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9,10-Dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-N-Aminoethylpiperazine (DOPO-AEP), a phosphorus and nitrogen intumescent flame retardant curing agent was prepared by using acetonitrile as solvent using 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) and N-aminoethylpiperazine (AEP) as raw materials. The structure of the flame retardant curing agent DOPO-AEP was analyzed Fourier Transform Infrared Spectrometer (FTIR), Nuclear Magnetic Resonance (NMR) and Electrospray Ionization Mass Spectrometry (ESI-MS), and the synthesis method of the target product was determined. In addition, the content of char residue was determined by thermogravimetric analyzer, and its thermal properties were comprehensively explored, and based on the obtained results, the curable epoxy resin was selected to prepare DOPO-AEP/EP flame retardant composites. According to the amount of DOPO-AEP added product, different proportions of DOPO-AEP/EP flame retardant composites were prepared, and the actual impact of flame retardant properties and mechanical properties of epoxy resin in different proportions was explored. When the content of DOPO-AEP is 35%, the limiting oxygen index of DOPO-AEP/EP reaches 29.9, which has a significant increase compared with the limiting oxygen index of pure epoxy resin of 19.8, but compared with the content of DOPO-AEP of 30%, the limiting oxygen index of DOPO-AEP/EP is 28.7, and there is no significant increase change. Comprehensive analysis shows that when the component content of DOPO-AEP is 30%, the flame retardant system has a tensile strength of 29.0 MPa, an impact strength of 4.5Kj/m2 and a flexural strength of 73.9 MPa, and its limiting oxygen index is as high as 28.7, and the comprehensive performance of the system is the best. By testing the surface morphology of the flame retardant composites after combustion by SEM, it was found that a dense char layer was formed on the surface of the epoxy resin cured char residue and foamed obviously, indicating that the flame retardant curing performance of DOPO-AEP was good. [ABSTRACT FROM AUTHOR]

The polyester fabric was subjected to atmospheric plasma and impregnated with commercially available 3‐hydroxyphenyl phosphinyl‐propanoic acid (3HPP) as flame retarding agent by high‐temperature high pressure (HTHP) dyeing method. Various concentrations of 3HPP in water, up to 4% w/v, were applied using the HTHP method. It was observed that the plasma treatment not only enhanced wettability and wicking but also facilitated increased pickup of 3HPP onto the polyester. The treatment exhibited a noteworthy enhancement in the limiting oxygen index (LOI), rising from 20.8% for the untreated control fabric to 30% for the fabric treated with plasma and a 4% 3HPP solution. Additionally, the application of 3HPP without plasma treatment did not yield significant improvements in flame‐retardant (FR) properties. The combined treatment of plasma and 3HPP resulted in an LOI of 29% with a 2% 3HPP treatment, while at the same concentration without plasma treatment, the LOI value was 26.8%. The heightened LOI was primarily attributed to the presence of phosphorus, as confirmed by high‐performance liquid chromatography and energy‐dispersive X‐ray spectroscopy. Additionally, the wash durability assessment of plasma‐processed and 3HPP‐treated samples demonstrated sustained flame retardancy, with an LOI of approximately 28% even after undergoing 20 wash cycles. Vertical flammability and cone calorimetry also confirm improved FR properties after treatment. Remarkably, the mechanical properties and surface morphology of the fabric remained unaltered following both plasma and chemical treatments. Highlights: Easy and cost‐effective technique for the downstream process for FR polyester fabric.FR agent during polymerization has the disadvantage of lower molecular weight.Potential for producing FR industrial polyester fabric.Post‐plasma treatment improves the washing fastness.The mechanical and comfort properties remain intact during the process. [ABSTRACT FROM AUTHOR]

This research paper comprises of application of a flame-retardant finish on the Varanasi brocade pineapple fabric. The novel technique can impart durable flame retardancy. Ammonium polyphosphate (APP) was used as an intumescent flame-retardant polymer to impart flame retardancy. An investigation on the optimization of APP solution concentration has been made. The fabric characterization for the final product's flame-retardant property after the application is presented. The treated fabric has shown increased LOI values with increasing concentrations of APP up to a specific limit. The LOI of 36.7% was determined at a 15% solution concentration. The SEM images showed APP's presence on the pineapple fibers' surface, and the EDX analysis of fabric samples confirmed the elemental addition of nitrogen and phosphorous in the treated fabric. FTIR analysis of control and treated fabric confirms the P-O-C covalent bonding between fiber and APP. TGA analysis of samples has shown the treated samples' low thermal degradation and weight loss compared to control. VFT test showed increased char length and no after-flame time for 15% APP-treated pineapple fabric. Cone calorimetric analysis confirmed that PHRR decreased by around 98% while ARHE and THRR decreased by 49.56% and 50% after 15% of APP treatment. Images of samples after cone calorimetric analysis have presented the layer of char formation in treated fabric. LOI > 25 was retained after 20 home laundering of the treated fabric. And no significant effect of APP was found on the colorimetric values of dyed pineapple fabric. [ABSTRACT FROM AUTHOR]

Polyethylene terephthalate (PET) foams have the characteristics of being lightweight and high strength, as well as offering good heat resistance, minimal water absorption, etc., and they have been widely used in the wind power field. In addition, they are being promisingly applied in automotive, rail, marine, construction, and other related fields. Therefore, the flame retardancy(FR) of PET foams is an issue that requires investigation. The addition of flame retardants would affect the chain extension reaction, viscoelasticity, and foamability of PET. In this study, zinc diethyl hypophosphite (ZDP) and decabromodiphenylethane (DBDPE) were used to form a synergistic FR system, in which ZDP is an acid source and DBDPE is a gas source, and both of them synergistically produced an expanded carbon layer to improve the flame retardancy of PET foams. The ratio of ZDP and DBDPE is crucial for the carbon yield and the expansion and thermal stability of the char layers. At the ZDP/DBDPE ratios of 9/3 and 7/5, the thickness of the char layers is about 3–4 mm, the limiting oxygen index (LOI) values of FR modified PET are 32.7% and 33.6%, respectively, and the vertical combustion tests both reached the V-0 level. As for the extruded phosphorous/bromine synergism FR PET foams, ZDP/DBDPE ratios of 3:1 and 2:1 were applied. As a result, the vertical combustion grade of foamed specimens could still reach V-0 grade, and the LOI values are all over 27%, reaching the refractory grade. [ABSTRACT FROM AUTHOR]

To solve the problems of low flame retardant performance in the use of acrylic resin, a flame-retardant acrylic resin coating PA-IFR was prepared by adding intumescent flame retardants (IFR) composed of ammonium polyphosphate (APP), pentaerythritol (PER) and melamine (MEL) to the acrylic resin emulsion by combining ultrasonic and mechanical stirring. The chemical structure, transmittance, hardness and flame retardant properties of PA-IFR were tested by infrared spectrometer, X-ray diffractometer, pencil hardness tester and limiting oxygen index meter. The results show that the hardness of the PA-IFR reaches 5H and the limiting oxygen index (LOI) value reaches 32.6% when the mass fraction of the FR is 30% and the formula ratio of APP/PER/MEL is 2 : 1 : 1. The acrylic resin coating prepared in this study is a flame retardant material. [ABSTRACT FROM AUTHOR]

In this study, novel durable flame-retardant lyocell fibres were designed by the addition of phosphorylated cellulose and physical blending of montmorillonite (MTT) within the fibres. The influences of phosphorylation and MTT blending on the flame retardancy of lyocell fibres were investigated. Additionally, the synergistic effects of the two flame retardant methods were also discussed. Furthermore, phosphorylated cellulose and MTT-filled lyocell fibres were prepared, and their flame retardancy was measured. Phosphorylation (limiting oxygen index (LOI) > 28%) was found to improve the flame retardancy of the lyocell fibres; nevertheless, excessive phosphorylation decreased the crystallinity of the cellulose and decreased the mechanical strength of the fibres. Montmorillonite was added to the lyocell fibres to achieve durable flame retardancy, whereas the LOI was less than 24%. Interestingly, lyocell fibres with LOIs greater than 28% and strengths greater than 2.0 cN/dtex could be obtained from the phosphorylated cellulose with MTT filling. The thermogravimetric (TG) and TG-infrared (TG-IR) experimental results showed that MTT played a role in the condensed-phase flame retardancy, while phosphorylated cellulose played a role in the gas-phase and condensed-phase flame retardancy. The Raman test results showed that the combination of MTT and phosphorylated cellulose enhanced the graphitization degree of the residue char. In our study, a novel flame-retardant method for the preparation of lyocell fibres with permanent flame retardancy and high tensile strength was developed; moreover, our results contribute to the development of industrial-grade fabrication of new flame-retardant fibre materials. [ABSTRACT FROM AUTHOR]

Herein, nano boron nitride (BN) laminated poly(ethyl methacrylate) (PEMA)/poly(vinyl alcohol) (PVA) nanocomposite films are fabricated by using a simple in situ polymerization technique with incorporation of silver nanoparticles (Ag NPs). Structural investigations of PEMA/PVA/Ag@BN nanocomposite thin films are carried out by Fourier‐transform infrared spectroscopy, dynamic light scattering, X‐ray diffraction analysis, 1H nuclear magnetic resonance, 13C nuclear magnetic resonance, and mass spectrometry. The change in morphology of PEMA/PVA matrix due to the reinforcement of BN platelets are identified by electron microscopic studies. The unique tortuous paths are achieved by the dispersion of BN platelets by which gas penetration is restricted with enhancing the barrier properties of the material by 6.5 folds at 5 wt% BN content as compared with neat PEMA/PVA. Acid and alkali resistant along with biodegradability behavior of as‐synthesized nanocomposites are studied. From limiting oxygen index (LOI) results, it is found that the prepared materials are fire retardant in nature owing to effective reinforcement of BN layers. Antibacterial activities of PEMA/PVA/Ag@BN nanocomposite are studied by Xanthomonas citri or axonopodis pv. Citri, Escherichia coli, and Xanthomonas oryzae pv. Oryzae because of Ag NPs reinforcement. The substantial improvements in gas barrier, fire retardant, and antibacterial properties enable the materials for packaging application. [ABSTRACT FROM AUTHOR]

Halogen-free organophosphorus flame retardants have promising application prospects due to their excellent safety and environmental protection properties. A cobalt-coordinated cyclic phosphonitrile flame retardant (Co@CPA) was synthesized via a hydrothermal method using hexachlorocyclotriphosphonitrile (HCCP), 5-amino-tetrazolium (5-AT), and cobalt nitrate hexahydrate (Co(NO3)2∙6H2O) as starting materials. The structure was characterized using Fourier transform infrared (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Thermoplastic polyurethane (TPU) composites were prepared by incorporating 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphame-10-oxide (ODOPB), Co@CPA, and silicon dioxide (SiO2) via melt blending. The flame-retardant performance and thermal stability of the TPU composites were evaluated through limiting oxygen index (LOI), vertical combustion (UL-94), TG, and cone calorimetric (CCT) tests. SEM and Raman spectroscopy were used to analyze the surface morphology and structure of the residual carbon. A synergistic flame-retardant effect of ODOPB and Co@CPA was observed, with the most effective flame retardancy achieved at a TPU:ODOPB:Co@CPA:SiO2 ratio of 75:16:8:1. This composition exhibited an LOI value of 26.5% and achieved a V-0 rating in the UL-94 test. Furthermore, compared to pure TPU, the composite showed reductions in total heat release, CO production, and CO2 production by 6.6%, 39.4%, and 48.9%, respectively. Our research findings suggest that Co@CPA demonstrates outstanding performance, with potential for further expansion in application areas. Different metal-based cyclic phosphonitrile compounds are significant in enriching phosphorus-based fine chemicals. [ABSTRACT FROM AUTHOR]

Ethylene‐propylene‐diene monomer (EPDM) rubber has widespread uses in various applications due to its ozone and oxidation stability, weatherability, electrical insulation, and elasticity. However, its further use is limited by low flame retardancy and low thermal stability. This study incorporated metal hydroxide flame retardant to enhance flame retardancy and electron beam cross‐linking to simultaneously enhance mechanical properties, thermal stability, and flame retardancy. The utilization of electron beam irradiation resulted in an increase in gel content and a decrease in swelling ratio with increasing absorbed doses, indicating the successful formation of cross‐linked network structures. The hot‐set elongation was significantly reduced to 0.6%–0.8%, while the decomposition temperature increased with increasing absorbed doses, indicating improved thermal stability. The results from limiting oxygen index measurements and burning tests demonstrate that the flame retardancy of EPDM was improved by the combined effect of metal hydroxide flame retardant and electron beam cross‐linking. Highlights: EPDM/metal hydroxide composites were prepared via electron beam irradiation.Metal hydroxide flame retardants were incorporated to enhance flame retardancy.EBI simultaneously enhanced mechanical property and thermal stability. [ABSTRACT FROM AUTHOR]

In order to study the combustion characteristics of glass fiber/phenolic resin composites, a conical calorimeter was used to explore the combustion characteristics of glass fiber/phenolic resin composites in an aircraft frame under different thermal radiation intensities, and the fire hazard of the materials was evaluated by evaluation index, and the limiting oxygen index at different temperatures was explored by combining the high temperature oxygen index meter. The test results show that when the ambient temperature increases from 20 °C to 220 °C, the limiting oxygen index first increases from 86.6 % to 93.7 %, and then decreases to 84.4 %. The oxygen consumption and CO2 release increase with the increase of thermal radiation intensity during combustion, and the release of CO decreases with the increase of thermal radiation. The heat release rate curve of the test material has only 1 enhancement peak. The heat radiation intensity increased from 50 kW/m2 to 70 kW/m2, and the peak heat release rate of the test material combustion increased from 64.7 kW/m2 to 100.7 kW/m2. The rate of mass loss of materials accelerates with the increase of thermal radiation intensity; As the intensity of thermal radiation increases, the fire hazard of the material increases.

The aim of this study was to investigate the physical properties of yarns made with different blend ratios of meta-aramid, para-aramid, flame-resistant (FR) viscose, and antistatic nylon fibers, as well as the tensile strengths and burning behaviors of fabrics made from these yarns. For this purpose, 10 different yarns of two different linear densities were produced using five different blend ratios, which are commonly used in the production of fire-resistant fabrics, and knitted fabrics were produced from these yarns, with the same knitting machine and the same production parameters. Physical properties of the yarns and tensile properties and burning characteristics of the knitted fabrics were measured according to commonly applied standards, and the results obtained were evaluated using the SPSS statistical program. The findings of this study are that the blend ratios of meta-aramid, para-aramid, FR viscose, and antistatic nylon fibers have statistically significant effects on the unevenness, humidity, and tenacity of the yarns, as well as on the tensile properties and burning characteristics of the fabrics. It was found that, with an increase of the aramid fiber ratio in the blend, the tensile values of the yarns and fabrics increased. The lowest moisture contents were recorded for 100% para-aramid yarns but the highest moisture contents were recorded for yarns whose blends contained FR viscose fibers. The yarns whose blends contained antistatic nylon fibers exhibited the greatest unevenness and the most thin and thick places and neps. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Polyethylene terephthalate (PET) foams have the characteristics of being lightweight and high strength, as well as offering good heat resistance, minimal water absorption, etc., and they have been widely used in the wind power field. In addition, they are being promisingly applied in automotive, rail, marine, construction, and other related fields. Therefore, the flame retardancy(FR) of PET foams is an issue that requires investigation. The addition of flame retardants would affect the chain extension reaction, viscoelasticity, and foamability of PET. In this study, zinc diethyl hypophosphite (ZDP) and decabromodiphenylethane (DBDPE) were used to form a synergistic FR system, in which ZDP is an acid source and DBDPE is a gas source, and both of them synergistically produced an expanded carbon layer to improve the flame retardancy of PET foams. The ratio of ZDP and DBDPE is crucial for the carbon yield and the expansion and thermal stability of the char layers. At the ZDP/DBDPE ratios of 9/3 and 7/5, the thickness of the char layers is about 3–4 mm, the limiting oxygen index (LOI) values of FR modified PET are 32.7% and 33.6%, respectively, and the vertical combustion tests both reached the V-0 level. As for the extruded phosphorous/bromine synergism FR PET foams, ZDP/DBDPE ratios of 3:1 and 2:1 were applied. As a result, the vertical combustion grade of foamed specimens could still reach V-0 grade, and the LOI values are all over 27%, reaching the refractory grade.

A highly dispersed melamine cyanuric acid (MCA) dispersion with N-methylmorpholine- N-oxide ( NMMO ) aqueous solution as the dispersion medium was prepared using a wet grinding process to address the issues of blockage, wire breakage and flame retardant precipitation in the production process of flame retardant Lyocell fibers using the blending method. The prepared MCA dispersion was used as the flame retardant to prepare flame retardant Lyocell fibers. The stability of MCA dispersion particle size and pH stability, the distribution characteristics of MCA in the spinning solution, the effects of particle size and surface additive content of MCA dispersion on fiber spinnability, thermal stability, mechanical properties and flame retardancy of flame retardant Lyocell fibers were analyzed using laser particle size analyzer, optical microscope, scanning electron microscope, fiber size analyzer, thermogravimetric analyzer, limiting oxygen index analyzer and other equipment. The results show that the particle size and pH value of MCA dispersion have no change. The dissolution degree and dissolution rate of MCA in the spinning solution significantly increase under stirring and vacuum conditions; The particle size of MCA dispersion and the content of surface additives have a significant impact on the spinnability of fibers. For example, when the particle size D90 is 0.5 µm (90% of the particles have a diameter less than 0.5 µm), and the content of surface additives accounts for 6% of the flame retardant, there are no problems such as blocking, fiber breakage, and a large amount of flame retardant precipitation in the coagulation bath during the spinning process; When the MCA content accounts for 40% of the weight of Lyocell fibers, the fibers exhibit good mechanical properties, flame retardancy, and washing resistance. The highest inechanical strength is 2.76 cN/dtex, and the limiting oxygen index (LOI) is 33. 3%. After 12 machine washes, the LOI value of the fibers remains above 30%; In addition, the initial decomposition temperature of the prepared flame retardant Lyocell fiber was significantly increased compared to ordinary Lyocell fibers, and the residual carbon content of cellulose in the fiber (about 24.03%) was higher than that of non flame retardant fibers (about 16.53%) . [ABSTRACT FROM AUTHOR]

Due to the strict working environment, insulating paper is generally required to have a good flame retardant performance. In this study, a new type of starch‐based synergistic flame retardant (SPBD) is prepared using starch as a carbon source, phytic acid, and boric acid as the acid source, and dicyandiamide as a gas source by the one‐pot method. The flammability, mechanical, and electrical properties of the flame‐retardant insulating papers treated with SPBD are also studied. When the concentration of the SPBD is 24.0%, the limiting oxygen index of the insulating paper is increased from 19.4% to 44.0% and reaches the level of UL‐94 V0. The tensile index and burst index of the flame‐retardant insulating papers are only 6.88% and 10.75% lower than that of the control insulating paper. While the ring crush strength and alternating current (AC) breakdown strength in air are 109.58% and 21.15% higher than the control insulating paper. The SPBD flame retardant has a good application prospect in insulating paper. [ABSTRACT FROM AUTHOR]

Halogen-free organophosphorus flame retardants have promising application prospects due to their excellent safety and environmental protection properties. A cobalt-coordinated cyclic phosphonitrile flame retardant (Co@CPA) was synthesized via a hydrothermal method using hexachlorocyclotriphosphonitrile (HCCP), 5-amino-tetrazolium (5-AT), and cobalt nitrate hexahydrate (Co(NO3)2∙6H2O) as starting materials. The structure was characterized using Fourier transform infrared (FTIR), nuclear magnetic resonance spectroscopy (1H-NMR), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Thermoplastic polyurethane (TPU) composites were prepared by incorporating 10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phosphame-10-oxide (ODOPB), Co@CPA, and silicon dioxide (SiO2) via melt blending. The flame-retardant performance and thermal stability of the TPU composites were evaluated through limiting oxygen index (LOI), vertical combustion (UL-94), TG, and cone calorimetric (CCT) tests. SEM and Raman spectroscopy were used to analyze the surface morphology and structure of the residual carbon. A synergistic flame-retardant effect of ODOPB and Co@CPA was observed, with the most effective flame retardancy achieved at a TPU:ODOPB:Co@CPA:SiO2 ratio of 75:16:8:1. This composition exhibited an LOI value of 26.5% and achieved a V-0 rating in the UL-94 test. Furthermore, compared to pure TPU, the composite showed reductions in total heat release, CO production, and CO2 production by 6.6%, 39.4%, and 48.9%, respectively. Our research findings suggest that Co@CPA demonstrates outstanding performance, with potential for further expansion in application areas. Different metal-based cyclic phosphonitrile compounds are significant in enriching phosphorus-based fine chemicals.

The flammability of various materials used in industry is an important issue in the modern world. This work is devoted to the study of the effect of flame retardants, graphene and DDM-DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-4,4′-diamino-diphenyl methane), on the flammability of glass-fiber-reinforced epoxy resin (GFRER). Samples were made without additives and with additives of fire retardants: graphene and DDM-DOPO in various proportions. To study the flammability of the samples, standard flammability tests were carried out, such as thermogravimetric analysis, the limiting oxygen index (LOI) test, and cone calorimetry. In addition, in order to test the effectiveness of fire retardants under real fire conditions, for the first time, the thermal structure of downward flame propagation over GFRER composites was measured using thin thermocouples. For the first time, the measured thermal structure of the flame was compared with the results of numerical simulations of flame propagation over GFRER. [ABSTRACT FROM AUTHOR]

Thermal behavior and fire reaction properties of aerial glass fiber (GF)/bismaleimide (BMI) composites were tested using thermogravimetric analysis (TGA), thermogravimetric coupled with Fourier transform infrared spectroscopy (TG-FTIR), cone calorimeter, limiting oxygen index, and smoke density chamber. The results showed that the pyrolysis process was one stage in a nitrogen atmosphere with the prominent volatile components of CO2, H2O, CH4, NOx, and SO2. The release of heat and smoke increased with the increase in heat flux, while the time required to reach hazardous conditions decreased. The limiting oxygen index decreased monotonically from 47.8% to 39.0% with increasing experimental temperature. The maximum specific optical density within 20 min in the non-flaming mode was greater than that in the flaming mode. According to the four kinds of fire hazard assessment indicators, the greater the heat flux, the higher the fire hazard, for the contribution of more decomposed components. The calculations of two indices confirmed that the smoke release in the early stage of fire was more negative under flaming mode. This work can provide a comprehensive understanding of the thermal and fire characteristics of GF/BMI composites used for aircraft. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The automotive industry has benefited greatly from the advancements in fireproof, high-strength fiber-reinforced polymer matrix composites during the last several decades. S-Glass/Phenolic hybrid composites made by hydraulic compression molding are the subject of this investigation into the effects of Melamine Polyphosphate (MPP) on their thermal and fire performance. In addition to studying the morphology of the samples, researchers analyzed the thermal and fire performances of hybrid laminates made with neat laminates and varying compositions of MPP (ranging from 3% to 15% by weight). Tests included UL 94, limiting oxygen index (LOI), and the impacts of accelerated heat ageing on the behavior of the hybrid specimens. The results demonstrated that specimens filled with higher MPP performed better in a fire compared to neat samples. According to the results in UL 94 horizontal burning test and vertical burning test, specimens filled with 12 and 15 wt. % MPP demonstrated a reduced flame spreading rate and fulfilled the V-0 criteria. Simultaneously, the energy absorption capacity of hybrid configurations is severely limited by heat ageing, due to its temperature and duration dependent. The research proved that the suggested S-Glass / Phenolic / Melamine Polyphosphate hybrid composites were suitable for creating environmentally friendly electric vehicle battery housings and fire-resistant automotive parts.

Unrecyclable industrial rockwool fiber waste is a worldwide problem that demands an effective yet sustainable solution. This paper presents a work on repurposing industrial rockwool fiber wastes as fillers for rigid polyurethane (PU) foam. The fillers are varied from 1 to 10 wt% and the obtained reinforced foams are characterized for their thermal stability, combustibility, foam morphology, and mechanical response. Marked improvement in thermal stability was observed in the presence of rockwool inside the foam formulation as denoted by delayed thermal degradation temperatures. Unfortunately, a similar finding was not obtained for its fire-retardancy as no distinguishable differences in Limiting Oxygen Index (LOI) and UL-94 combustion test was observed. Microscopy imaging indicated reduced cell size with increased filler loading, and the rockwool fillers are homogenously scattered within the polymer matrix. Drop in normalized compressive properties was detected, suggesting rockwool fillers pose no mechanical reinforcing effect on the foam other than through increased apparent foam and cellular density. [ABSTRACT FROM AUTHOR]

In this paper, we report a method of preparation of ambient temperature curable phosphorous containing epoxy resin‐based composites and their flame retardant behavior. The phosphorous containing resin, prepared by reacting the epoxy resin with 9,10‐Dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO), shows higher limiting oxygen index (LOI) in the cured state compared to the pure epoxy network. The LOI value is further enhanced due to the incorporation of phosphorous‐containing silica, although the same remains unchanged when pure silica is added. The composites made with phosphorous‐containing resin and pure silica exhibits UL‐94 V‐1 class rating whereas the same made with phosphorous‐containing silica offers V‐0 rating under UL‐94 classification. This observation clearly indicates that the performance is enhanced when phosphorous in incorporated in the resin as well as in the inorganic reinforcing filler. [ABSTRACT FROM AUTHOR]

In this study, various blended fabrics of modacrylic fibre with flame retardant (FR) viscose, and Nylon 66 have been manufactured and studied for their thermal, mechanical and comfort properties for workers of oil & gas industry. The ring spinning system is used to manufacture three sets of yarns. In the first set, three yarns are produced using only modacrylic, only FR viscose, and only Nylon 66 fibres. The second set of yarns is made using blends of FR viscose and modacrylic. These fibres are blended in three different ratios of 30:70, 50:50 and 70:30 for making yarns. The third set is made out of tertiary blends of FR viscose, nylon 66 and modacrylic. These are blended in two different ratios of 30:20:50 and 50:20:30 respectively. Fabric samples have been produced out of these yarns and evaluated for their flame, thermal and mechanical properties after 5 and 50 washes. The radiant heat transfer index and convective heat transfer index of blends of modacrylic fibre are found in the range 12 - 13.5 s and 5.0 - 5.7 s respectively. Multivariate test analysis has been applied to find out the effect of different fibre blends on various flame and thermal properties. The study shows that flame and thermal resistant properties are influenced by fibre blending ratio. [ABSTRACT FROM AUTHOR]

In this study, photocurable monomers containing phosphorus–nitrogen groups were employed alongside UV curing technology to develop flame-retardant (FR) coatings pouch-type battery cells made from polyethylene terephthalate (PET). Three different monomers were synthesized: a phosphorus-containing urethane acrylate monomer (DUPPO), a phosphorus–nitrogen-containing urethane acrylate monomer (DA-Pi-U), and a phosphazene-containing phenyl methacrylate crosslinker (CP-PMA). These monomers, recognized for their flame-retardant properties, were utilized in binary and ternary coating formulations that were effectively cured via a UV-curing process. The molecular architectures of the synthesized monomers were verified through 1H and 31P nuclear magnetic resonance spectroscopy. The rheological curing behavior of the coating solutions was assessed using an oscillatory rheometer. In addition, the reactivity of the FR coating system was examined via Fourier transform infrared spectroscopy. The thermal and flame-retardant characteristics of the FR coatings were confirmed through thermogravimetric analysis, Raman spectroscopy, limiting oxygen index measurements, and scanning electron microscopy. The ternary FR coating system with CP-PMA exhibited superior thermal stability, flame retardancy, crosslinking density, and mechanical robustness, making it suitable for PET pouches. Furthermore, optimal coating conditions for the slot coating process were determined using a viscocapillary model, enhancing practical applicability in industrial settings. • Novel phosphorus–nitrogen (P N) monomerswere synthesized and characterized for use as flame-retardant coatings. • Ternary FR coatings exhibited enhanced thermal stability and robust self-extinguishing properties through P–N-based flame-retardant monomers. • Enhanced flame retardancy were demonstrated in the ternary FR coatings, reflecting potential for use in safety applications. [ABSTRACT FROM AUTHOR]

Two flame retardants, melamine polyphosphate (MPP) and modified melamine cyanurate (MCA), were examined and added to a cellulose solution to fabricate flame‐retardant Lyocell fibers Lyocell‐MPP and Lyocell‐MCA, respectively, via dry–wet spinning. Compared with the non‐modified Lyocell fiber (without flame retardant), the flame‐retardant fibers produced a higher amount of carbon residue during combustion, whereas the heat release capacity, peak heat release rate, and total heat release decreased, indicating that the flame‐retardant fibers present a lower fire risk. The limit oxygen index values of Lyocell‐MPP and Lyocell‐MCA were 26.5% and 27.1%, respectively, complying with the flame‐retardant standard. The crystallinity and mechanical properties of the flame‐retardant fibers decreased relative to those of the non‐modified Lyocell fiber. Furthermore, the wearability of the flame‐retardant fibers was studied—both flame‐retardant fibers displayed good washing resistance properties and improved hygroscopicity but a lower dyeing performance than the non‐modified Lyocell fiber. [ABSTRACT FROM AUTHOR]

Application and development status of flame retardant fiber in automotive interior materials were discussed. Importance of using flame retardant fiber in automotive interior material was expounded. Flame retardant mechanism and types of flame retardant fibers, application research of flame retardant fiber in automotive interior were reviewed. It is considered that relying on joint support of chemical technology, polymer technology and textile technology, it is the future research and development direction to develop flame retardant automotive interior materials with better flame retardant property, reasonable price, functional composite, green and high-tech. [ABSTRACT FROM AUTHOR]

Long-chain bio-based polyamide has shown promising development prospects due to its excellent properties and green renewable characteristics; however, synthesizing inherently flame-retardant long-chain bio-based polyamide remains a big challenge due to the lack of effective knowledge of the key polymerization process. Herein, intrinsicly flame-retardant long-chain bio-based polyamide 512 (PA512) was synthesized in the presence of a reactive flame retardant with high thermal stability and good water solubility. The reaction conditions and existing problems in each stage of the copolymerization system have been clarified and optimized. By utilizing a two-step pre-polymerization approach, a series of intrinsicly flame-retardant PA512 (FRPA512) with large molecular weight, high phosphorus element content and good mechanical properties were obtained. More importantly, the prepared FRPA512 with 5 wt % flame retardant loading exhibited good flame retardancy, showing a limiting oxygen index (LOI) of 28.1 % and a vertical burning rating of V-0. This study provides a feasible solution to the common problem in the synthesis of flame-retardant polyamides, while also offering new insights for future modification of polyamide copolymerization., (© 2024 Wiley-VCH GmbH.)

The flammability of various materials used in industry is an important issue in the modern world. This work is devoted to the study of the effect of flame retardants, graphene and DDM-DOPO (9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide-4,4′-diamino-diphenyl methane), on the flammability of glass-fiber-reinforced epoxy resin (GFRER). Samples were made without additives and with additives of fire retardants: graphene and DDM-DOPO in various proportions. To study the flammability of the samples, standard flammability tests were carried out, such as thermogravimetric analysis, the limiting oxygen index (LOI) test, and cone calorimetry. In addition, in order to test the effectiveness of fire retardants under real fire conditions, for the first time, the thermal structure of downward flame propagation over GFRER composites was measured using thin thermocouples. For the first time, the measured thermal structure of the flame was compared with the results of numerical simulations of flame propagation over GFRER.

Efforts have been devoted to synthesize and characterize processable polymers with desired properties. Herein, four different series of aromatic and aliphatic terpolyamides were prepared via solution phase polycondensation of 4,4′-oxydianiline and hexamethylenediamine (HMDA) with various diacids chlorides (isophthalyol dichloride, terepthalyol dichloride, 1, 1′-ferrocene dicarboxylic acid chloride and trans-azobenzene-4, 4′-dicarbonyl chloride). The structural, morphological and physico-chemical nature of as prepared polymers was explored by Fourier-transform infrared spectroscopy, scanning electron microscopy, thermal analysis (TGA and DSC), and wide-angle x-ray diffraction. Moreover, an aliphatic diamine was incorporated in varying concentration as a flexible methylene spacer and the effect of its concentration on the properties of polyamides was also studied. Changes in various physico-chemical properties such as solubility, inherent viscosity, surface morphology and flame retarding behaviour were investigated. Marked difference in morphology and solubility was observed with the change in the ratio of segments in the chain. Inherent viscosities of polymers ranged from 1.8052–1.6274 dl/g indicating reasonably moderate molecular weights. Interestingly, ferrocene based aromatic polymers were more thermally stable (Tg 260 °C, Ti 310 °C, Th 525 °C, Tf 720 °C, for PF0), and also found to exhibit best flame retarding behavior (limiting oxygen index value for PF0is LOI 33.15%). [ABSTRACT FROM AUTHOR]

Thermal behavior and fire reaction properties of aerial glass fiber (GF)/bismaleimide (BMI) composites were tested using thermogravimetric analysis (TGA), thermogravimetric coupled with Fourier transform infrared spectroscopy (TG-FTIR), cone calorimeter, limiting oxygen index, and smoke density chamber. The results showed that the pyrolysis process was one stage in a nitrogen atmosphere with the prominent volatile components of CO2, H2O, CH4, NOx, and SO2. The release of heat and smoke increased with the increase in heat flux, while the time required to reach hazardous conditions decreased. The limiting oxygen index decreased monotonically from 47.8% to 39.0% with increasing experimental temperature. The maximum specific optical density within 20 min in the non-flaming mode was greater than that in the flaming mode. According to the four kinds of fire hazard assessment indicators, the greater the heat flux, the higher the fire hazard, for the contribution of more decomposed components. The calculations of two indices confirmed that the smoke release in the early stage of fire was more negative under flaming mode. This work can provide a comprehensive understanding of the thermal and fire characteristics of GF/BMI composites used for aircraft.

The growing importance of electric mobility has led to an increased demand for safety technologies in the automotive sector, such as the flame retardancy of materials used for electric vehicles. The fire protection of a fully equipped rechargeable energy storage system (REESS), including battery, housing, control electronics, etc., against a fuel fire must be tested according to UNECE Regulation No. 100 Annex 8E ‐ Fire Resistance (UNECE‐R100‐8E). To pass this fire retardancy requirement, the flame retardancy of the housing materials is of great importance. In this study, the flame retardancy of glass‐fiber‐reinforced polypropylene (PP‐GF) tape laminates containing the flame retardant magnesium hydroxide and different GF amounts, as well as sandwich structures of these PP‐GF tape laminates with a polypropylene bead foam (EPP) core, are investigated by a limiting oxygen index test, a UL94 test and a cone calorimeter test. Furthermore, a newly developed approach of a bench‐scale fuel fire test which simulates the fire treatment of the UNECE‐R100‐8E on component level is used. [ABSTRACT FROM AUTHOR]

Copyright of China Sciencepaper is the property of China Sciencepaper and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Two types of structurally different benzoxazines (BF-abn and BZ-abn) have been developed using bisphenol-F and bisphenol-Z with 4-aminobenzonitrile and paraformaldehyde through Mannich condensation reaction under an appropriate experimental conditions. Molecular structure of benzoxazine was confirmed by FTIR and 1H-NMR spectral analyses. Cure behavior and thermal stability were studied using differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) respectively. The results from DSC analysis indicated that these benzoxazines exhibit marginally lower polymerization temperature than that of conventional benzoxazines. Further, the curing behavior of both benzoxazine samples were studied at two different heating rates viz. 10 °C/min and 20 °C/min to ascertain their heat releasing properties. The formation of polybenzoxazine was confirmed by FTIR analysis after the thermal curing through the cleavage of benzoxazine ring and subsequently led to the formation of three dimensional cross-linked network structure. Results from TGA infers that among the benzoxazines studied, poly(BF-abn) possess better thermal stability than that of poly(BZ-abn). Further, the values of LOI calculated using char yield obtained at 850 °C from TGA for poly(BF-abn) and poly(BZ-abn) are 41% and 30% respectively. The values of water contact angle obtained for poly(BF-abn) and poly(BZ-abn) are 138° and 140° respectively. Both benzoxazine samples exhibit an excellent hydrophobic behavior. [ABSTRACT FROM AUTHOR]

Epoxy resins (EPs) require the addition of flame retardants to extend their application scope. High-efficiency flame retardants typically contain halogens, which can cause tremendous harm to humans and the environment. In this study, we investigated the syntheses of new phosphorus–nitrogen flame retardants (DIT) and flame-retardant EP. DIT is composed of 6-(2,5-dihydroxyphenyl) dibenzo[c,e][1,2] oxaphosphinine 6-oxide, 5-isocyanato-1-(isocyanatomethyl)−1,3,3-trimethylcyclohexane, and tris-(2-hydroxyethyl) isocyanurate. DIT chemical structure was analysed by Fourier-transform infrared spectroscopy. Several formulations of modified epoxy resins (DIT-EPs) were obtained by adding different quantities of DITs. We found that when the flame retardant content reached 25%, the limiting oxygen index of the DIT-EP was 29.0%. This finding expands the application range of EPs.

Environmentally friendly flame retardant chemicals are being developed in recent studies as legislation for eco-sustainable textile production becomes more stringent around the world. Utilisation of waste generated by the wool spinning industry is a prime concern with present work. The extraction and modification of keratin from waste wool for flame retardant cotton has not been attempted previously. The research describes a unique method for using chemically modified keratin derived from wool waste as an environmentally acceptable nitrogen/phosphorus containing flame retardant for cotton fabrics. Melamine and sodium pyrophosphate were used as nitrogen and phosphorus sources, respectively, along with glyoxal as a cross-linking agent. The improved thermal stability of modified wool waste keratin and treated cotton fabrics was confirmed by TGA, while structural changes were established by FTIR and XRD analyses. Due to the synergistic impact of nitrogen and phosphorous, the modified wool waste keratin resulted in the formation of a continuous and intact layer of char that confers flame retardancy on treated cotton. The limiting oxygen index of cotton after application of the modified keratin showed a nearly 66.7% increase in flame retardancy compared to untreated cotton. Overall, the findings in the paper show a sustainable approach for the textile industry that combines waste utilisation from one textile sector (minimizing solid waste from the wool industry) with waste management elements to add value to another (multifunctional textile finishing agent for the cotton industry).

In order to study the combustion characteristics of glass fiber/phenolic resin composites, a conical calorimeter was used to explore the combustion characteristics of glass fiber/phenolic resin composites in an aircraft frame under different thermal radiation intensities, and the fire hazard of the materials was evaluated by evaluation index, and the limiting oxygen index at different temperatures was explored by combining the high temperature oxygen index meter. The test results show that when the ambient temperature increases from 20 °C to 220 °C, the limiting oxygen index first increases from 86.6 % to 93.7 %, and then decreases to 84.4 %. The oxygen consumption and CO 2 release increase with the increase of thermal radiation intensity during combustion, and the release of CO decreases with the increase of thermal radiation. The heat release rate curve of the test material has only 1 enhancement peak. The heat radiation intensity increased from 50 kW/m 2 to 70 kW/m 2 , and the peak heat release rate of the test material combustion increased from 64.7 kW/m 2 to 100.7 kW/m 2 . The rate of mass loss of materials accelerates with the increase of thermal radiation intensity; As the intensity of thermal radiation increases, the fire hazard of the material increases., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:Zhi Wang reports financial support was provided by 10.13039/501100001809National Natural Science Foundation of China. Zhi Wang reports a relationship with 10.13039/501100001809National Natural Science Foundation of China that includes: funding grants., (© 2024 The Authors.)

Polymeric foam core sandwich composites are the nascent materials used in marine and aerospace structural applications for its low-density characteristics. A special class of foam called syntactic foam is one of the promising core material having high specific properties. However, these polymeric foam core sandwich composite structures may encounter problems in correlation with temperature and fire. Damages that happen due to the variation in temperature and by the catch of fire are sometimes imperceptible which may lead to the deterioration of load carrying ability or catastrophic failure of these composite structures. Present investigation is focused on the possibilities of reducing the extent of damages due to variation in temperature and by the catch of fire by enhancing its thermal stability and flame resistance characteristics. This was achieved from the development of syntactic foam by embedding hollow micro-spherical particles in phenolic resin for fire containment or fire isolation. Result of the experimentation reveals that the phenolic syntactic foam core was thermally more stable than glass/epoxy face skins up to a temperature of 450°C. The minimum concentration of oxygen required for burning was found to be 30%, in which phenolic syntactic foam core helps in flame isolation, whereas E-glass/epoxy face skins contribute to flame spread in the event of burning of sandwich composites. Improved thermal stability and fire resistance characteristics of developed sandwich composites are attributed to the phenolic syntactic foam core and by its orientation. [ABSTRACT FROM AUTHOR]

The development of high strength, fire proof fiber-reinforced polymer matrix composites is significant for automobile industries over the past few decades. This research investigates Ammonium Polyphosphate (APP) influence on thermal and fire performance of the E-Glass/Phenolic hybrid composites fabricated via book press compression molding. Various composition of hybrid laminates with 2, 4, 6, 8, 10 weight percentages of APP fabricated along with neat laminates and its thermal, fire performances like limiting oxygen index (LOI), UL 94, Influence of accelerated heat aging on impact behavior of hybrid samples were studied and reported along with the morphology studies. Results showed that higher APP filled specimens possess better fire performance than neat samples. UL 94 vertical and horizontal burning tests reports that 8 and 10 wt. % APP filled specimens showed a lower flame spreading rate and meets V-0 criteria. Similarly, heat aging significantly limits the hybrid configurations energy absorption capacity depending on increasing temperature and time duration. The investigations concluded that the proposed E-Glass/Phenolic/Ammonium Polyphosphate hybrid composites were apt for developing sustainable E-Vehicle battery casings and fireproof automobile components. [ABSTRACT FROM AUTHOR]

The research content is to develop nanocomposite coatings to provide fire resistance to structural steel substrate.This study presents the results of the different formulations developed to study the effects of nanoclay on coating expansion and thermal shielding during the fire test. The anti-fire effect of nanocomposite coating is improved by 5 wt.% dispersed nanoclay particles. The coatings are characterized by using scanningelectron microscope (SEM), Flame-retardant evaluation methods: LOI, UL 94 rating. Effect of additional content of nanoclay on combustion efficiency is studied by flame retardant test and measurement of limited oxygen index and effective thermal conductivity. [ABSTRACT FROM AUTHOR]

Copyright of Cotton Textile Technology is the property of Cotton Textile Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A series of new poly(amide-imide)s was prepared by polycondensation of our already reported diamine, N,N'-[((propane-2,2-diylbis(4,1-phenylene) bis(oxy))bis(4,1-phenylene)]bis(4-aminobenzamide) (BDM) containing flexible ether and amide linkages with different aromatic dianhydrides via simple two-step method. The synthesized poly(amide-imide)s were characterized by FTIR spectroscopy and elemental analysis. These poly(amide-imide)s demonstrated nice solubility in most of the organic solvents at ambient temperature and upon heating. They also revealed great thermal stability and showed glass transition temperatures (Tgs) exceeding 150 °C in addition to the temperature of 10% weight loss (T10) that fluctuated from 460 to 522 °C having more than 59% residual yield at 800 °C in nitrogen atmosphere indicating their flame retardant characteristics. Furthermore, they also showed interesting photoluminescent properties with blue green solution emission properties, redox activity, and lower onset oxidation potentials with appreciably shallow HOMO levels. [ABSTRACT FROM AUTHOR]

A novel phosphorous- and nitrogen-containing flame retardant, ditrimethylolpropane biphosphoramide diethyleneamine (DBD), was synthesized. Its chemical structure is characterized by Fourier-transform infrared spectroscopy and 1H nuclear magnetic resonance spectroscopy. The effect of DBD on the physical, mechanical, and antistatic properties, thermal stability, and flame retardancy of wool fabric was systematically investigated. Thermogravimetric analysis showed that the initial decomposition temperature of DBD was 165 oC and 243 oC under nitrogen and air atmosphere, respectively. Furthermore, after 30 washes, the treated wool fabric exhibited excellent wash durability and good antistatic properties. Vertical burning tests indicated that both the burning time and char length of the treated wool fabric were lower than those of the flame-retardant standard, leading to a B1 flame retardant rating for the treated wool fabric. Compared to untreated wool fabric, the limiting oxygen index value of treated wool fabric increased significantly from 25.7% to 34.7%. [ABSTRACT FROM AUTHOR]

To prepare flame-retardant epoxy resin, phosphorus compound containing di-hydroxyl group (10-(2,5-dihydroxyphenyl)-9,10-dihydro-9-oxa-10-phospha phenanthrene-10-oxide, DOPO-HQ) was reacted with uncured epoxy resin (diglycidyl ether of bisphenol A, YD-128) and then cured using a curing agent (dicyandiamide, DICY). This study focused on the effect of phosphorus compound/phosphorus content on physical properties and flame retardancy of cured epoxy resin. The thermal decomposition temperature of the cured epoxy resins (samples: P0, P1.5, P2.0, and P2.5, the number represents the wt% of phosphorus) increased with increasing the content of phosphorus compound/phosphorus (0/0, 19.8/1.5, 27.8/2.0, and 36.8/2.5 wt%) based on epoxy resin. The impact strength of the cured epoxy resin increased significantly with increasing phosphorus compound content. As the phosphorus compound/phosphorus content increased from 0/0 to 36.8/2.5 wt%, the glass transition temperature (the peak temperature of loss modulus curve) increased from 135.2°C to 142.0°C. In addition, as the content of phosphorous compound increased, the storage modulus remained almost constant up to higher temperature. The limiting oxygen index value of cured epoxy resin increased from 21.1% to 30.0% with increasing phosphorus compound/phosphorus content from 0/0 to 36.8/2.5 wt%. The UL 94 V test result showed that no rating for phosphorus compounds less than 19.8 wt% and V-1 for 27.8 wt%. However, when the phosphorus compound was 36.8 wt%, the V-0 level indicating complete flame retardancy was obtained. In conclusion, the incorporation of phosphorus compounds into the epoxy chain resulted in improved properties such as impact strength and heat resistance, as well as a significant increase in flame retardancy. [ABSTRACT FROM AUTHOR]

Bisphenol-substituted spirocyclic phosphazene derivatives were synthesized in 85%–94% yields and analyzed for flame retardant application to cotton fabric using Limiting Oxygen Index, Fourier transform infrared thermogravimetric analysis, differential scanning calorimetry, microscale combustion calorimetry, thermogravimetric analysis, and scanning electron microscopy. The thermogravimetric analysis methods indicate a decomposition pathway consistent for phosphorus-nitrogen-containing compounds. Levoglucosan phosphorylation and carbonaceous char formation were observed. Limiting Oxygen Index testing of these compounds on cotton-based fabrics showed improved flame resistance compared to untreated fabrics. [ABSTRACT FROM AUTHOR]

An additive flame retardant was prepared from DOPO-HQ. Fourier transform infrared spectroscopy (FT-IR) was used to analyze its chemical structure. It was added to the experimental formula to prepare EP composite material, and the limiting oxygen index experiment and thermogravimetric analysis experiment were carried out on the material, and the scanning electron microscope experiment was carried out on the residual carbon after combustion. The results show that the modified epoxy resin has a limiting oxygen index of 29.5%, and there is no droplet during combustion; thermogravimetric analysis experiments show that the temperature at which the thermal weight loss is 5%wt decreases, but the residual carbon rate increases. Scanning electron microscopy (SEM) test results show that carbon layer formed by the combustion products of epoxy resin is denser..

In this work, polyamide 66/polyphenylene oxide (PA66/PPO) composites, including the flame retardants 98 wt% aluminum diethylphosphinate + 2 wt% polydimethylsiloxane (P@Si), Al(OH)3-coated red phosphorus (RP*), and glass fiber (GF), were systematically studied, respectively. The limiting oxygen index (LOI), UL-94 vertical burning level, and thermal and mechanical properties of the PA66/PPO composites were characterized. The results showed that the P@Si and RP flame retardants both improved the LOI value and UL-94 vertical burning level of the PA66/PPO composites, and PA66/PPO composites passed to the UL-94 V-0 level when the contents of P@Si and RP* flame retardants were 16 wt% and 8 wt%. On the other hand, the mechanical properties of the PA66/PPO composites were reduced from a ductile to a brittle fracture mode. The addition of GF effectively made up for these defects and improved the mechanical properties of the PA66/PPO composites containing the P@Si and RP*, but it did not change the fracture mode. P@Si and RP* flame retardants improved the thermal decomposition of PA66/PPO/GF composites and reduced the maximum mass loss rates, showing that the PA66/PPO/GF composites containing the P@Si and RP* flame retardants could be used in higher-temperature fields.

The objective of this study is to investigate the use of microwave-soaking combination methods to improve the impregnation efficiency of Ammonium Sulfate (AS) as a fire-retardant into the teak wood. Various methods were compared by testing the (WPG). Experiments were performed for different impregnation conditions such as microwave power, radiation time and soaking time. The results showed the optimum condition for maximum WPG with microwave was to impregnate with AS solution using microwave power of 300 W, with a radiation time of 10 min, and then soaking at 75ºC for 6 hours. The effect on the properties of the treated wood before and after microwave-soaking treatment was also investigated by Fourier Transform Infrared Spectroscopy and compression strength parallel to the grain. Furthermore, this work evaluated the effect of AS contents having a concentration of 0-25 wt.% impregnated into teak on flammability and leachability. Flammability was tested using the Limiting Oxygen Index (LOI) and, leachability was carried out according to JIS K 1571. The test indicated that the LOI values increased from 21.24% for untreated wood to 38.5 for 25 wt.% AS as a self-extinguishable wood, and the leaching of AS from wood was in the range 1-2.5%, indicating the good fixation of AS in teak.

A novel P–N based, flame retardant ammonium salt of pentaethylenehexamine octa (methylene-phosphoric acid) (APHOMPA) was synthesized in this study. The structure of the prepared material flame retardant contains eight reactive ammonium phosphorus groups and was characterized by 1H NMR, 13C NMR, 31P NMR, and (Fourier-transform infrared) FT-IR. The results showed that cotton fabrics finished with this flame retardant exhibited excellent flame retardancy and durability. The cotton fabrics finished with 30% APHOMPA solution had limiting oxygen index value 40.5%, and maintained 28.8% even after 50 laundering cycles. The FT-IR results showed that APHOMPA could be grafted on cellulose through P–O–C covalent bond. Vertical flammability, cone calorimetry, thermogravimetric (TG), and TG-IR results revealed the excellent flame retardancy of the finished cotton fabrics and suggested that the flame retardant mechanism of APHOMPA is a condensed phase process. Scanning electron microscopy results suggested the flame retardant entered the inner space of the cotton fabrics, and the X-ray diffraction results showed slight changes to the cotton crystal structure in the finishing process. The breaking strength, softness, and whiteness of finished cotton fabrics were sufficient, suggesting this retardant can be used to prepare treated cotton for multiple applications. [ABSTRACT FROM AUTHOR]