Peak CO Production Research Articles

Constructing a multifunctional reactive MXene-based additive for micro-crosslinking polyurea elastomer to achieve superior mechanical properties and enhanced fire safety

The widespread application of polyurea (PUA) in protective coatings typically requires excellent flame retardancy due to real-world usage scenarios. However, the addition of flame retardant additives often compromises the material’s mechanical properties. In this study, a multifunctional reactive additive, MX-SP-NH2, was creatively prepared by covalently grafting spirocyclic pentaerythritol bisphosphorate disphosphoryl chloride (SPDPC) onto MXene (Ti3C2Tx) surfaces, followed by the introduction of 1,3-propanediamine (PDA) by the reaction with SPDPC. MX-SP-NH2 was then incorporated into PUA, participating in its crosslinking process and significantly enhancing both its mechanical strength and flame retardancy. Compared to the control PUA sample, the micro-crosslinked PUA sample with just 1.0 wt% MX-SP-NH2 demonstrated a 184.3% increase in tensile strength, a 126.1% increase in elongation at break, and a 436.3% increase in toughness. The flammability characterization revealed that the peak heat release rate, peak smoke production rate, and peak CO production rate were reduced by 31.7%, 28.9%, and 61.5%, respectively, indicating a substantial improvement in fire safety. Additionally, the flame retardant PUA-based flexible strain sensors demonstrated stable electrical signal responsiveness. This work has opened up new potential applications of PUA in flexible electronics.

Excellent flame retardant and tough epoxy thermosets with imidazolium tributyl phosphate ionic liquid

The brittleness and flammability of epoxy thermosets (EP) have largely limited their applications. In this work a phosphorus-containing ionic liquid 1-methylimidazolium tributyl phosphate ([Mim]TBP) is designed and synthesized to develop high-performance and flame-retardant epoxy thermosets. [Mim]TBP significantly accelerates the curing and improves the toughness of epoxy thermosets. The tensile toughness, tensile strength, impact strength and flexural strength of samples with 10phr [Mim]TBP increase by 419.7 %, 100.2 %, 71.7 % and 58.3 %, compared with pure EP, respectively. The increased toughness is due to the significant energy dissipation caused by the ionic bonds breaking between Mim and TBP. When the [Mim]TBP content exceeds 10 phr, the limiting oxygen index (LOI) can reach over 30 % and UL-94 test pass the V-0 rating. The peak heat release rate (pHRR), total heat release (THR), total smoke release (TSR) and peak CO production (PCOP) values effectively decrease by 31.5 %, 30.6 %, 48.3 % and 6.3 %, respectively, thanks to the gas and condensed phase mechanisms of the [Mim]TBP. A new strategy was provided for the development of toughness and fire safety performance epoxy thermosets for high-performance industrial applications.

Interfacial engineering of 0D–2D hierarchical MXene@PEI@AgNC nanohybrids to achieve flame retardant, mechanical and antibacterial properties of ABS nanocomposites

It is an intractable challenge that the hierarchical MXene-based nanohybrid fillers are intended to modify the inherent flammability and easily breeding bacteria property of ABS polymeric materials, thereby facilitating wide applicability of ABS composites. Here, an interface engineering strategy was proposed, wherein polyethyleneimine (PEI)-modified silver nanocubes (AgNCs) was firmly assembled on MXenes via electrostatic interaction to construct 0D–2D hierarchical MXene-based nanohybrids (MXene@PEI@AgNC). The MXene was protected and the interface compatibility between MXene-based nanohybrid and ABS matrix was enhanced. Results revealed that the unique hierarchical structure of the composite promoted enhanced dispersion of MXene@PEI@AgNC in the ABS matrix. Combustion tests showed that 1.0 wt%MXene@PEI@AgNC provided the ABS with effective fire safety. Moreover, ABS-1.0 wt%MXene@PEI@AgNC exhibited a 31.88 % decrease in peak heat release rate, a 39.60 % decrease in peak smoke release rate, a 41.50 % decrease in peak CO2 production rate, and a 50.04 % reduction in the smoke factor. Meanwhile, 1.0 wt%MXene@PEI@AgNC improved the tensile strength of ABS-1.0 %MXene@PEI@AgNC (+18.1 %) without reducing the elongation at break. They also enhanced the antibacterial properties of ABS-1.0 %MXene@PEI@AgNC. This study proposed a novel and feasible approach to address the interfacial stability of MXene and to construct MXene-based hierarchical nanoblends, thereby facilitating the wide practical applications of polymeric nanomaterials in industry.

Boosted Solar Thermochemical Low-Temperature CO2 Splitting On Pt/CeO2 by Interface Catalysis.

Solar thermochemical CO2 splitting using metal oxides is considered as a promising approach to produce solar fuels since it is capable to tap abundant sunlight directly and store solar energy in the renewable fuel. It remains a grand challenge to achieve highly efficient CO2 splitting at low temperature (<800 °C) due to insufficient activation of metal oxides for CO2. Herein, the introduction of a small amount of Pt was found to be able to greatly increase the performance of CO2 splitting with the highest peak CO production rate of about 65 mL min-1 g-1, CO productivity of about 53 mL g-1, nearly 100 % CO2 conversion and long-term stability for 0.5Pt/CeO2, which exceeded most of the state-of-the-art transition metals-based oxides even at lower temperature (700 °C). This could be attributed to the addition of Pt leading to the formation of an interface (Pt0-Ov-Ce3+) after CH4 reduction, which improved CO2 activation and dissociation due to beneficial breakage of C=O bond by the cooperation of Pt0 and oxygen vacancies in the interface.

Functionalized LDH via intercalation of gluconate anion and surface assembly of ultrafine copper hydroxide for improving mechanical properties and the fire safety of epoxy resin

To impart epoxy resin (EP) with outstanding mechanical properties and fire safety, LDH was systematically functionalized through gluconate anion (GA) intercalation followed by surface assembly of ultrafine Cu(OH)2, resulting in the LDH-GA@Cu(OH)2 hybrid. Comprehensive characterizations confirmed the successful synthesis of the desired product, with a uniform distribution of ultrafine Cu(OH)2 nanoparticles on the GA-intercalated LDH surface. The findings revealed that LDH-GA@Cu(OH)2 improved the mechanical properties of EP due to the increased LDH layer spacing, facilitating EP chain insertion, and the hydrogen bonding between the –OH of GA and the EP matrix. Fire retardancy tests indicated that the EP composite containing 7.5 wt% LDH-GA@Cu(OH)2 achieved a limiting oxygen index (LOI) of 30.1%. Furthermore, compared to pure EP, the composite demonstrated significant reductions in the peak heat release rate (PHRR) and peak CO production rate (PCOP) by 47.4% and 60.5%, respectively, underscoring its superior flame-retardant and toxic smoke suppression capabilities. Mechanistic studies further indicated that ultrafine Cu(OH)2 enhanced char formation through catalytic charring at the interface, which promoted compact and cohesive char layers. Overall, this work proposes a promising functionalization strategy for LDH to endow EP with excellent comprehensive performance.

Fire-resistant and mechanically-robust phosphorus-doped MoS2/epoxy composite as barrier of the thermal runaway propagation of lithium-ion batteries

Thermal runaway propagation (TRP) is an utmost safety issue in battery modules owing to its derivative accidents of fire or explosion. This study develops a novel flame-retardant epoxy resin (EP) board to prevent the battery TRP. The phosphorus doped MoS2 nanowires (PR-MoS2) is designed and incorporated into EP matrix to acquire EP/3.0 PR-MoS2 composite. The composite shows 159.4 % increase in char yield, 56.7 % decrease in peak heat release rate, 56.6 % reduction in peak CO production rate. By using EP/PR-MoS2-3 (EP/3.0 PR-MoS2 composite with thickness of 3 mm) between 103450-pouch cells, TRP can be effectively stopped. Meanwhile, the temperature of surviving battery remains below 100 °C. Of note, the minimum changes in internal crystal structure, chemical composition and electrochemical characteristics are discerned for the surviving battery. This research will offer inspirations for the design of TRP suppression materials, guaranteeing the safety the battery.

Experimental investigation of photo-thermal catalytic reactor for the reverse water gas shift reaction under concentrated irradiation

An upscaled photo-thermal catalytic reactor for the heterogeneously catalysed reverse Water Gas Shift (rWGS) reaction is tested under simulated concentrated irradiation. The reactor is equipped with an aperture of 144 cm2 area covered by a quartz window, where it receives irradiation flux densities of up to 80 kW/m2 corresponding to an irradiation power input of 1 kW thereby directly irradiating a RuO2 based photo-thermal catalyst that is deposited on a porous support. The system was operated under simulated concentrated sunlight for a total of 45.5 h with 35.4 h of chemical operation. A peak CO production rate of 1.6 mol/h was achieved with an average light concentration factor of 80 in the centre of the catalyst layer. This corresponds to a solar-to-chemical efficiency – defined by the ratio of the product of molar CO production rate and reaction enthalpy for the rWGS reaction and the irradiation power input – of 1.69 %. A calculation approach to determine the catalyst surface temperature under irradiation was introduced and utilised for performance analysis leading to the discussion of design modifications and operating strategies towards performance enhancement.

Intrinsically reactive hyperbranched interface governs graphene oxide dispersion and crosslinking in epoxy for enhanced flame retardancy

Enhancing the flame retardancy of epoxy (EP) resins typically entailed a trade-off with other physical properties. Herein, hyperbranched poly(amidoamine) (HPAA) and phytic acid (PA) were used to functionalize graphene oxide (GO) via electrostatic self-assembly in water to prepare a phosphorus-nitrogen functionalized graphene oxide nanosheet (PN-GOs), which could be utilized as high efficient flame-retardant additive of epoxy resin without sacrificing other properties. The PN-GOs demonstrated improved dispersion and compatibility within the EP matrix, which resulted in significant concurrent enhancements in both the mechanical performance and flame-retardant properties of the PN-GOs/EP nanocomposites over virgin EP. Notably, the incorporation of just 1.0 wt% PN-GOs yielded a 20.4, 6.4 and 42.7 % increases in flexural strength, flexural modulus and impact strength for the PN-GOs/EP nanocomposites, respectively. Furthermore, simultaneous reductions were achieved in the peak heat release rate (pHRR) by 60.0 %, total smoke production (TSP) by 43.0 %, peak CO production rate (pCOP) by 57.9 %, and peak CO2 production rate (pCO2P) by 63.9 %. This study presented a facile method for the design of GO-based nano flame retardants, expanding their application potential in polymer-matrix composites.

Construction of sustainable and highly efficient fire-protective nanocoatings based on polydopamine and phosphorylated cellulose for flexible polyurethane foam

Layer-by-layer (LBL) self-assembly is an effective strategy for constructing fire-resistant coatings on flexible polyurethane foam (FPUF), while the efficiency of fire-resistant coatings remains limited. Therefore, this study proposes an in situ flame retardancy modification combined with LBL self-assembly technology to enhance the efficiency of flame retardant coatings for FPUF. Initially, polydopamine (PDA) and polyethyleneimine (PEI) were employed to modify the FPUF skeleton, thereby augmenting the adhesion on the surface of the skeleton network. Then, the self-assembly of MXene and phosphorylated cellulose nanofibers (PCNFs) via the LBL technique on the foam skeleton network formed a novel, sustainable, and efficient flame retardant system. The final fire-protective coatings comprising PDA/PEI and MXenes/PCNF effectively prevented the collapse of the foam structure and suppressed the melt dripping of the FPUF during combustion. The peak heat release rate, the peak CO production rate and peak CO2 production rate were reduced by 68.6 %, 61.1 %, and 68.4 % only by applying a 10-bilayer coating. In addition, the smoke release rate and total smoke production were reduced by 83.3 % and 57.7 %, respectively. This work offers a surface modification approach for constructing highly efficient flame retardant coatings for flammable polymeric materials.

Self-assembly Fe-Co MOF@BN and epoxy resin nano composites with highly enhanced flame retardancy and smoke suppression properties

A shuttle-shaped Fe-Co bimetallic metal organic frameworks (MOFs) on sheet-like hexagonal boron nitride (h-BN) was fabricated via an organic-inorganic hybrid strategy, forming a novel Fe-Co MOF@BN flame retardant, and the hybrids together with ammonium polyphosphate (APP) were incorporated into epoxy resins to explore their flame retardancy and smoke suppression effects. When combining 0.5 % Fe-Co MOF@BN with 9.5 % APP, the peak heat release rate, peak smoke release rate, CO production rate, and peak CO2 production rate of the EP composite (EP/APP/Fe-Co MOF@BN) were reduced by 73.7 %, 71.4 %, 70 %, and 80 % respectively, compared to epoxy. The limiting oxygen index increases to 30.2 %, indicating the EP/APP/Fe-Co MOF@BN composites have superior fire safety performance. The excellent fire performance of EP/APP/Fe-Co MOF@BN composites benefiting from the barrier effect of Fe-Co MOF@BN lamellar structure, the catalytic carbonization of Fe and Co, the gas phase dilution of APP and the enhancement of the cross-linking degree of the char layer. Meanwhile, Fe-Co MOF@BN improves the dispersion of APP in the EP composites, which broadens the application range of MOF and h-BN. Herein, the EP/APP/Fe-CoMOF@BN composites with high flame retardancy, low smoke production rate, and excellent mechanical properties provide a feasible solution for the use of EP under high temperatures.

Advancing flame retardancy, mechanical properties, and hydrophobicity of epoxy resins through bio-based cinnamaldehyde derivative

Developing flame retardants based on biomass materials to improve the flame retardancy and multifunctionality of epoxy resin (EP) is crucial. Herein, we synthesized a novel derivative, PPABCA, combining cinnamaldehyde and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide to serve as flame retardants for EP. Incorporating 5 wt% PPABCA into EP (EP/PPABCA-5) demonstrated remarkable flame retardancy, with a limiting oxygen index of 33.7% and a V-0 rating in UL-94 test. It also reduced the peak heat release rate, total heat release, and peak CO2 production by 32.9%, 29.9%, and 42.8%, respectively. The enhanced flame retardancy was facilitated by the capture of phosphorus-containing free radicals coupled with dilution of combustible gas characterized by the blow-out phenomenon and formation of a dense char layer enriched with triazine and phosphorus. Furthermore, EP/PPABCA-5 exhibited enhanced flexural and tensile strengths by 20.5% and 16.5% compared to EP, attributed to the increased cross-linking density and π-π conjugation from the high rigidity of PPABCA, along with its good compatibility with EP. Additionally, the improved hydrophobic properties of PPABCA, confirmed by electrostatic potential analysis, further enhanced the hydrophobicity of EP composites. Overall, this work underscored a strategic development of multifunctional, bio-based flame retardant, showcasing efficient flame retardancy, enhanced mechanical properties, and boosted hydrophobicity in EP.

Recyclable porous core-shell Mn-Co-O flame retardant for improving flame retardancy and smoke suppression of epoxy resin

The development of metal oxide flame retardants that are easy to synthesize, efficient, and recyclable would be more beneficial to circular economy. In this work, a porous core-shell Mn3CoOx was developed to efficiently reduce heat, smoke as well as hazardous gas during the combustion of epoxy resin (EP). Compared with pure EP, the peak heat release rate (pHRR), total heat release (THR), peak smoke production rate (pSPR), total smoke production (TSP), peak CO production rate (pCOPR), and peak CO2 production rate (pCO2PR) of EP/Mn3CoOx are reduced by 47.5 %, 21.5 %, 34.6 %, 17.6 %, 58.6 %, and 55.4 %, respectively. It has been shown that Mn3CoOx not only catalyzes the formation of high-quality char layer but also effectively catalyzes the conversion of hazardous gas products into CO2. Recovery experiments of Mn3CoOx filler in EP composites show that the recovery of Mn3CoOx can reach 90.0 %. This work provides insights into the design of efficient metal oxide flame retardants and ideas for the development of recycled flame retardants.

Zinc hydroxystannate coated by polyphosphazene to improve the fire safety and suppress the smoke of epoxy resin

A novel flame retardant containing zinc, tin, phosphorus and nitrogen elements is synthesized from 4,4-Diaminodiphenyl ether (ODA), Phosphonitrilic chloride trimer (HCCP), Triethylamine (TEA) and 1,4-Dioxane by polycondensation reaction. Herein, a hollow, encapsulated material (hollow zinc hydroxystannate@polyphosphazene, H-ZHS@PZS) is introduced as a flame retardant into epoxy resin (EP). And the hollow structure can delay the release of decomposition products and the diffusion of heat. Thermogravimetric analysis (TGA) shows that the EP has good thermal stability after adding H-ZHS@PZS, and the material weight loss of 5 % corresponds to a minimum temperature of 328.4 °C, and the residual carbon mass increases by 77.7 % compared to the pure EP. The well-designed H-ZHS@PZS has good flame retardancy. Cone calorimeter tests (CCT) show that introducing 5 % H-ZHS@PZS into the EP reduces the peak of heat release rate, total heat release, total smoke production, and peak CO production rate by 55.4 %, 19.7 %, 22.5 %, and 59.3 %, respectively. Benefiting from a well-formed nanosheet-polymer interfaces, the mechanical performance is improved. It is worth noting that the improved flame retardancy of EP is mainly assigned to the physical blocking of H-ZHS and the structure of PZS promotes the formation of a dense and continuous char in the condensed phase.

Hierarchical MXene@PBA nanohybrids towards high-efficiency flame retardancy and smoke suppression of robust yet tough polymer nanocomposites at ultra-low additions

Developing efficient flame-retardant MXene-based polymeric materials with enhanced mechanical properties has been a huge challenge. Herein, Prussian blue analogues (PBAs) were used to modify the surface of MXene nanosheets via an electrostatic self-assembly method to construct hierarchical MXene-based nanohybrids (MXene@PBA). Then, MXene@PBA was incorporated into the epoxy matrix to fabricate high-performance epoxy nanocomposites (EP-MXene@PBA). The study indicates that hierarchical MXene@PBA exhibits excellent dispersion performance in the epoxy matrix. Notably, MXene@PBA results in high-efficiency flame retardancy and smoke suppression for epoxy nanocomposites at ultra-low additions. What is very surprising is that only 1.0 wt% MXene@PBA can easily enhance the UL-94 rating of EP-1.0%MXene@PBA to V0. Meanwhile, the peak heat release rate (pHRR), total smoke production (TSP), and peak CO production rate (pCO) are remarkably reduced by 36.70%, 34.28%, and 43.48%, compared to those of the pristine epoxy resin, respectively. Furthermore, the 1.0 wt% MXene@PBA nanohybrids can enhance the flexural and impact strengths of EP-1.0%MXene@PBA. This work provides a feasible strategy for the creation of multifunctional MXene derivatives and their polymeric nanocomposites and holds great promise for many industrial applications.

Research on fire retardant lignin phenolic carbon foam with preferable smoke suppression performance

In this work, a lignin phenolic carbon foam (LCF) with preferable smoke suppression performance was fabricated by substitute 10 wt.% and 30 wt.% phenol with modified lignin in the traditional process. The result showed that the LCF600s (LCFs carbonized at 600℃) with different lignin percentages showed better smoke suppression performance than the traditional phenolic carbon foam (CF600). The peak smoke production rate (pSPR) and total smoke release (TSR) of LCF600s decreased by 6.90%∼48.28% and 80.91%∼96.28%, and the peak CO production rate and CO yield decreased by 41.17%∼70.59% and 53.80%∼77.79%, respectively. Besides, LCF1-10-600 and LCF2-30-600 displayed the best smoke suppression performance (0020, 0.0015 m2/s of pSPR and 0.61, 2.76 m2/m2 of TSR, respectively). Since the introduced modified lignin significantly increased the amount of benzene rings in the forms, the degree of graphitization of the resulted carbon foams greatly improved, leading to better smoke suppression performance. Furthermore, the added lignin facilitated the preservation of the carbon layer, resulting in reducing smoke production consequently.

Hierarchical NiO/Al2O3 nanostructure for highly effective smoke and toxic gases suppression of polymer Materials: Experimental and theoretical investigation

There is still a lack of in-depth investigation of the suppression mechanism for polymeric materials. Herein, based on the density functional theory (DFT) study, the flame retardancy, smoke, and toxic gases suppression mechanisms of hierarchical NiO/Al2O3 nanostructures in thermoplastic polyurethane (TPU) are in-depth revealed. The incorporation of NiO/Al2O3-S into TPU leads to a significant reduction in total smoke release by 41.9%, and peak CO production rate by 47.8% (Cone calorimetry test results). Besides, the NiO/Al2O3-S results in a remarkable decrease of 48% in Dsmax during the smoke density test. Most importantly, based on DFT calculations, incorporating catalysts enhances the adsorption energy of CO, O2, and CO2 on the surface of TPU nanocomposites, thereby facilitating CO oxidation reactions. This is conducive to reducing flue gas emissions and toxicity levels. This work introduces DFT into the flame retardancy research of polymer materials, thus providing reliable guidance for designing highly effective smoke suppressants.

A green organic-inorganic PAbz@ZIF hybrid towards efficient flame-retardant and smoke-suppressive epoxy coatings with enhanced mechanical properties

Developing sustainable bio-based flame retardants for flammable polymers has been a research trend. However, applying bio-based flame retardants to confer excellent flame retardancy, smoke suppression, and mechanical properties to polymers remains a formidable challenge. Herein, a green organic-inorganic hybrid (PAbz@ZIF) was readily prepared through a simple neutralization reaction and in-situ generation method and applied to fabricate high-performance flame-retardant epoxy coatings (EP-PAbz@ZIF). It has been shown that PAbz@ZIF hybrids can enhance the curing activity of epoxy coatings in addition to their excellent dispersibility and interfacial compatibility. In addition, the epoxy coating containing 5.0 wt% PAbz@ZIF (EP-5%PAbz@ZIF) exhibits a higher char yield (from 25.1 wt% to 31.5 wt%) in comparison to pristine epoxy resin (EP). More importantly, the PAbz@ZIF-based epoxy coatings show more efficient flame retardancy and smoke suppression compared to pristine EP. For instance, the 5.0 wt% PAbz@ZIF enables EP-5%PAbz@ZIF to obtain a satisfactory UL-94 rating of V0. Meanwhile, the peak heat release rate, total smoke production, peak CO production rate, and peak CO2 production rate of EP-5%PAbz@ZIF are remarkably decreased by 48.6%, 20.5%, 38.6%, and 56.7%, respectively. Furthermore, EP-5%PAbz@ZIF exhibits enhanced heat insulation performance, flexural strength, and impact strength. This work offers a feasible idea for designing green organic-inorganic PAbz@ZIF hybrids and fabricating high-performance flame-retardant epoxy coatings.

A novel bio-based PAbz@PBA maize structure for improving fire protection, toxic gas suppression and mechanical performance of intumescent flame-retardant epoxy coatings

In recent years, developing bio-based intumescent flame-retardant (IFR) epoxy coatings for fire protection of steel has become a research hotspot. However, how to endow bio-based IFR epoxy coatings with excellent fire protection, toxic gas suppression, and mechanical properties simultaneously remains a formidable challenge. Here, a bio-based IFR hybrid with the maize structure (PAbz@PBA) was easily constructed by an organic-inorganic hybrid strategy and employed to prepare high-performance IFR epoxy coatings. It has been shown that PAbz@PBA hybrids enhance the curing activity of epoxy coatings in addition to their good dispersion and interfacial compatibility. Notably, the epoxy coating containing 5.0 wt% PAbz@PBA (EP-5%PAbz@PBA) exhibits more efficient fire protection (peak heat release rate and total heat release are reduced by 48.3 % and 34.0 %, respectively), smoke suppression (total smoke production is decreased by 35.9 %), and toxic gas suppression (peak CO production rate is reduced by 39.6 %) compared to the virgin epoxy coating. Meanwhile, the heat insulation performance of EP-5%PAbz@PBA shows superiority compared to that of the virgin epoxy coating, as reflected by its lowest backside temperature (66.3 °C). Furthermore, compared with the virgin epoxy coating, EP-5%PAbz@PBA exhibits improved flexural and impact strengths. This work offers a viable idea for designing bio-based PAbz@PBA hybrids and preparing IFR epoxy coatings with various excellent properties.

Hydrogen bonding induced polyphosphazene/MXenes 2D/2D structure loaded with MOFs enabling fire-safe epoxy composite

High thermal runway hazard has been the blocking stone on the way of extended usage of epoxy resin (EP). In such context, the method of preparing fire retardant EP composite with inorganic filler has been adapted, and the shining star of transition metal carbides (MXenes, denoted as MX) has evoked the ardent concern. Nevertheless, the inferior flame retardation efficiency, severe agglomeration, surface scarcity of organic groups have collectively appealed to design MX based flame retardant (FR) with high efficiency. Here, the hydrogen bonding induced strategy and in-situ growth method are utilized to gain FR of P-MX@UIO. Under 2.0 wt% loading, the reductions on peak heat release rate and total heat release reach 48.9% and 45.4%. Meanwhile, the decreases in peak smoke production and total smoke production approach 48.6% and 43.6%. Also, the peak CO production rate is impaired by 48.3%. Such strengths both in suppressing heat and toxicants emissions, are vividly validated via comparison with previous works. Ulteriorly, the inhibited releases of NO and HCN are detected. Peculiarly, the storage modulus is promoted by 75.6% after incorporating P-MX@UIO. This work may inspire the judicious design of MX based FR and fire-safe polymer composites.

Flame protection capability of waterborne epoxy coatings enhanced by inorganic-organic phenyl zirconium phosphate anchored boron nitride

Zirconium phenyl phosphate (ZrPP) has good compatibility in polymers due to its simultaneous inorganic-organic structure. Here, ZrPP was anchored on high barrier boron nitride (BN) by an in situ synthesis scheme using polyaniline (PANI) as an intermediate, which is expected to yield a high performance multifunctional composite flame retardant. Among them, the formation of a rational composite structure of ZrPP and BN is conducive to the maximum enhancement of its barrier effect. Moreover, the presence of Zr and phosphoric acid molecules can effectively promote the cyclization of cleaved molecules and carbon formation in the burning stage, which reinforced the quality and strength of residual carbon. The results showed that the back side temperature of BP@ZrPP/EP waterborne coating was stabilized at the lowest value (167.2 °C), accounting for the most excellent thermal insulation effect of its residual carbon. The BP@ZrPP/EP composite coating showed the maximum expansion height (23.8 mm), expansion rate (18.03) and residual carbon (31.8 %), which depends on the synergistic barrier function of ZrPP and BN. Further, BP@ZrPP based EP exhibited the smallest smoke density rating (38.2 %), the largest limiting oxygen index (31.4 %), and achieved a V0 rating for the UL-94 test. Compared with EP, the peak heat release rate (PHRR), total heat release rate (THR), peak smoke production rate (PSPR), total smoke production (TSP), and peak CO production rate (PCOPR) of BP@ZrPP-filled EP were reduced by 32.9 %, 30.7 %, 33.3 %, 31.3 %, and 35.4 %, respectively, proving its excellent flame retardant and smoke inhibition ability.