Showing papers on "Cone calorimeter published in 2020"
TL;DR: Tannin (TA) is firstly used to functionalize black phosphorous (BP) nanosheets to improve the ambient stability and toxic suppression, thus decreasing the fire hazards of polymer materials, and promotes the promising potentials of BP nanOSheets in the fire safety application of polymer composites.
91 citations
TL;DR: The flame retardancy of EP thermosets modified by CCD was dramatically improved and char residue for EP/10 % CCD thermoset possessed dense and compact structure which played a positive effect in blocking the exchange of heat and gas.
90 citations
TL;DR: In this paper, an organic/inorganic phosphorus-nitrogen-silicon flame retardant (DPHK) was synthesized by Kabachnik-Fields reaction and the sol-gel method, then it was used as a reactive flame retardant to prepare flame-retardant and smoke-suppressant epoxy resins (EP).
89 citations
TL;DR: In this article, a nitrogen/sulfur-containing DOPO-based oligomer (SFG) for highly efficient flame-retardant epoxy resin was successfully synthesized via a facile one-pot method with DopO, sulfaguanidine and p-phthalaldehyde.
78 citations
TL;DR: In this article, a silicone resin (poly-DDPM) was synthesized and coated on the surface of rigid polyurethane foam in association with expandable graphite (EG) via brush painting in order to improve its flame retardancy with minimal damage to the inherent mechanical property.
64 citations
TL;DR: In this article, a hydrophobic and oleophilic flexible polyurethane foam modified with metal organic framework (MFPU) was successfully fabricated through in situ self-assembly method.
60 citations
TL;DR: In this article, a phosphorus-grafted hexadecanol was blended with pentaerythritol phosphate (PEPA) to prepare flame-retardant phase change material (FRPCM).
55 citations
TL;DR: In this paper, a flame-retardant carbon foam/epoxy (FREP-CF) composite is proposed to resist approximately 1000°C flame for 10min with the temperature on the back side lower than 200°C, which is much better than the original epoxy resin.
Abstract: Multifunctional epoxy composites with low flammability, high ablation resistance, superior electrical conductivity and outstanding electromagnetic interference (EMI) shielding performances are prepared by a two-step procedure. The first step involves pyrolysis of lignin-resorcinol-glyoxal pre-polymer into carbon foams, while the second step is infiltrating flame retardant epoxy resins (FREP) into the highly porous carbon foams. SEM images show that the three-dimensional network microstructure of carbon foams is integrally preserved during infiltration by the epoxy resins, which could serve as an effective pathway for electron transport. For the flame-retardant carbon foam/epoxy (FREP-CF) composite, a UL-94 V-0 classification is achieved. In the cone calorimeter measurement, the peak heat release rate and the total heat release of the FREP-CF composite are reduced by 64% and 37%, respectively, compared to those of the original epoxy resin. The FREP-CF composite can resist approximately 1000 °C flame for 10 min with the temperature on the back side lower than 200 °C, which is much better than the EP-CF composite. Additionally, a notable electrical conductivity of 216 S/m and a superior EMI shielding effectiveness of 33.5 dB are achieved for the FREP-CF composite. This multifunctional epoxy composite enables it a promising candidate for electronics, aerospace and transportation applications.
53 citations
TL;DR: In this article, a novel monomer with six functional epoxy groups was successfully synthesized by combining eugenol with hexachlorocyclotriphosphazene.
52 citations
TL;DR: In this article, the flame-retardant glass fiber reinforced epoxy composites were produced with low cost environmentally friendly flame retardant (red phosphorus) and smoke suppressants (zinc borate and aluminum three hydrate) instead of high-cost and harmful halogenated flame retardants.
49 citations
TL;DR: In this article, a fire assessment model has been developed to provide a better understanding of the flame propagation, toxic gases and smoke generations of polymer composites, which is capable of predicting and visualising fire development and emitting gas volatiles.
Abstract: A fire assessment model has been developed to provide a better understanding of the flame propagation, toxic gases and smoke generations of polymer composites. In this study, the effectiveness of the Chitosan/Graphene Oxide layer-by-layer fire retardant coating on flexible polyurethane foam was investigated experimentally and numerically via Cone Calorimetry. To generate quality pyrolysis kinetics to enhance the accuracy of the model, a systematic framework to extract TGA data is proposed involving the Kissinger–Akahira–Sunose method followed by Genetic Algorithm, with less than 5% of RMS error against experimental data. The proposed fire model is capable of predicting and visualising fire development and emitting gas volatiles.
TL;DR: A low loading microporous boron-based intumescent macrocycle (BMC) flame retardant was prepared and incorporated into PLA to reduce its flammability, improve the mechanical properties, and enhance its ultraviolet protection.
01 Jan 2020
TL;DR: In this paper, a lignin-based phenolic resin was modified with whisker silicon and preparation of the phenolic foam was carried out, which was characterized by Fourier transform infrared spectroscopy (FT-IR), TGA, thermal conductivity test, limit oxygen index (LOI) analyzer and cone calorimeter.
Abstract: In this study, lignin-based phenolic resin was modified with whisker silicon and preparation of the phenolic foam was carried out. The resin and foam materials were characterized by Fourier transform infrared spectroscopy (FT-IR), thermo gravimetric analyzer (TGA), thermal conductivity test, limit oxygen index (LOI) analyzer and cone calorimeter. The results showed that when the content of lignin and whisker silicon increased, the oxygen index of the foam increases and the calorific value of combustion decreased. However, if the amount of lignin increased, the open porosity of the foam and the thermal conductivity increased. When the lignin substitution rate was 30% and the whisker silicon addition amount was 1%, the phenolic foam (PF4) had the best performance: the 57.1% mass lost at 600 °C and the thermal stability was 16.8% higher than that of ordinary resin. The LOI was 49.6%, and 39.3% higher than that of ordinary phenolic foam.
TL;DR: In this article, the effect of different loadings of the fillers on the flame-retardant PU foams was examined, and the results showed that incorporated fillers can form an intumescent char layer during combustion which improves the reaction to fire of the composite foams.
TL;DR: It was demonstrated that the MOF composite (IL@NH2-MIL-101(Al), designed through the generated cooperative role of MOF, is able to effectively improve the fire safety of EP at low additions (3 wt. %).
Abstract: Metal-organic frameworks (MOFs) have shown great potential in flame retardant applications; however, strategies for fully exploiting the advantages of MOFs in order to further enhance the flame retardant performance are still in high demand. Herein, a novel MOF composite was designed through the generated cooperative role of MOF (NH2-MIL-101(Al)) and a phosphorus-nitrogen-containing ionic liquid ([DPP-NC3bim][PMO]). The ionic liquid (IL) was composed of imidazole cation modified with diphenylphosphinic group (DPP) and phosphomolybdic acid (PMoA) anions, which can trap the degrading polymer radicals and reduce the smoke emission. The MOF acts as a porous host and can avoid the agglomeration of ionic liquid. Meanwhile, the -NH2 groups of NH2-MIL-101(Al) can increase the compatibility with epoxy resin (EP). The framework is expected to act as an efficient insulating barrier to suppress the flame spread. It was demonstrated that the MOF composite (IL@NH2-MIL-101(Al)) is able to effectively improve the fire safety of EP at low additions (3 wt. %). The LOI value of EP/IL@NH2-MIL-101(Al) increased to 29.8%. The cone calorimeter results showed a decreased heat release rate (51.2%), smoke production rate (37.8%), and CO release rate (44.8%) of EP/IL@NH2-MIL-101(Al) with respect to those of neat EP. This strategy can be extended to design other advanced materials for flame retardant.
TL;DR: In this paper, a novel phosphorus and nitrogen containing flame retardant named 1,4-bis(Diethyl methylenephosphonate) piperazine (BDEMPP) was synthesized.
TL;DR: Li-Ph-POSS as discussed by the authors is a hepta-phenyl POSS comprised of incompletely condensed Si−OH and Si−O−Li groups, which is a polyhedral oligomeric phenyl silsesquioxane.
TL;DR: In this article, an environmentally friendly flame-retardant, referred to as FRC-Si, was developed to improve the fire resistance of asphalt binder without compromising mixture performance, and a multi-criteria decision analysis method was employed to find the optimal proportion of the combined EG, MH, CH, and APP to be 5:5:4:9, respectively.
TL;DR: In this article, a flexible siloxane chain containing phosphaphenanthrene structure (KHDOPO) was chemically grafted onto epoxy resin macromolecules, which exhibited satisfactory flame retardancy and thermal stability.
TL;DR: MgAlCO3-layered double hydroxides (LDHs) were respectively added as a synergistic agent to intumescent fire retardant (IFR) coatings.
TL;DR: In this paper, a novel organophosphorus compound named DDPPM has been synthesized and used as co-curing agent to obtain inherent flame-retardant epoxy resins.
TL;DR: In this paper, microcrystalline cellulose (MCC) extracted from bamboo powder was used as bio-based carbon source in intumescent system to improve both the dispersibility and compatibility of in/with polylactic acid (PLA).
Abstract: Microcrystalline cellulose (MCC) extracted from bamboo powder was used as bio-based carbon source in intumescent system. Before using, MCC was modified with methacrylic acid (MA) by grafting polymerization to prepare MA-MCC, which may improve both the dispersibility and compatibility of in/with polylactic acid (PLA). MA-MCC, together with ammonium polyphosphate, was blended into PLA by melt compounding. The flame retardant properties of the composites were characterized by the limiting oxygen index (LOI), UL-94 vertical burning test and cone calorimeter test. The results showed that the LOI of PLA composite sample containing 3% MA-MCC and 7% APP could reach up to 26.8% and pass V-0 rating in UL-94 test. The addition of APP and MA-MCC could also decrease the peak heat release rate from 556 kW/m2 of neat PLA to 456 kW/m2 and form a continuous, dense, homogeneous residue char to prevent PLA from further burning. Thermogravimetric analysis showed that the presence of APP and MA-MCC could enhance the thermal stability of the composites, which is also essential for the improvement of fire performance. The mechanical properties of PLA composites were also improved with the unnotched impact strength increased to 8.16 kJ/m2 and Young’s modulus increased to 1612.8 MPa. The possible mechanisms for the improvement of flame retardancy and mechanical properties had also been proposed.
TL;DR: In this paper, pyrophosphoric acid (PPA) was used as acid and gas source and pentaerythritol (PER) as charring agent to form an intumescent flame retardant (IFR) system which was applied to improve the flame retardancy of polypropylene (PP).
Abstract: Cytosine pyrophosphate (PPA-C) was prepared by using pyrophosphoric acid (PPA) and cytosine (C). The structure, morphology and thermal stability of PPA-C were analyzed by using Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy and thermogravimetric analysis (TGA). The PPA-C was used as acid and gas source and pentaerythritol (PER) as charring agent to form an intumescent flame retardant (IFR) system which was applied to improve the flame retardancy of polypropylene (PP). The flame retardancy and thermal degradation behaviors of PP/IFR composites were investigated by vertical combustion (UL-94), limiting oxygen index (LOI) and cone calorimeter (cone), TGA etc. The PPA-C and PER have good synergistic effects on improving the flame retardancy of PP which is better than that of commercial ammonium polyphosphate (APP) and PER system. The PP/IFR composites with 18 wt% PPA-C/PER (3:1) achieves the UL-94 V-0 rating and a LOI value of 28.8 vol%. The PPA-C reacts with PER to form -P-O-C and -P-C- during combustion which helps the formation of intumescent char layer. In addition, the IFR makes PP degrade in advance and form more char residues at high temperature. Proper ratio and amount of PPA-C/PER promotes the formation of intumescent char layer without defects during combustion, reduces the heat release rate and delays the thermal degradation of PP composites, thus improves the flame retardancy of PP.
TL;DR: In this paper, an organic phosphorus and metal oxide hybrid compound named P-MnMo6 was prepared through combining 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10oxide (DOPO) with polyoxometalate (POM).
Abstract: Transition metal oxides based catalytic carbonization have been proved to be a promising way to enhance polymer flame retardancy, but finding better way to introduce organic phosphorus and transition metal oxide hybrids into polymer matrix to form nanocomposites is still a great challenge. In this work, an organic phosphorus and metal oxide hybrid compound named P–MnMo6 was prepared through combining 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) with polyoxometalate (POM). The as-prepared P–MnMo6 had a center of [MnMo6O18]3- and was used as the precursor of transition metal oxides to improve the flame retardancy of epoxy resin (EP). With the aid of the organic modification, the addition of P–MnMo6 not only maintained the transparency of EP but also enhanced the dynamic mechanical properties. Notably, the thermogravimetric analysis showed that the char yield of EP/P–MnMo6 composite increased significantly. Besides, epoxy with 8 wt% addition of P–MnMo6 passed the vertical burning grade (UL-94) V-0 rating with the limiting oxygen index (LOI) value of 30.4%. Cone calorimeter test indicated the peak heat release rate of EP/P–MnMo6-4 decreased by 41%. Meanwhile, smoke products and CO were greatly suppressed. In addition, the potential flame retardancy mechanism of P–MnMo6 in epoxy matrix was proposed.
TL;DR: In this paper, the performance of a series of phosphorus-based flame retardant additives with and without sulfur (thio-ethers or sulfones) in their structure are compared.
TL;DR: In this article, the authors proposed a combined synergistic flame-retardant mechanism by the barrier effect of expandable graphite (EG) in condense phase and radical capture mechanism of FR1 in gas phase.
TL;DR: In this paper, a high heat storage capacity form-stable composite phase change material (CPCM) with enhanced flame retardancy that integrated modified glass fibers with formstable PCM was proposed.
TL;DR: In this paper, a novel biomass-based flame retardant derived from vitamin C (VCFR) was designed and synthesized, and the lyocell fabrics were finished with VCFR through esterification to fabricate durable flame-resistant fabrics (RF-lyocell).
Abstract: Lyocell fibers, one of the green and regenerated cellulose fibers, are widely used in the textile fields. However, lyocell fibers are highly flammable which will cause fire accidents. Herein, a novel biomass-based flame retardant derived from vitamin C (VCFR) was designed and synthesized. Then, the lyocell fabrics were finished with VCFR through esterification to fabricate durable flame retardant lyocell fabrics (RF-lyocell). The structure of the different fabrics was characterized by X-ray photoelectron spectroscopy and Fourier transform infrared analysis analysis. The limiting oxygen index value of the FR-lyocell was as high as 39.8%, which still remained 26.4% after 30 washing cycles, indicating excellent flame retardancy and durability. Thermogravimetric-Fourier transform infrared analysis proved that non-combustion compounds, such as CO2 and water were generated, and provided an obvious flame retardant effect in the gas phase. Cone calorimeter tests showed that the peak of heat release rate and total heat release had a reduction of 89.5% and 54.5%, respectively. These results suggested that VCFR can be used as an effective biomass-based flame retardant for lyocell fabrics.
TL;DR: In this article, a halogen-free, organic boron/nitrogen compound, 2,4,6-tris-(4-boronphenoxy)-(1,3,5)-triazine (TNB), was synthesized.