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Rational construction of high-efficiency and low-cost catalysts is one of the most promising ways to produce hydrogen but remains a huge challenge. Herein, interface engineering and heteroatom doping were used to synthesize V-doped sulfide/phosphide heterostructures on nickel foam (V-Ni

To improve sulfuric acid recovery from sodium sulfate wastewater, a lab-scale bipolar membrane electrodialysis (BMED) process was used for the treatment of simulated sodium sulfate wastewater. In order to increase the concentration of sulfuric acid (H2SO4) generated during the process, a certain concentration of ammonium sulfate solution was added into the feed compartment. To study the influencing factors of sulfuric acid yield, we prepared different concentrations of ammonium sulfate solution, different feed solution volumes, and different membrane configurations in this experiment. As it can be seen from the results, when adding 8% (NH4)2SO4 into 15% Na2SO4 under the experimental conditions where the current density was 50 mA/cm2, the concentration of H2SO4 increased from 0.89 to 1.215 mol/L, and the current efficiency and energy consumption could be up to 60.12% and 2.59 kWh/kg, respectively. Furthermore, with the increase of the volume of the feed compartment, the concentration of H2SO4 also increased. At the same time, the configuration also affects the final concentration of the sulfuric acid, in the BP-A-C-BP (&ldquo, BP&rdquo, means bipolar membrane, &ldquo, A&rdquo, means anion exchange membrane, and &ldquo, C&rdquo, means cation exchange membrane, &ldquo, BP-A-C-BP&rdquo, means that two bipolar membranes, an anion exchange membrane, and a cation exchange membrane are alternately arranged to form a repeating unit of the membrane stack) configuration, a higher H2SO4 concentration was generated and less energy was consumed. The results show that the addition of the double conjugate salt is an effective method to increase the concentration of acid produced in the BMED process.

Background: Two-line hybrid wheat system using thermo-photo sensitive genic male sterility (TPSGMS) is now a dominant and promising approach of wheat heterosis utilization in China. However, during past twenty years only several TPSGMS lines have been capable of practical application in hybrid wheat breeding and production, which reduced the opportunities and efficiency of creating hybrids with strong heterosis. Introducing doubled haploid (DH) breeding could be a helpful strategy to efficiently develop practically usable TPSGMS lines. Results: F 1 s and selected F 2 and F 3 sterile plants from eight crosses made from two commercial TPSGMS lines were used to produce DH lines by using the wheat × maize system. Twenty four elite sterile lines possessing stable sterility, good outcrossing and yield potential, resistance to yellow rust and powdery mildew, and desirable plant height (50-60 cm) were obtained within 4 years through at least one year evaluation. Twenty from twenty four elite lines showed stable sterility in repeated tests of two or three years, will be selected for hybrid breeding. The percentage of elite lines within total tested DH lines produced from filial generations was in the order of F 2 > F 3 > F 1 in this study. Conclusions: Our study shows that DH breeding is more efficient for the selection of traits controlled by recessive gene(s) compared with conventional breeding, especially for the sterility of TPSGMS wheat. Coupling DH techniques with conventional breeding would be an efficient strategy for developing practically usable wheat TPSGMS lines in respect to number and saving time, which is helpful for further improving the efficiency of wheat hybrid breeding. Producing DHs from F 2 generation appeared to be the better choice considering the balance of shortening breeding time and overall breeding efficiency.

The gas sensing technique based on the differential pressure principle is quite suitable to evaluate the effectiveness of gas fire extinguishing system. This paper is focused on the study of the change rule of its response fluctuation that is critical to the concentration measuring accuracy. The variation of response fluctuation and sensing performance with sensing structure and constant temperature was explored. Results show that it will often enlarge the response fluctuation when promoting the response/sensitivity or response rate by changing the sensing structure, which can cover the improvement in sensitivity causing the decrease in measuring precision, especially for high concentration. However, the increase of temperature will reduce the response fluctuation while improving the response/sensitivity and response rate, which is a good way to promote sensing performance. The research in the paper can provide suggestions for the optimization design of the sensor.

In this article, carbon microspheres (CMSs) synthesized by the hydrothermal method and CMSs-Fe (with Fe3+ adsorbed on the surface of CMSs) were combined with ammonium polyphosphate (APP) to achieve the fire safety improvement of thermoplastic polyurethane (TPU). The fire safety performance of TPU composites was investigated by the cone calorimeter test, microscale combustion calorimeter test, thermogravimetric analysis/infrared spectrometry, Raman spectrometry, X-ray photoelectron spectroscopy, and scanning electron microscopy. The results showed that CMSs and CMSs-Fe can improve the fire safety performance of TPU/APP composites and the effect of CMSs-Fe was better than that of CMSs. The peak heat release rate of the sample containing 0.25 wt % CMSs and 7.75 wt % APP was 16.7% lower than that of the sample containing 8.00 wt % APP, and the content of toxic gases was also reduced in the fire smoke. Also, total heat release and total smoke release of the sample containing CMSs-Fe were 54.7% and 11.6%, respectively, lower than those of the sample containing 0.25% CMSs. It confirmed the contribution of CMSs to the flame retardant system, and the performance of CMSs is improved by adsorbing Fe3+.

Efficient flame-retardant TPU/TiO2 nanocomposites were synthesized by molten blending method. The morphological and structural analysis indicated that TiO2 nanoparticles could be well dispersed in TPU and increased compatibility with the polymer. The obtained mechanical and thermal data suggested that intense cross-linking interaction between TiO2 and TPU promoted more stable network structure, which increased tensile length at break, storage modulus and loss modulus and thermal stability. Furthermore, the cone results demonstrated that TiO2 could not only decrease HRR, but also provide more stable char due to its high heat resistance, and catching and isolating oxygen molecules. Though ignition was inevitably earlier and peak value appearance caused transient thermal conductivity, TiO2 could greatly deplete combustible smoke particulates on the surface of TPU by accelerating degradation of combustible gases to prevent further penetration and destruction from TPU surface as oxygen insulation barrier. Therefore, TiO2 as a kind of effective flame-retardant and smoke suppression material can be applied in the flame retardancy of TPU.

Graphitic carbon nitride/polyaniline doped with phosphoric acid (g-C3N4/PANI@PA) hybrids was prepared by polymerising aniline monomer on the surface of g-C3N4 nanosheets, which used an in-situ chemical oxidative polymerisation method. Intumescent fire retardant (IFR) epoxy coatings with g-C3N4/PANI@PA were prepared, and fire resistance and waterproofing performance of coatings were investigated. The energy dispersive X-ray spectrometry image showed phosphorus element dispersing evenly on the fracture surface of epoxy composite with 0.25 wt% g-C3N4/PANI@PA (EP-0.25CP@PA), which indicated that g-C3N4/PANI@PA dispersed in coating evenly. The results of the cone calorimeter test (CCT) showed that the values of peak heat release rate (pHRR), total smoke release (TSR), total carbon monoxide production (TCOP) of pure epoxy resin (EP-0) were 1389.0 kW/m2, 22.6 m2 and 3.6 g, respectively. In addition, the related data of intumescent fire retardant coating (EP-IFR) were 374.8 kW/m2, 12.9 m2, and 2.1 g, respectively. When 0.25 wt% g-C3N4/PANI@PA was introduced into EP-IFR to get EP-IFR-0.25CP@PA sample, the pHRR, TSR, and TCOP values were reduced to 347.3 kW/m2, 7.9 m2, 1.5 g, which were reduced by 75.0%, 65.0%, and 60.0% compared with EP-0, respectively. Furthermore, g-C3N4/PANI@PA could also improve the hydrophobicity of IFR epoxy coatings. The water contact angle increased from 50.0° (EP-IFR) to 84.8° (EP-IFR-0.25CP@PA). It was confirmed that g-C3N4/PANI@PA could improve the fire protection, smoke suppression performance, and waterproof performance of IFR epoxy coating. All of those provide a certain theoretical support for applying g-C3N4/PANI@PA in intumescent fire retardant coatings.

The coordination driven self-assembled materials are in high demand of advanced energy chemistry, which remain largely unexplored. Here an ultra-simple and environmental friendly strategy for fabricating metal-organic gels (MOGs) in terms of electrochemical overall water splitting was reported. Through electrochemical testing, the Ni0.6Fe0.4-MOG achieves the lowest oxygen evolution reaction (OER) overpotential of 285 mV (j10), 347 mV (j100), 445 mV (j500) (GC electrode) and 173 mV (j10, NF electrode) in 1 M KOH, an ultra-low Tafel slope of 33 mV dec−1 and long-term stability, outperforming most of the reported polymer catalysts. On account of the moderate hydrogen evolution reaction (HER) performance (159 mV (j10)), thereby can drive the two-electrode electrolyzer at a relatively low cell voltage of 1.61 V (1.48 V when using Pt/C as cathode) and no significant attenuation after 20 h. Our work has demonstrated that the MOGs could break the shackles of current polymer catalysts for electrocatalysis.

There are still great challenges to prepare high-efficiency Ru-based catalysts that are superior to Pt/C under acidic conditions, especially under high current conditions. In this work, a series of surfactant-free noble metal doped Ru/CNT (M-Ru/CNT, M = Pt, Rh, Pd, Ir, CNT stands for carbon nanotube) are prepared by microwave reduction method in 1 minute with ≈3-3.5 nm in size for the first time. In 0.5 m H2 SO4 , the overpotential of Pt-Ru/CNT (Pt: 4.94 at %) is only 12 mV. What's more, it also has much larger electrochemical surface area and intrinsic activity than Pt/C. Pt-Ru/CNT still has an ultra-small overpotential under high current density (113 mV at 500 mA cm-2 , 155 mV at 1000 mA cm-2 ). At the same time, it possesses excellent stability regardless of high current or low current after the durability test of 100 h. Theoretical calculation also deeply reveals that Ru is the main adsorption site of H+ . The comparison of the electronic structure of a series of noble metals adjusted by Ru shows that Pt has the most excellent Gibbs free energy of the adsorbed hydrogen and promotes the desorption of the product.

Lithium–Oxygen (Li–O2) batteries have great potential for promising next generation battery, owing to their high theoretical energy density. However, this system still faces many problems such as poor cycling performance and low coulombic efficiency, which mainly stems from the parasitic side reactions on cathode, the decomposition of electrolyte and the corrosion of Li anode. Herein, a novel gel polymer electrolyte (GPE) containing the polymethyl methacrylate (PMMA) with high stability towards the superoxide molecules and ionic liquid (IL) with the non-volatility (PMMA/IL-GPE) is designed by ultra violet (UV) treatment. PMMA/IL-GPE not only possesses the excellent ion conductivity (0.92 mS cm−1), the wide voltage window (not be oxidized until > 4.7 V) and superior leakproof property, but also effectively protects Li anode from O2-attacking. Moreover, we have further applied electroplating strategy to synthesize the binder-free Ru-coating N, P co-doped cathode (Ru@NPC), which greatly reduce the side reaction of cathode and reduce the charging overpotential. Hence, the Ru@NPC based Li–O2 batteries using PMMA/IL-GPE show effectively improved discharge capacity (32793.5 mAh g−1). When operated at the limited capacity, this battery can run for over 120 cycles with the low charge overpotential of

Rechargeable Li–CO2 batteries have attracted extensive attentions since their excellent abilities of absorbing CO2 and delivering super-high energy density. Recently, many effective catalysts have been developed to improve the performance of Li–CO2 batteries, which nevertheless is still inhibited by problems derived from Li anodes and liquid electrolyte, such as Li dendrites and electrolyte leakage. In this work, we construct Li-ethylenediamine (LE) layer on Li (LE-Li) and use it to further react with tetraglyme in battery to obtain tetraglyme-based polymer electrolyte (TPE). The uniform LE layer coupled with in-situ formed TPE can not only restrain dendrite generation, Li-induced side reaction and corresponding passivation/pulverization, but also reduce interfacial impedance and enable battery work normally at bending condition. Therefore, the LE-Li electrode presents the more stable electrochemical property than the pure Li anode in symmetric battery. Additionally, the Li–CO2 battery using LE-Li/TPE displays high discharge capacity of 22873 mAh g−1 and good rate capability under full discharge/charge condition. When operated at cut-off capacity, this cell can steadily run for 104 cycles with a small overpotential of

Following the guidance of nitrogenase, the natural iron-based catalysts with remarkably high activity in nitrogen reduction reaction (NRR) may be a talent option to develop artificial molecular mimics. However, the electrochemical NRR process of iron-based catalysts still suffers from the high overpotential, poor lifespan, and slow reaction kinetics of the hydrogenation process. Through a controllable etching and in-situ carbonating process, a Pt-doped FeP/C hollow nanorod catalysts was fabricated. Driven by the doped Pt atom, the catalyst solves the key kinetic problem about insufficient proton feeding in the process of nitrogen reduction, and actively transfers protons to intermediates of the hydrogenation steps in NRR. Moreover, the as-prepared catalyst presents the highest NH3 yield value of 10.22 μg h−1 cm−2 among multitudinous Fe based catalysts at lower potential of −0.05 V (vs. RHE) with an excellent Faraday efficiency (FE) of 15.3 %, which is higher than FeP/C without the Pt-driven proton-feeding effect, and the cathodic current density presents no significant change within 50 h. In addition, the density functional theory (DFT) and Attenuated total reflection surface-enhanced infrared absorption spectrum (ATR-SEIRAS) results verify the reaction path and protons-feeding kinetic process.

Supported by carbon materials and adjusting Ag surface states by metal oxides are two effective methods to promote the oxygen reduction reaction (ORR) performance of Ag-based catalysts. Herein, combining these two strategies, two kind of heterostructural electrocatalysts, carbon nanotubes-supported Ag/MoO2 (CNTs-Ag/MoO2) and carbon nanotubes-supported Ag/MnO2 (CNTs-Ag/MnO2) are constructed by facile two-step methods for the superior ORR catalytic activity in alkaline medium. Both CNTs-Ag/MoO2 and CNTs-Ag/MnO2 exhibit more positive onset potential and higher half-wave potential (~0.93 V and ~ 0.81 V (vs RHE) for CNTs-Ag/MoO2, ~0.99 V and ~ 0.86 V (vs RHE) for CNTs-Ag/MnO2), comparable and even superior to commercial Pt/C(~0.95 V and ~ 0.82 V(vs RHE)), which are benefit from Ag surface states regulation and the oxygen vacancy formation induced by the introduction of MoO2 or MnO2, as well as the enhanced electron transmission and dispersion of Ag/MoO2 or Ag/MnO2 resulted from the activated CNTs supporting. This work provides a useful reference to design efficient Ag-based ORR electrocatalysts with the superior performance.

Based on the Maxwell&rsquo, s equations, a finite element model is established to study the characteristics of electromagnetic field in the mold of billet and bloom continuous casting with electromagnetic stirring (M-EMS). A novel integral method for calculating electromagnetic torque is proposed to evaluate the stirring intensity of stirrer. In order to verify the accuracy of the model, a well-designed electromagnetic torque detecting device is fabricated. The predicted value of electromagnetic torque and magnetic flux density are consistent with the measured data. The optimum frequency is determined by the maximal electromagnetic torque of the strand. The effect of stirring current intensity and different stirrer positions along the length of mold on the electromagnetic field has been studied numerically. The results show that the optimum frequency is smaller when the copper tube of the mold is thicker and the section size is bigger. Besides, the electromagnetic torque of the strand is a quadratic function of the running current intensity. Moreover, the installation position of stirrer strongly affects the prediction of electromagnetic field distribution, further influencing the optimum frequency and the electromagnetic torque of strand.

Molybdenum disulfide (MoS2) exhibits the modest properties toward hydrogen evolution due to its poor electrical conductivity and a limited number of active sites. To make up for the defects in MoS2, we built hierarchical P-doped MoS2/NiS2@carbon hollow nanospheres (P–MoS/NiS@CHNS) electrocatalyst via one-step hydrothermal method owning to the priority of the reaction between Ni2+ and H2S. Motivated by high-efficient electron transfer at the interface of heterostructure and the activation of MoS2 by P dopant, P–MoS/NiS@CHNS exhibits optimal Gibbs free energies (ΔGH∗) and superior HER performance with low overpotential (ƞ10) of 110 ​mV ​at 10 ​mA ​cm−2 and small Tafel slope of 61 ​mV dec−1. The focus of this work is to optimize the HER performance of MoS2 through P-doping and heterostructure construction, which can further provide a reference for the design of MoS2 based catalysts.

Developing low-cost and high-performance nonprecious metal electrocatalysts for oxygen reduction (ORR) and oxygen evolution reaction (OER) are the crucial factors for advancing the renewable energy conversion and storage technologies, such as, Zn-air batteries. Here, we report on a novel templates approach to fabricate Co nanoislands activated Co,N-doped porous carbon nanospheres (Co/Co-Nx-PCNSs) bifunctional oxygen electrocatalyst with high density Co-Nx, and graphitic carbon shell active sites. The obtained Co/Co-Nx-PCNSs exhibit the highest ORR activity with large Eonset (onset-potential) of 0.98 V vs RHE, more positive E1/2 (half-wave potential) of 0.85 V vs RHE and large limited current density (j) of 6.6 mA cm−2 in 0.1 M KOH solution. For OER, they exhibit remarkably stable OER performance with potential as low as 1.58 V at 10.0 mA cm−2 and the small Tafel slop of 53 mV dec−1. The encouraging electrocatalytic performance can be ascribed to the high density of accessible active sites, low work function derived from Co nanoarchitecture activated graphitic carbon shell. The constructed Zn-air batteries display a large power density of 140 mW cm−2 and small potential gap 0.79 V. Strategy developed herein provides a promising technique for the rationally fabrication of efficient nonprecious metal electrocatalysts.

Semi-rigid 6-(carboxymethoxy)-2-naphthoic acid (H2CNA) was successfully synthesized as a ligand containing O-bridging atom. Six coordination polymers based on H2CNA ligand and transition metal ions were successfully synthesized under the hydrothermal or solvothermal conditions, which named [Zn(CNA)]n (1), [Cd(CNA) (H2O)]n (2), [Co(HCNA)2(H2O)4] (3), [Ni(HCNA)2(H2O)4] (4), [Cu(CNA) (H2O)]n (5), [Ni(CNA) (H2O)]n (6). Single crystal structural analysis revealed that 1, 2, 5 and 6 are shown as 2D structures, and 3–4 displays 0D structures. All the structures assembled into 3D supramolecular networks by hydrogen bonding interaction. The thermal stability, luminescent properties and UV–vis spectra of these coordination polymers were discussed in detail. In addition, 5 has good adsorption ability for Congo Red with good selectivity.

It is well known that the elements doping and morphology adjusting strategy are an effective ways to enhance the performance of supercapacitor electrode materials. In this work, using a Co-MOF as a precursor, a series of hollow-porous leaf-like V-doped nickel-cobalt layered double hydroxides (Ni-Co/V) nanosheets are successfully fabricated through a step-to-step etching process. The optimized Ni-Co/V-12-2 hollow leaf-like structure presents a typical hierarchical structure constructed by ultra-thin nanosheets and a hybrid pore of micro-/meso-porous with a BET surface area of 126.3 m2 g−1, which will provide the more active site and rich diffusion channels for enhanced energy storage performance. Therefore, the Ni-Co/V-12-2 electrode exhibits a high capacity of 161.4 mAh g−1 at 1 A g−1 and excellent cycle stability of maintaining 93.14% after 5600 cycles. Moreover, a hybrid supercapacitor with the Ni-Co/V-12-2 as the positive electrode and reduced graphene oxide (PPD/rGO) as the negative electrode, performs a high energy density of 55.22 Wh kg−1 at the power density of 0.375 kW kg−1.

The relationship between the popular hot charging associated surface crack sensitivity and the charging temperature was studied from the view of phase transformation. The austenite reversion with various charging temperatures was investigated through the thermal simulation experiments. And a two-dimensional representative volume element model was constructed to analyze the crack sensitivity related to microstructures. Compared to cold charging reversion, with the residual austenite in starting microstructure, the kinetics of hot charging reversion is slightly accelerated and the reversion behavior is changed. As the charging temperature increases, the austenite nucleation-growth from pearlite and ferrite grain boundaries are suppressed, while the austenitization through the growth of residual austenite is enhanced. The change of transformation behavior facilitates the formation of ferrite film during reversion through the morphological influence of austenitization modes. With the increasing of charging temperature, the film-like morphology of the evolved ferrite intensifies, especially in the two-phase temperature range. Consequently, the calculated crack sensitivity index rises sharply from 0.0006 to 0.029 when the charging temperature increases from Ar1 to Ar3 temperature, which is agreeable with the statistical production data. Additionally, it was observed that the incomplete γ → α → γ transformation cannot bring an effective austenite grain refining for the present steel.

The phase change material (PCM) microcapsule is a common high-performance storage technology of thermal energy. However, the organic wall with low thermal conductivity for PCM reduces the efficiency of heat storage and release. In this study, the novel carbon nanotube-doped phase change materials (C-PCMs) were developed. Scanning electron microscope test (SEM), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and the thermogravimetric analysis/infrared spectrometry (TG-IR) were used to analyse the composite structure and thermal performances. The results indicate that C-PCMs are small and regular in spherical shape. When C-PCMs suffer from heat, the shell can maintain integrity below 165 °C. Furthermore, the carbon nanotubes in the shell play as a channel to connect the inside with the outside and improve the efficiency of heat transfer. The DCS test of the samples showed that the latent heat of C-PCMs and PCMs were 112.25 J/g and 116.18 J/g, respectively. The initial phase transition temperature of C-PCMs is 28.97 °C, which is 0.5 °C lower than that of PCMs. The results of the model room test suggested that the composite filled with C-PCMs reduces indoor temperature fluctuations and exhibits the potential for enhancing energy savings and the thermal comfort of buildings.

An epoxy-modified oxidized starch-grafted styrene-acrylate (E-g-OS-P (BA-St)) emulsion was synthesized via soap-free core-shell emulsion polymerization without adding any solvent that could cause environmental problems. The emulsion exhibited excellent stability, chemical properties and mechanical performance. The synthesized emulsion was characterized by Fourier transform infrared spectroscopy (FTIR) and 13C NMR spectroscopy. Transmission electron microscopy (TEM) suggested that the OS-P (BA-St) latexes had certain umbrella structures and that the epoxy resin cross-linked a plurality of umbrella structures. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) showed that the thermal stability and glass transition temperature (Tg) of the polymer became higher as the content of epoxy resin increased. Atomic force microscopy (AFM) was utilized to characterize the surface morphology of the films. The film with 10% epoxy resin (based on the mass of monomers) possessed superior tensile strength and elongation, exhibiting a nearly 100% increase in tensile strength relative to that of neat latexes without epoxy. Additionally, the mechanism of polymerization and film formation of the E-g-OS-P (BA-St) emulsion were analysed.

Based on the Maxwell’s equations and a revised low-Reynolds number k-e turbulence model, a coupled three-dimensional numerical model has been developed to describe the electromagnetic field, fluid flow and solidification in a bloom continuous casting mould with electromagnetic stirring (M-EMS). The stirring electric current effects on the turbulent flow, temperature distribution and shell growth are investigated numerically. According to the simulation result, the electromagnetic force has a circumferential distribution on the strand transverse section, and a swirling flow field along the axial direction is observed in the mould region with the application of M-EMS, which changes the flow pattern of melt in the mould significantly and promotes the superheat dissipation of the molten steel. Moreover, overlarge current intensity will generate an inhomogeneous solidified shell at the exit of the mould due to the tangential velocity of the swirling flow and the installed position of the M-EMS.

In this article, smoke suppression and synergistic flame retardancy properties of zinc borate (ZB) and diantimony trioxide (Sb2O3) in epoxy-based intumescent fire-retardant (IFR) coating were investigated based on cone calorimeter test, smoke density test, scanning electron microscopy, thermogravimetric and Fourier transform infrared spectroscopic analyses. The measurement results of the dynamic combustion and smoke production behaviors and static smoke production behaviors of these IFR coatings showed that the values of heat release rate, smoke production rate, smoke factor and fire growth index all decreased significantly with the addition of ZB and Sb2O3. At the same time, the specific optical densities were remarkably reduced due to the existence of ZB and Sb2O3. These attractive data clearly demonstrated that the ZB and Sb2O3 had a good effect on smoke suppression and synergistic flame retardancy of the IFR coating. Besides, the scanning electron microscopy and the infrared spectroscopic analyses during coating thermal degradation were also carried out to explore the outstanding synergistic smoke suppression and flame retardancy mechanism of ZB and Sb2O3. With the melt of ZB and Sb2O3, a lot of heat was absorbed, and then, the glassy protective layer associated with the graphite char would effectively retard heat and suppress smoke.

In this paper, fumed silica has been used as smoke suppression and flame-retardant synergism in thermoplastic polyurethane (TPU) composites based on ammonium polyphosphate (APP). And, the synergistic smoke suppression property and flame-retardant effect of fumed silica in flame-retardant TPU composites are mainly intensively investigated by several methods, including smoke density test (SDT), cone calorimeter test (CCT), scanning electron microscopy (SEM), limiting oxygen index, and thermogravimetric analysis. The results of SDT show that fumed silica can significantly decrease smoke production of flame-retardant TPU composites. The results of CCT present that the addition of fumed silica can effectively reduce smoke production rate, total smoke release, smoke factor, heat release rate, and mass loss in the combustion process of flame-retardant TPU composites. The SEM results show that fumed silica can improve the quality of char residue after cone calorimeter test. All the results show that fumed silica is an effective smoke suppression agent and a good flame-retardant synergism with APP in TPU composites.

A novel organic–inorganic intumescent flame retardant, expandable graphite modified with charring agent (EGM), was synthesized using expandable graphite (EG), phosphorus oxychloride, and pentaerythritol. Then, EGM was used as flame retardant for epoxy resin. And the flame-retardant properties of epoxy composites were investigated by cone calorimeter test (CCT). The thermal degradation behaviors of epoxy composites were studied by thermogravimetric analysis (TG) in nitrogen atmosphere. And the pyrolysis kinetics of the composites was investigated using Kissinger and Flynn–Wall–Ozawa methods. The CCT result indicated that EGM can reduce the heat release rate and smoke production rate more than EG in flame-retardant epoxy composites: a more compact char residue formed on the surface of the sample with EGM than that of the sample with EG during the combustion process. The TG result showed that the sample with EGM has higher thermal stability than the sample with EG. And the data calculated from Kissinger and Flynn–Wall–Ozawa methods showed that both EP-0 and EP-3 had two thermal degradation stages; EGM can improve the E a value of epoxy resins.

Thermoplastic vulcanizates (TPVs) based on high impact polystyrene (HIPS)/styrene-butadiene-styrene block copolymer (SBS)/styrene-butadiene rubber (SBR) blends were prepared by dynamic vulcanization, with the TPVs being reinforced by carbon black (CB). Experimental results indicated that mechanical properties of dynamically vulcanized HIPS/SBS/SBR blends were enhanced remarkably by the incorporation of CB. The fracture surface morphology of the reinforced HIPS/SBS/SBR/CB TPVs was relatively flat. The Mullins effect could be observed in the stress-strain curves of HIPS/SBS/SBR TPVs and HIPS/SBS/SBR/CB TPVs during the uniaxial loading-unloading cycles. Compared with HIPS/SBS/SBR TPVs, CB-reinforced HIPS/SBS/SBR TPVs had the relatively higher stress, residual strain and internal friction loss.

In this work, an organic inorganic hybrid intumescent flame retardant (functionalized expandable graphite, FEG) was synthesized and characterized by Fourier transform infrared spectrometry (FTIR). The flame retardant effects of FEG in silicone rubber (SR) composites were investigated by cone calorimeter test (CCT), and the thermal stability of SR composites was studied using TGA. The CCT results showed that FEG can effectively reduce the flammable properties including peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), total smoke release (TSR), and smoke factor (SF). An improvement of thermal stability of SR/FEG was also observed. Compared with EG, FEG can further reduce THR, SPR, and TSR of SR/FEG composites in combustion process. Moreover, there is a more obvious intumescent char layer formed from the sample with FEG than the sample with EG at the same loading in SR composites. Copyright © 2014 John Wiley & Sons, Ltd.

A series of intumescent flame-retardant epoxy resins (IFREP) were prepared based on bisphenol A epoxy resin (EP) as matrix resin, ammonium polyphosphate (APP) and pentaerythritol as intumescent flame retardants (IFRs), and ferrite yellow (goethite) as smoke suppressant. Then, the synergistic flame-retardant and smoke suppression properties of α-FeOOH on IFR epoxy composites were intensively investigated using cone calorimeter test and scanning electron microscopy. The thermal degradation process of IFR epoxy composites were studied using thermogravimetric analysis–infrared spectrometry under nitrogen atmosphere. Then, the pyrolysis kinetics parameters were investigated using Kissinger and Flynn–Wall–Ozawa methods. The results showed that goethite can significantly reduce heat release rate, total heat release, smoke production rate, and total smoke release. There are obvious synergistic flame-retardant and smoke suppression effects between goethite and IFRs in epoxy composites.

New silicone rubbers(SR)-based hybrid material containing intumescent flame retardant (IFR) and ferric hydroxide (FeOOH) has been developed in order to improve flame retardancy of SR. The synergistic effects of FeOOH with IFR in halogen-free flame retardant SR/IFR blends have been studied by cone calorimeter test (CCT) and thermogravimetric analysis (TG). The data obtained from the CCT indicate that the SR/IFR/FeOOH sample with 4.0 mass% FeOOH has the lowest HRR, SPR, TSR, THR, and SF among all samples. The digital photo graphs give positive evidence that there is a synergistic effect between IFR with FeOOH. The TG results reveal that FeOOH can enhance the thermal stability of SR/IFR/FeOOH at high temperature. Besides the traditional investigations on cone calorimeter tests, an intensive study on the thermo-degradation kinetics was carried out to reveal the mechanism of the outstanding flame retarding performance of the SR/IFR/FeOOH. FeOOH can improve the flame retardancy, increase the thermal stability during the whole process of degradation, and strengthen the ability to form a thermally stable and condensed barrier for heat and mass transfer. These attractive features of SR/IFR/FeOOH suggest that the method proposed herein is a good approach to prepare very effective flame retardants and corresponding super flame retarding SR.

A series of flame retardant ethylene-vinyl acetate (EVA) composites, with different content of magnesium hydroxide (MH) and hollow glass microspheres (HGM), have been prepared. The synergistic flame retardant effects of HGM with MH in EVA/MH blends have been studied by limiting oxygen index (LOI), UL-94 tests, cone calorimeter test (CCT), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM), respectively. The LOI and UL-94 results show that when 2.00 wt% magnesium hydroxide (MH) is substituted with HGM, the LOI value can be raised to the maximum value of 42.1 among all samples. The data obtained from the CCT test indicate the heat release rate (HRR) of EVA/MH/HGM sample with 1.00 wt% HGM reduced by 37% when compared with EVA/MH sample without HGM. The digital photo graphs and scanning electron microscope (SEM) of char residues after CCT give positive evidence that the synergistic flame retardant effects between HGM and MH can be described that HGM mixed with MH can decrease the melt viscosity of EVA/MH/HGM, and promote the homogeneous dispersion of MH. HGM also can promote the formation of compact charred layers and prevent the charred layers from cracking, which effectively protects the underlying materials from burning. The TGA results reveal that EVA/MH/HGM samples show higher thermal stability at high temperature than EVA/MH sample.

Nowadays, reducing the fire hazard of thermoplastic polyurethane (TPU) is an important research direction in the fields of fire safety materials. In this article, hollow glass microsphere (HGM) was used to reduce the fire hazard of TPU in combustion process. The fire characteristics including smoke and heat production of TPU composites were evaluated using smoke density test (SDT) and cone calorimeter test (CCT). And the thermal decomposition and flammable properties were further studied using thermogravimetric analysis/infrared spectrometry (TG-IR) and limiting oxygen index (LOI), etc. The SDT results showed that the luminous flux (LF) of TPU4 containing 2.00wt% HGM was up to 24% at the end of test without flame, which is much higher than that of TPU0 (5%). And, the CCT results indicated that 2.00wt% HGM could make the total smoke release (TSR) decrease from 1019m2/m2 (TPU0) to 757m2/m2 (TPU4), reduced by 26%. The TG-IR results confirmed that HGM could improve the thermal stability of composites and reduce the production of some toxic gases. The above results illustrated HGM had a good prospect in reducing the fire hazard for TPU.

Novel fluorinated polyhedral oligomeric silsesquioxane (POSS) acrylic copolymers were synthesized by the radical solution polymerization. The superhydrophobic coating was prepared using a one-step breath figure method. Chemical constitution, morphology, hydrophobicity, and anticorrosion ability of as-prepared coatings were investigated by the corresponding equipment. The addition of proper fluorinated POSS can synchronously promote the formation of the micro-nano convex structure and the enrichment of fluorinated groups on the surface. Compared to commercial acrylic coating, the fluorinated POSS coating presented enhanced anticorrosion performance. The impedance was the highest and the corrosion current density was the lowest for superhydrophobic coating with 25 wt % fluorinated POSS.

Melamine salt of pentaerythriol phosphate (MPP), as a new single molecule intumescent flame-retardant, was prepared from pentaerythritol, phosphoric acid, and melamine, and then incorporated into polypropylene (PP) with organic montmorillonite (OMT) to obtain flame retardant PP/MPP/OMT composites. The flammability and combustion behavior of flame retardant PP composites were characterized by using LOI, UL-94 test, and cone calorimeter, respectively. The results showed that the flame retardant properties of the composite containing 29.0 wt% MPP and 1.0 wt% OMT are the best among all the composites. The digital photographs after cone calorimeter test demonstrated that moderate OMT could promote to form the homogenous and compact intumescent char layer.

To study the influence of the T31 content on the combustion properties and thermal degradation behaviors of flame-retardant epoxy composites, a series of flame-retardant epoxy composites were prepared using E-44 epoxy resin as matrix, T31 curing agent as curing agent, and intumescent flame retardant (IFR, based on phosphorus acid, melamine, and pentaerythritol) as flame retardant. The influence of T31 content on combustion behaviors and thermal degradation properties of the flame-retardant epoxy composites were studied using cone calorimeter test (CCT) and thermal-gravimetric analysis (TG), respectively. The cone calorimeter test results indicate that the decrease of T31 can significantly decrease the HRR, THR, SPR, and enhance the char residue of the epoxy composites. EP-4 with 7.0 wt% T31 shows the lowest HRR, SPR and the highest char residue. Furthermore, the TG results indicate that the EP-4 has the highest char residue among all the epoxy composites.

Flame retardant polyurethane foams materials (PUFM) composites were prepared using tricresyl phosphate (TCP) as flame retardant. The combustion and thermal degradation behaviors of flame retardant PUFM composites were investigated by microscale combustion calorimetry (MCC) and thermogravimetric analysis/infrared spectrometry (TG–IR). The results showed that TCP had excellent flame retardant abilities for PUFM. The TGA curves suggested that TCP has good ability of char formation. The volatilized products formed on thermal degradation of flame retardant PUFM indicated that the volatilized products are mainly carbonyl compounds, CO2, and esters. In addition, TCP can greatly reduce the toxic gases containing NCO groups and increase CO2 as nonflammable gases when it is incorporated into the composites.

Flame retardant epoxy resin (FREP) were synthesized from phosphoric acid and bisphenol A epoxy resin (BAEP). The structure of the FREP was characterized using FTIR and 31P NMR. Then, several FREP/BAEP mass ratios were used to obtain materials with different phosphorus contents. The properties of the thermosetting materials were evaluated by limiting oxygen index, UL 94, cone calorimeter test, and thermogravimetric analysis. The results showed that the heat release rates and smoke production rates decreased greatly, and char residue increased with the increasing of FREP. It indicates that good flame retardant properties are related to the formation of a protective phosphorus-rich char layer.