Synergistic Flame Retardant Effect Research Articles

A functional phosphorus/nitrogen‐containing compound for endowing epoxy resin simultaneously with better fire safety, comparable transparency and improved toughness

AbstractCurrently, the flame retardancy of epoxy resin (EP) was achieved at the expenses of the transparency and/or toughness. In the present work, a phosphorus/nitrogen‐containing compound (FDNP) was synthesized by one‐pot method using 9,10‐dihydro‐9‐oxa‐10‐phospha‐phenanthrene‐10‐oxide, furfural and N‐phenyl‐p‐phenylenediamine as raw materials, and further adopted as a functional agent for epoxy resin. The results demonstrated that the FDNP remarkably improved the fire safety of EP. The incorporation of 4 wt% FDNP enabled EP to pass UL‐94 V‐0 rating test and achieve a limiting oxygen index value of 35.5%; meanwhile, the peak heat release rate, total heat release rate and total smoke release were significantly reduced by 41.3%, 41.6% and 72.5% as compared with the pure EP, respectively. What is more, the EP/4 wt% FDNP composite kept almost the same transparency of the pure EP, simultaneously its impact strength was more than doubled as that of the pure EP. Herein, the improved flame retardancy is contributed to a synergistic biphasic flame retardant effect including the formation of a compact protective carbon layer and the release of both non‐combustible gases and phosphorus‐containing radicals.

Characterization and Flame-Retardant Properties of Cobalt-Coordinated Cyclic Phosphonitrile in Thermoplastic Polyurethane Composites.

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.

Alloying synergistic flame retardant effect on PA6 by polyimide containing alkyl hypophosphate structure

A novel flame retardant − bismaleimide polyalkyl phosphinate aluminium (BPPA), containing both imide and phosphinate structures, was designed and synthesized to investigate the intramolecular synergistic flame retardant effect between imide and phosphinate structures and alloying effect of the imide structure with PA6. Based on the flame retardant and mechanical properties of BPPA/PA6 composites, the alloying flame retardant effect of BPPA on PA6 was systematically investigated. The PA6 material had almost no char after burning; however, BPPA can produce a large amount of residue and form a dense char layer during combustion of PA6 matrix, effectively reducing the heat release, while BPPA also improved the mechanical properties of PA6 composites through the alloying effect. The peak heat release rate (pk-HRR) decreased by 55.8 %, and the residue yield increased by 9.2 wt% for 20BPPA/PA6, compared with the PA6. After compounding aluminum diethylphosphinate (ADP) and BPPA, the flame retardancy of the composites can be further improved. The LOI value of the 8ADP/6BPPA/PA6 was increased to 29.8 % and passed the test of UL94 V-0 level. Its pk-HRR and residue yield were similar to that of the 14BPPA/PA6, which indicated that the compounding system of ADP and BPPA can provide excellent charring properties and gas-phase flame retardancy of PA6. Meanwhile, the alloying BPPA with PA6 not only reduced the effect on the tensile strength of ADP on PA6, but also improved the breaking elongation of the composite. In conclusion, it provides a new direction for developing high-performance halogen-free flame retardant polyamides.

A zinc-embedded multicomponent copolymer customized for polypropylene and its synergistic flame-retardant effect and outstanding mechanical properties

The poor compatibility between the common polar intumescent flame-retardant system (IFR) and the nonpolar polypropylene (PP), as well as the high additive amount, seriously impacts the mechanical properties of the composites. This study introduced collaborative flame-retardant technology to construct block copolymer flame retardants and prepared a zinc-embedded multicomponent copolymer (PM-Zn2+) customized for PP composites. In the PM-Zn2+ system, zinc oxide was embedded into the copolymer composed of piperazine phosphate oligomer and melamine phosphate. PM-Zn2+ exhibited an amorphous structure with extremely low crystallinity and demonstrated specific morphological adaptability. The PM-Zn2+ were well dispersed in the PP matrix and changed their morphology during processing. When applied to PP, excellent flame retardancy and mechanical properties were obtained by using a minimal amount of flame retardants (20 %). PM-2 %Zn2+ gave PP an LOI value of 31.5 %, and achieved a UL94 V-0 rating (1.6 mm thick), exhibiting a lower heat release rate and smoke release. The flame-retardant mechanisms of PM-Zn2+ mainly involved the synergistic and aggregative effects. Transition metal zinc synergistically interacted with polyphosphate groups to create a charring barrier effect and enhance synergistic smoke suppression, leading to a significant reduction in combustion intensity. In comparison to the Mix-Zn/PP composites, the mechanical properties of PM-Zn2+/PP were significantly enhanced due to the specific morphological adaptability and improved compatibility. The elongation at break increased significantly from 15.6 % to 627.9 %, marking a remarkable improvement of 40-fold improvement, while the impact strength rose from 23.7 kJ/m2 to 54.3 kJ/m2, representing a 129 % enhancement. Finally, the zinc-embedded multicomponent block copolymer offers a promising approach to developing high-performance flame-retardant polypropylene materials.

Double-shell microstructures based on thermochromic materials and biomass flame retardants towards solving the fire and icing hazards

Due to the extreme dynamic weather, important industrial facilities and infrastructure providing vital support for people’s lives usually face the hazards of fire and icing, especially in the weather of thunderstorm and ice. Therefore, to further establish a safe community, we develop a dual-functional polyurea (PUA) coating used as protective materials by introducing flame retardancy and solar de-icing performance. Based on the microencapsulation and electrostatic self-assembly technologies, flame-retardant and thermochromic microcapsules (TCM) are firstly prepared and then added into PUA resin, by using melamine resin and bio-based phytic acid/chitosan (PA/CS) hybrids as double-shell materials. The high phosphorus content of PA and the carbon-forming effect of CS together play a synergistic flame retardant effect, not only improving the thermal stability of microcapsules but also enhancing the flame retardant property of PUA coating. In the cone calorimetry test, the ignition time of TCM@PA/CS@PUA-3 is longer, and the pHRR is reduced by 19.93 %, which shows the improvement of flame retardant performance. Due to the thermochromic mechanism, TCM@PA/CS@PUA composite coatings are able to adjust the photo-thermal conversion ability according to different environment temperature, achieving less temperature in hot environment and higher temperature in cold environment. The excellent photo-thermal conversion ability also promotes the ice melting and slide in 525 s. This polyurea composite coating with both flame retardant and de-icing properties shows great potential for maintaining the normal operation and safety of outdoor industrials and infrastructure in extremely dynamic weather conditions.

Bio-based and fireproof radiative cooling aerogel film: Achieving higher sustainability and safety

Even though significant advantages in the energy-free regulation of temperature are presented, the practical applications of radiative cooling materials in buildings and human surfaces still involve many safety issues, especially for fire hazards of polymer-based materials. Meanwhile, renewable and environmentally friendly materials are urgently needed to develop suitable radiative cooling materials with no adverse environmental impact. Herein, a chitosan-derived composite aerogel film with high solar reflection provided by the addition of melamine-phytic acid (MA/PA) hybrids is designed and prepared, presenting radiative cooling and fireproof performances. The instinct deep-yellow color of chitosan (CS) is successfully shielded by high-reflective MA/PA hybrids, while IR emissivity of up to 90.4 % and solar reflectivity of ∼ 89.3 % are achieved. In outdoor environments, this composite aerogel shows sub-ambient temperature drops of ∼ 4.3 °C and ∼ 3.1 °C in cloudless and cloudy weather, presenting a robust cooling effect. In addition, CS-MA/PA composite aerogel film with 3 mm thickness can isolate the fire of ∼ 500 °C, showing superior fire safety attributed to the synergistic flame retardant effects among chitosan, phytic acid, and melamine, which suppress the initial growth of fire and promote the rapid formation of protective char layer. This work provides a bio-based, fire-safe, and radiative cooling material to decrease the energy consumption of temperature regulation with a more environmentally friendly and safer approach, further promoting the practical application of radiative cooling materials.

Preparation and properties of multilayer core-shell structure ammonium polyphosphate synergistic with THEIC for flame retardant LDPE

In this paper, a new type of highly efficient intumescent flame-retardant low-density polyethylene composite was prepared using two key technologies, namely, microencapsulation encapsulation technology and novel carbon formation technology. Precisely, β-cyclodextrin encapsulated modified ammonium polyphosphate@melamine formaldehyde resin (β-CDMCAPP@MF) was prepared by using Si-IFR synergistic flame retardant effect combined with the gel-solution method, and then flame retardant low-density polyethylene (LDPE) was prepared by compounding with tris-(2-hydroxyethyl) isocyanate (THEIC). The results showed that β-CDMCAPP@MF was modified with MF, β-CD, and silica coating. This modification resulted in excellent hydrophobicity and good compatibility with LDPE. The addition of IFR containing β-CDMCAPP@MF significantly improved the flame retardancy of the LDPE composites. Specifically, when 30 wt% of β-CDMCAPP@MF was added, the ultimate oxygen index of the composites reached 24.7 %, and V-0 grade and the tensile strength went 11.41 MPa. Compared with IFR/LDPE with the same proportion of MF@MCAPP and β-CD@MCAPP, the ultimate oxygen indices were increased by 9.72 % and 12.15 %, respectively. The introduction of THEIC into the flame retardant system resulted in a LOI value of 36.5 % and an FRI value of 2.523, which is 32.33 % higher than that of the composites containing 30 wt% of the flame retardant system (without THEIC). Cone calorimetry test results showed that introducing β-CDMCAPP@MF and THEIC significantly improved the smoke emission.

High flame retardant composite phase change materials with triphenyl phosphate for thermal safety system of power battery module

The thermal safety of battery pack has attracted much attention accompany with the growth in electric vehicles (EVs) in recent years. Although various battery thermal management systems (BTMS) are investigated by many research, the thermal runaway propagation (TRP) of battery packs under extremely abused conditions is just at the level of structural design and theoretical model. How to explore an innovative technology to improve the integrated thermal safety including the BTMS and TRP is still a great challenge. In this study, a multifunctional flame-retardant paraffin (PA)/styrene-butadiene-styrene (SBS)/expanded graphite (EG)/methylphenyl silicone resin (MPS)/triphenyl phosphate (TPP) composite phase change material (PSEMT) has successfully prepared. Besides, it has applied in 26650 ternary power battery modules. When the proportion of MPS and TPP is 1:2, the experimental results reveal that PSEMT possesses high thermal stability, and excellent flame-retardant properties owing to synergistic flame-retardant effect with phosphorus and silicon. Further, the cylindrical 26650 battery module with PSEMT exhibits optimum thermal management performance. Even at 2C discharge rate after ten cycles, the maximum operating temperature of battery module can still be maintained below 50 °C, and the maximum temperature difference is controlled within 4.6 °C. Additionally, it displays an excellent thermal runaway suppression through triggering by multiple heat sources. What's more, the battery with PSEMT can suppress the peak temperature and delay the occurrence time of thermal runaway. Therefore, it can be induced that the battery module with PSEMT can effectively avoid heat accumulation and significantly reduce its thermal safety risk. This study offers a new solution with promising prospects from the perspectives of energy storage and EVs, for balancing the temperature inconsistencies in batteries and suppressing thermal runaway in the battery packs.

Preparation of expandable flake-graphites with different particle sizes and their flame-retardant application for polypropylene

Bisulfate intercalated graphites with different particle sizes were prepared by a chemically oxidative method using natural flaky graphites as raw materials. The morphology and structure of the expandable graphites were confirmed by Fourier transform infrared spectroscopy, X-ray diffraction patterns, and scanning electron microscope. The effect of the particle size on the expanded volume was also investigated. Expandable graphite with +100 mesh particle size (EG100) showed the highest expanded volume of 225 mL/g. Moreover, a combination of expandable graphite, red phosphorus (RP), and melamine cyanurate (MC) into a polypropylene (PP) matrix exhibited a synergistic flame retardant effect. The composite loading EG100, RP, and MC with a mass ratio of 1:1:1 and a total filler content of 18 wt.% achieved a UL94 V-0 rating and a limiting oxygen index (LOI) of 28.9 %. The effect of particle size of expandable graphite on the mechanical properties was also evaluated.

Synthesis of PMM and Synergistic Flame Retardant Effect with Ammonium polyphosphate

A novel flame retardant poly {[(2-Methyl-acrylic acid 2-(dimethoxyphosphoryloxy)-ethyl ester]-co-[2-Methyl-acrylic acid 2-(trimethoxysiloxy)-ethyl ester]} (PMM) containing dimethoxyphosphoryloxy and trimethoxysiloxy groups in side chains was synthesized. The structure of PMM was characterized by Fourier transform infrared spectroscopy (FTIR), nuclear magnetic resonance (1H NMR), and the thermal performance of PMM was characterized by thermal gravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of PMM on polypropylene’s flame retardancy and thermal behaviors was investigated by limited oxygen index (LOI), vertical burning test (UL-94), and TG tests. The experimental results indicate that the addition of PMM helps to improve the flame retardancy and thermal stability of PP. When the addition of PMM and APP in PC was 15% and 20%, the LOI value of PC reached 28.4%, and the UL-94 test rating reached V-0 level. The charred structure observed by scanning electron microscopy (SEM) indicated that the char surface for PP/APP/PMM system holds an intumescent char structure compared to neat PP, and the synergy exists in the composites. The PMM slightly decreased the tensile property in terms of strength but increased the elongation at break for PP composites.

Flame retardant, mechanical, and hot air aging properties of ethylene‐propylene‐diene monomer/ammonium polyphosphate/nano‐silic composite rubber

AbstractIn this work, effect of the ratio of nonhalogenated flame retardants (ammonium polyphosphate [APP] and nano‐silica [nano‐SiO2]) on the mechanical, thermal, and flame retardant properties of ethylene‐propylene‐diene monomer (EPDM) composite rubber were investigated. Vulcanization characteristics, high temperature compression permanent deformation, thermal oxygen aging, dynamic thermodynamic analysis, thermal stability, cone calorimetry, limiting oxygen index (LOI), horizontal vertical combustion (UL‐94), and scanning electron microscopy were carried out. The experimental results showed that the mechanical properties of the composite rubber decreased with the addition of APP. However, the addition of nano‐SiO2 was found to significantly improve the mechanical properties of the composite rubber when it was incorporated. In terms of flame retardant properties of EPDM composite rubber, the combination of APP and nano‐SiO2 has a synergistic flame retardant effect in comparison to the use of single APP flame retardant. The heat release rate of EPDM composite rubber decreased by 34%, the total heat release decreased by 19%, the LOI increased by 76%, and the flame retardant grade of EPDM composite rubber reached V‐0. The EPDM composite rubber fabricated in the present study showed excellent fire resistance and desirable mechanical properties, which are of practical significance for further expanding the application ranges of EPDM rubbers.

Lightweight, flame retardant Janus carboxymethyl cellulose aerogel with fire-warning properties for smart sensor

Lightweight, flame retardant biomass aerogels combining with multi-functionalities are promising for thermal insulation, noise absorption and smart sensors. However, high flammability hinders the application of these aerogels in extreme condition. Herein, lightweight, flame retardant aerogel with fire-warning properties fabricated from resource-abundant graphite and green carboxymethyl cellulose (CMC) is reported. During sonicating expandable graphite (EG) in CMC solution, CMC not only fabricates the downsizing process via hydrogen bonding effect but also forms stable dispersions. Then biomass aerogel is fabricated by freeze-drying strategy and enhanced by metal ionic cross-linking method. This aerogel demonstrates Janus properties for electrical conductivity and thermal conductivity. Due to the synergistic flame retardant effect of graphite nanocomposite and metal ions with a barrier effect and catalytic carbonization capacity, the flame retardancy of these aerogels are enhanced with fire-warning properties. Furthermore, these aerogels are used for monitoring physical deformations as smart sensors, which provides inspiration and a sustainable solution for developing low-cost biomass aerogel with multifunction.

Preparation and performance of intumescent water-based coatings with both thermal insulation and flame retardant functions

Functional flame retardant polymer materials are of great strategic relevance in reducing energy consumption in the wake of accelerated advances in materials science. In this paper, boehmite sol was employed to modify the surface of hollow glass microspheres (HGMs), self-designed a new type of intumescent flame retardant with melamine polyphosphate and starch (M-S system), which subsequently achieved synergistic flame retardant effects and produced high-performance water-based HGMs@Al2O3/M-S composite coatings that could be successively manufactured. As revealed from findings, HGMs@Al2O3 retained the fundamental structure and characteristics of HGMs and enhanced the interfacial compatibility with the water-based polymer matrix. The thermal conductivity of 0.097 W/(m·K) was achieved at 7 wt% HGMs@Al2O3, which notably strengthened the fire resistance of the coating when compounded with 20 wt% M-S. HGMs@Al2O3 also acted as a catalyst for carbon formation and achieves self-extinguishing off fire when the LOI value reached 36 % and UL94 passed the V-0 test. The maximum pyrolysis temperature of the HGMs@Al2O3/M-S composite coatings was 410.1 °C. The results of conical calorimetry indicate that the HRR were reduced by 76.9 % and the THR by 83.8 %, the superior smoke suppression performance of the material. FPI and FGI were 0.21 m2s/kW and 3.02 kW/m2/s separately, indicating a significant improvement in the fire performance of the material, with high residual carbon strength. When burned, HGMs@Al2O3 migrates to the surface of the material and acts as a flame retardant. It demonstrates that the material is superior to previous resemble products and has tremendous potential for application and further industrialization.

Phosphorus-containing reactive compounds to prepare fire-resistant vinyl resin for composites: Effects of flame retardant structures on properties and mechanisms

The traditional flame-retardant method for carbon fiber reinforced vinyl ester resin composites is to add a large amount of solid flame retardants, which not only leads to the deterioration of the material's mechanical properties, but also increases the resin viscosity and affects the molding process of composites. In addressing this issue, this work adopts a liquid reactive flame retardant strategy and synthesizes six novel liquid phosphorus-containing reactive compounds as flame retardants. A comparative study is conducted on the effects of the structure of compounds (valence and group of phosphorus and number of reaction groups) on the properties of materials. The results demonstrate significantly improved flame retardancy and toughness, as well as unaffected viscosity and strength of the resin. When the phosphorus content does not exceed 3 wt%, the limiting oxygen index (LOI) of the resin can reach over 30% and UL-94 passes the V-0 rating. The structure of compounds significantly affects their flame retardancy mechanism. Especially, compounds rich in P-O-C structure have more outstanding condensed phase flame retardancy (promoting charring) and are more favorable for improving the LOI; Compounds rich in P-Ph and P-C structures have higher thermal stability and mainly exert gas phase flame retardancy, which is more beneficial for improving the self-extinguishing properties of materials. Furthermore, a synergistic flame retardant effect is observed between carbon fiber and compounds rich in P-Ph.

Microporous Polyurethane Elastomer’s Comprehensive Properties Affected by Flame Retardant EG/APP

The mechanical characteristics, creep resistance, fatigue resistance, and other comprehensive properties of flame retardants/microporous polyurethane elastomers (FRs/MPUE) have not been systematically researched. Because of this, we used expandable graphite (EG) and ammonium polyphosphate (APP) to conduct this study on FRs/MPUE composites. The thermal degradation and flame retardant characteristics, tensile strength, compressive creep, and dynamic and static stiffness ratio of FRs/MPUE were studied. The findings demonstrated that the optimum synergistic flame retardant effect occurred when the ratio of EG to APP was 2:1. The LOI of MPUE reached 30.5%. The vertical combustion grade achieved V-0. The stage of thermal decomposition was the most stable. However, compared with pure MPUE, the tensile strength was slightly decreased, and the compressive creep and dynamic and static stiffness ratio were slightly increased. The MPUE’s LOI value was more than or equal to 26% when the EG to APP ratio was 2:1 to 1:2. The tensile strength was basically the same as that of pure MPUE. The compression creep was less than 5%, which met the B1 flame retardant requirements and creep resistance performance indicators of floating floor vibration-damping pads.

Synthesis of P-N-S elemental flame-retardant waterborne polyurethane and its application in polyamide fabric

A new type of flame-retardant polyether diols containing phosphorus, nitrogen, and sulfur (SPAE) was first synthesized by using phosphoryl chloride, 2-aminobenzothiazole and ethylene glycol. The SPAE as the soft segment was then utilized to prepare a series of flame-retardant waterborne polyurethanes (SPAE-WPU) through emulsion polymerization. Subsequently, SFR-WPU as a finishing agent was coated on polyamide fabric. When the content of SPAE-WPU was 18 wt%, the coated fabric exhibited a limiting oxygen index (LOI) of 28.2 %, afterflame time of 4.6 s, afterglow time of 0 s and damaged length of 11.2 cm, respectively. After 10 washes, the coated fabric retained its good flame-retardancy and anti-dripping properties. Furthermore, the flame-retardant mechanism of SPAE-WPU was investigated using various spectral analyses, which revealed that the P, N and S elements worked together to create non-combustible gas compounds, release free radicals, and promote dehydration and carbonization, leading to synergistic flame-retardant effects in both gas- and condensed-phase.

The synergistic flame retardant effect of biobased phytic acid arginine salt and hydroxylated montmorillonite in polybutylenes succinate

In this research, hydroxylated nano montmorillonite (DK2) was used as a synergistic agent in combination with phytic acid arginine salt (PaArg). The flame retardancy and mechanical properties of PBS with different amounts of PaArg and DK2 were studied. Furthermore, the synergistic effect and mechanism of PaArg and DK2 in PBS were explored. The results showed that adding 23.5 % PaArg and 1.5 % DK2 increased the limiting oxygen index value (LOI) of the composite to 31.4 %, passing the UL 94 V-0 rating. By adding 25 % PaArg alone, the LOI value of the composite is 26.2 %, and the vertical burning test result is only V-2 rating. The cone calorimetry test results show that the peak heat release rate, total heat release rate, and total smoke production of PBS/23.5 % PaArg/1.5 % DK2 composite are 55.8 %, 17.1 %, and 44.7 % lower than those of PBS/25 % PaArg composite, respectively. All the results showed that PaArg and DK2 exhibited good synergistic flame retardancy in PBS. In addition, the impact strength and bending strength test results show that the impact strength and bending strength of PBS/23.5 %PaArg/1.5 %DK2 composite are higher than those of PBS/25%PaArg composite. This work improved the flame retardant efficiency of biobased flame retardants in PBS.

Synthesis and application of silicone modified flame retardant for polyester fabric

The flame-retardant treatment of polyester fabrics has been widely reported, but most of these treatments cause a significant decrease in the fabric’s handle, such as fluffiness and softness. This study designed and synthesised a new phosphorus-nitrogen-containing silicone oil (PNSO). Then, PNSO as a flame-retardant was treated on polyester fabric through a pad-dry-cure procedure. The limiting oxygen index (LOI), afterflame time and damaged length of the finished polyester fabric (PNSO-F) were enhanced from 20.5%, 73.1 s and 26.8 cm to 28.3%, 4.5 s and 12.3 cm, respectively. After 12 washes, PNSO-F retained its good flame-retardancy and anti-dripping properties. Furthermore, the flame-retardant mechanism of PNSO on fabric was investigated using different spectral methods, which revealed that nitrogen acting in the gas phase, and phosphorus and silicone in the condensed phase worked together to produce a synergistic flame-retardant effect. In addition, KES tests indicated that the fluffiness and softness of PNSO-F were significantly improved.

A ternary polymer flame retardant and its synergistic flame retardant effect with piperazine pyrophosphate in EP

A ternary polymer flame retardant and its synergistic flame retardant effect with piperazine pyrophosphate in EP

Zinc Hydroxystannate/Carbon Nanotube Hybrids as Flame Retardant and Smoke Suppressant for Epoxy Resins.

Novel hybrid flame retardants containing zinc hydroxystannate and carbon nanotubes (ZHS-CNTs) were synthesized using the coprecipitation method, and the structure and morphology of ZHS-CNTs were investigate using an X-ray powder diffractometer (XRD), scanning electron microscope (SEM), transmission electron microscopy (TEM) and thermogravimetric analyzer (TGA). Then, the ZHS, CNTs and ZHS-CNTs were incorporated into EP, respectively, and the flame-retardant and smoke inhibition performance of the composites were compared and studied. Among the three composites, the EP/ZHS-CNT composites have the highest improvements on the fire resistance and smoke inhibition properties. With only 2.0 wt.% ZHS-CNT hybrids, the pHRR of EP/ZHS-CNT composite materials is reduced by 34.2% compared with EP. Moreover, the release of toxic gases including CO, CO2 and SPR from the composites was also effectively inhibited. The mechanisms of flame retardant and smoke inhibition were investigated and the improved properties were generally ascribed to the synergistic flame-retardant effects between ZHS and CNTs, the catalyzing effect of ZHS and the stable network structure of CNTs.