an intumescent coating was essential to protect the underlying materials.

Flame retardancy and thermal degradation of halogen-free flame-retardant biobased polyurethane composites based on ammonium polyphosphate and aluminium hypophosphite

In this work, based on castor oil (CO), flame retardant polyurethane sealants (FRPUS) with ammonium polyphosphate (APP) and aluminum hypophosphite (AHP) were prepared. The synergistic flame retardant effects between APP and AHP on flame retardancy, thermal stability, and flame retardant mechanisms of FRPUS were investigated. It was found that when the mass ratio of APP and AHP was 5:1, the limiting oxygen index (LOI) value of FRPUS increased to 35.1%, In addition, at this ratio, the parameters from cone calorimeter testing (CCT) were reduced; these parameters include peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR) and total smoke production (TSP). The thermal decomposition behavior of the FRPUS was investigated by thermogravimetric analysis (TGA). The results showed that AHP improved the thermal stability of the PUS/APP system and increased char residue at high temperatures. Moreover, the residual carbon was investigated by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and scanning electron microscope (SEM), gas phase pyrolysis products were investigated by thermogravimetric analysis/infrared spectrometry (TG-IR) and thermogravimetric analysis/mass spectrometry (TG-MS). It was observed that the flame retardant mechanisms of the APP/AHP system was the combination of gas and condensed phase flame retardant mechanisms.

Preparation and characterization of oligomeric char forming agent and its effect on the thermal degradation and flame retardant properties of LDPE with ammonium polyphosphate**

An efficient oligomeric charring agent (CNCA-DA) containing a triazine and benzene rings was synthesized and characterized by the nuclear magnetic resonance spectroscopy (13C solid-state NMR), elemental analysis (EA) and thermal gravimetric analysis (TGA). The synergistic effects between Ammonium polyphosphate (APP) and CNCA-DA on the flame retardancy, thermal degradation and flame retardant mechanism of low density polyethylene (LDPE) were investigated. The 13C NMR and elemental analysis (EA) results indicated that the structure of CNCA-DA coincided with the expected design. The thermogravimetric analysis (TGA) analysis showed that CNCA-DA had a good char forming ability with a high initial temperature of thermal degradation. APP improved the char residue of the APP/CNCA-DA system with char residue reached 41.0% and 18.2at 600 and 700°C under air. The results from limited oxygen index (LOI) and vertical burning test (UL-94) showed that the intumescent flame retardant (IFR) was very effective in the flame retardancy of LDPE. When the mass ratio of APP and CNCA-DA was 2:1 with IFR loading at 30%, the LOI value of LDPE/IFR composite reached 30.9%. It was also found that when the IFR loading was only 25%, the flame retardancy of LDPE/IFR still passed V-0 rating in UL-94 tests with LOI value of 26.8%. The thermogravimetric analysis (TGA) and Thermogravimetric analyzer coupled to a mass spectrometer (TGA/MS) results indicated that IFR could reduce the thermal degradation rate at main stage of degradation and side chain fragmentation was probably the dominant mechanism of thermal degradation. The cone calorimeter teat test (CCT) results demonstrated that IFR clearly changed the decomposition behavior of LDPE and formed an intumescent char layer on the surface of the composites, subsequently resulting in the efficient reduction of the flammability parameters, such as the heat release rate (HRR), total heat release (THR), smoke production rate (SPR), total smoke production (TSP), mass loss (ML), CO production (COP) and CO2 production (CO2P). The morphological structures observed by digital photos and scanning electron microscopy (SEM) demonstrated that IFR promoted to form the continuous and compact intumescent char layer. The Fourier Transform infrared spectroscopy (FTIR), Laser Raman spectroscopy analysis (LRS) analysis results revealed that an appropriate graphitization degree and network structure of the residue char were formed to improve the strength and shield properties of the char layer to obtain better flame retardant properties of the composite.

Preparation, fire behavior and thermal stability of a novel flame retardant polypropylene system

In this study, a novel spirocyclic pentaerythritol bisphosphorate disphosphoryl-di-prop-2-en-1-amine (SPSA) compound containing a functional double bond (C=C) was synthesized and characterized by Fourier transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy (1H NMR). In this paper, a new intumescent flame retardant (IFR) was designed by combining ammonium polyphosphate (APP) and SPSA (mass ratio of APP and SPSA was 2:1) and this IFR was mixed with polypropylene (PP) via twin-screw extruder to prepare a series of flame retardant PP composites. The thermal stability and fire behaviors of these flame retardant PP composites were investigated by thermogravimetric analysis, limiting oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter test. Furthermore, the morphology of the char residues of flame retardant PP composites after cone calorimeter test was studied by scanning electron microscopy with energy dispersive X-ray analysis (EDS). Aiming to further improve the thermal stability of the composites, electron beam irradiation has been used to treat these composites. The results showed that LOI value of flame retardant PP composite containing 30 % IFR was 24.0 and passed UL 94 V-0. In the cone calorimeter test, both peak heat release rate and total heat release results of PP/IFR system were lower than those of PP/APP system. In addition, this IFR provided relatively good quality of char residue in the combustion. Moreover, electron beam treatment of the composites improved the thermal stability of these designed flame retardant PP composites.

Flame retardancy and thermal degradation of intumescent flame retardant EVA composite with efficient charring agent

Intumescent flame retardant ethylene-vinyl acetate (EVA) composites with ammonium polyphosphate (APP) and efficient charring agent (CNCA-DA) were prepared through melt blending. The effect of APP and CNCA-DA on the flame retardant properties and thermal degradation of EVA were investigated by the means of limited oxygen index (LOI), vertical burning test (UL-94), thermogravimetric analysis (TGA), cone calorimeter test (CCT), scanning electron microscopy (SEM), laser Raman spectroscopy (LRS), and Fourier transform infrared (FTIR). The results from LOI and UL-94 showed that the intumescent flame retardant (IFR) containing CNCA-DA and APP was very effective in flame retardancy of EVA. When the mass ratio of APP and CNCA-DA was 3:1, the IFR showed the best effect, and when the IFR loading held 30%, the LOI value reached 32.1%. It was also found that when the IFR loading held only 20%, the flame retardancy of EVAP/IFR can still pass V-0 rating in UL-94 tests, meanwhile, its LOI value reached 27.0%. As for CCT results, IFR could clearly change the decomposition behavior of EVA and formed an intumescent char layer on the surface of the composites, consequently resulting in efficient reduction of the flammability parameters, such as heat release rate (HRR), total heat release (THR), smoke production rate (SPR), and mass loss (ML). In addition, the morphological structures which were observed by digital photos and SEM manifested that IFR could promote to form the continuous and compact intumescent char layer. The analysis of LRS and FTIR indicated that EVA/IFR could form POP and POC connected structures as well as polyaromatic structure. When APP and CNCA-DA were combined together, the suitable strength of char layer was obtained to improve the flame retardant properties.

Preparation and characterization of a novel oligomeric charring agent and its application in halogen-free flame retardant polypropylene

A novel charring agent (CNCO-HA) containing triazine rings was synthesized by a series of polycondensation reactions, and characterized by Fourier transform infrared (FTIR), nuclear magnetic resonance spectroscopy (13C solid-state NMR), and thermal gravimetric analysis (TGA). The synergistic effects between APP and CNCO-HA on flame retardancy, thermal degradation, flammability properties and mechanism of polypropylene (PP) were investigated by the limited oxygen index (LOI), vertical burning test (UL-94), thermogravimetric analysis (TGA), cone calorimeter teat test (CCT), Laser Raman spectroscopy analysis (LRS) and Scanning electron microscopy (SEM). The TGA results showed that CNCO-HA had a good char forming ability, and a high initial temperature of thermal degradation; the char residue of CNCO-HA reached 36.2% and 6.2% at 600°C and 700°C under air; ammonium polyphosphate (APP) could improve the char residue of the APP/CNCO-HA system, the char residue reached 39.8% and 25.5% at 600°C and 700°C under air. The results from LOI and UL-94 showed that the intumescent flame retardant (IFR) containing CNCO-HA and APP was very effective in flame retardancy of PP. When the mass ratio of APP and CNCO-HA was 4:1, and the IFR loading was 30%, the IFR showed the best effect, and the LOI value reached 40.2%. It was also found that when the IFR loading was only 25%, the flame retardancy of PP/IFR could still pass V-0 rating in UL-94 tests, and its LOI value reached 34.3%. The CCT results demonstrated that IFR could clearly change the decomposition behavior of PP and form a char layer on the surface of the composites, consequently resulting in the efficient reduction of the flammability parameters, such as heat release rate (HRR), total heat release (THR), smoke production rate (SPR), total smoke production (TSP) and mass loss (ML). The morphological structures observed by digital photos and SEM demonstrated that IFR could be promoted to form the continuous and compact intumescent char layer. The LRS analysis results indicated that an appropriate graphitization degree of the residue char was formed to improve strength and shield properties of the char layer to obtain better flame retardant properties of the composite.

The fire-retardant properties of the melamine-modified urea–formaldehyde resins mixed with ammonium polyphosphate

Fire retardancy of melamine-modified urea–formaldehyde resin (MUF) containing intumescent fire-retardant ammonium polyphosphate (APP) (MUF/APP) was conducted by cone calorimeter with surface treatment of medium density fiberboard (MDF). The results showed that the six MUF resins synthesized with different F/(M + U) and M/U molar ratios containing APP significantly improved the fire retardancy of the MDF by prolonging ignition time, reducing heat release rate and total heat release, and decreasing mass loss rate. The fire-retardant properties of the six synthesized MUF/APP acted differently even though each MUF resin containing the same mass ratio of APP. The melamine content in the MUF should not be too high, otherwise it would decrease the fire-retardant properties of MUF/APP. Based on this study, the higher the APP amounts, the better the fire-retardant performance of the resin was. The fire retardancy of MUF/APP increased with the increase in the amount of glue that spread on the material surface. However, only the amount of glue spread exceeded 250 g/m2, whereas the ability of MUF/APP in inhibiting heat release did not increase significantly any longer.

Synthesis of novel triazine charring agent and its effect in intumescent flame‐retardant polypropylene

AbstractA novel charring agent (CNCA‐DA) containing triazine and benzene ring, using cyanuric chloride, aniline, and ethylenediamine as raw materials, was synthesized and characterized. The effects of CNCA‐DA on flame retardancy, thermal degradation, and flammability properties of polypropylene (PP) were investigated by limited oxygen index (LOI), vertical burning test (UL‐94), thermogravimetric analysis (TGA), and cone calorimeter test (CCT). The TGA results showed that CNCA‐DA had a good char forming ability, and a high initial temperature of thermal degradation; the char residue of CNCA‐DA reached 18.5% at 800°C; Ammonium polyphosphate (APP) could improve the char residue of APP/CNCA‐DA system, the char residue reached 31.6% at 800°C. The results from LOI and UL‐94 showed that the intumescent flame retardant (IFR) containing CNCA‐DA and APP was very effective in flame retardancy of PP. When the mass ratio of APP and CNCA‐DA was 2 : 1, and the IFR loading was 30%, the IFR showed the best effect; the LOI value reached 35.6%. It was also found that when the IFR loading was only 20%, the flame retardancy of PP/IFR can still pass V‐0 rating in UL‐94 tests, and its LOI value reached 27.1%. The CCT results demonstrated that IFR could clearly change the decomposition behavior of PP and form a char layer on the surface of the composites, consequently resulting in efficient reduction of the flammability parameters, such as heat release rate (HRR), total heat release (THR), smoke production rate (SPR), total smoke production (TSP), and mass loss (ML). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012