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The salt impurities in graphite oxide (GO) or graphene oxide usually affects their properties and application. Here, thermal stability and hazard (fire risk) of graphite oxide (GO) assembled films with salt impurities including K 2 SO 4 and MnSO 4 were investigated by C80 micro-calorimeter, thermogravimetric analysis combined with infrared spectrometry techniques. It was found that the metal impurities can significantly increase the release of flammable CO during thermal decomposition of GO, even at a very low content. The mechanisms of thermal instability and fire risk of GO containing metal salts was proposed. [ABSTRACT FROM AUTHOR]

A reactive cyclic phosphorus-containing monomer (ethyl acrylate cyclic glycol phosphate; EACGP) was synthesized in a facile way and various amounts of EACGP were combined with unsaturated polyester by radical bulk polymerization. The resulting flame-retardant unsaturated polyester resin (UPR) samples were investigated using thermogravimetric analysis, limiting oxygen index (LOI), and microscale combustion calorimetry tests. Due to the high phosphorus content of EACGP, incorporation of this monomer led to a marked decrease in the peak heat release rate and the total heat release, an increase in the LOI and the combustion char formation. Furthermore, real-time Fourier transform infrared spectroscopy was employed to investigate the thermooxidative degradation behavior of UPRs and the charring effect of EACGP as well as the UPR char morphology was studied, illustrating the flame retardancy mechanism in UPR. [ABSTRACT FROM PUBLISHER]

A novelreactive phosphorus-containing acrylate (ODOPB-AC) was successfullysynthesized and characterized, and the flame retardant unsaturatedpolyester resins (FR-UPR) with various amounts of ODOPB-AC were prepared.The thermal decomposition and flame retardant properties of sampleswere investigated by thermogravimetric analysis (TGA), limiting oxygenindex (LOI), and microscale combustion calorimetry (MCC). As the ODOPB-ACcontent increased, the LOI value of FR-UPR was increased, while thevalue of peak heat release rate (PHRR) and total heat release (THR)were reduced. The evolved gas analysis and condensed thermo-oxidativedegradation process of UPR and FR-UPR were monitored by thermogravimetricanalysis/infrared spectrometry (TG-IR) and real-time infrared spectrometry(RT-IR), providing insight into the thermal degradation mechanism.ODOPB-AC acted in the gas phase through flame inhibition and in thecondensed phase through charring. Moreover, scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy (XPS) were used to explorethe morphology and chemical components of the char. [ABSTRACT FROM AUTHOR]

A novel natural material-based flame retardant melamine chitosan phosphate (MPCS) has been prepared. Its impact on thermal properties and flammability performance of polyvinyl alcohol (PVA) was analyzed. Thermogravimetric analysis data exhibited that MPCS enhanced the thermal stability of materials at high temperature. The results of thermogravimetric analysis/infrared spectrometry (TGA-IR) showed that MPCS decreased the yield of flammable volatilized products greatly. Microscale combustion calorimetry (MCC) data showed that peak heat release rate (PHRR), total heat release (THR) and heat release capacity (HRC) all reduced, which indicated that MPCS improved the flame retardancy of materials. [ABSTRACT FROM AUTHOR]

A renewable carbonization agent based compound nickelchitosan phosphate (NiPCS) has been prepared, which was the combinationof flame retardant and synergist. Its effect on thermal propertiesand flammability of poly(vinyl alcohol) (PVA) has been investigated.Microscale combustion calorimetry (MCC) test proved that NiPCS candecrease the intensities of heat release rate (PHRR) and total heatrelease rate (THR) greatly. Thermogravimetric analysis (TGA) resultsindicated that NiPCS possessed a high formation of char. With theincrease of the flame retardant, the thermal stability of materialsenhanced in high temperature. Real time Fourier transform infrared(RT-IR) data confirmed that the flame retardant can promote the dehydrationeffect as well as accelerate the char forming. The volatilized productsand the synergistic effect of nickel on thermal properties were bothinvestigated with thermogravimetric analysis/infrared spectrometry(TGA-IR) and laser Raman spectroscopy (LRS). The results revealedthat nickel restrained the thermal degradation of materials as wellas improved the structural organization level of char. [ABSTRACT FROM AUTHOR]

A novel phosphorus, nitrogen-containing compound, poly(4, 4′-diaminodiphenyl methane phenyl dichlorophosphate) (PDMPD) with high thermal stability was synthesized. The PDMPD was then incorporated into polystyrene (PS) to be used as halogen-free flame retardant. Moreover, small amounts of two boron-containing compounds, Zinc borate (ZnB) and boron phosphate (BP) were combined with PDMPD,to explore effective flame-retardant formulations for PS. The flammability and the thermal properties of the composites were evaluated using limiting oxygen index (LOI) test, microscale combustion calorimeter (MCC) and thermogravimetric analysis (TGA) respectively. A Fourier transform infrared (FTIR) spectroscopy coupled with a thermogravimetric analyzer (TG-IR) was also used to study the gas phase from the degradation of PS composites. Furthermore, the char residues of the samples were investigated by scanning electron microscopy (SEM) and FTIR. The results showed that the incorporation of PDMPD can significantly decrease the flammability of virgin PS, and enhance the thermal stability at high temperature region, in both nitrogen and air atmosphere. A combination of PDMPD with small amounts of boron compounds can further decrease the flammability. [ABSTRACT FROM AUTHOR]

Abstract: This work aims to develop glass-fibre reinforced poly(ethylene terephthalate) (PET/GF) composites with significantly improved flame retardancy using aluminum hypophosphite (AHP) and melamine cyanurate (MC). Microscale combustion calorimetry (MCC) and thermal gravimetric analysis/infrared spectrometry (TG-IR) technique were used to investigate the potential fire hazards of various PET/GF composites. For the PET/GF composites with a low loading of the flame retardant mixture, the heat release capacity (HRC) which is an indicator of a material fire hazard reduced by 47%, meanwhile, the intensities of a variety of combustible or toxic gases detected by TG-IR technique were remarkably decreased. A loading of 10wt.% AHP alone or its combination with MC could give the PET/GF composites high limited oxygen index and V-0 classification in UL-94 test. Thermal decomposition and residue analysis revealed that the flame retardancy of PET/GF composites is enhanced by the condensed-phase action of AHP and the gas-phase dilution effect of MC. [Copyright &y& Elsevier]

Abstract: Poly(DOPO substituted dihydroxyl phenyl pentaerythritol diphosphonate) (PFR) was synthesized via the reaction between 10-(2,5-dihydroxyl-phenyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO-BQ) and pentaerythritol diphosphonate dichloride (SPDPC). The structures of PFR were characterized by Fourier transformed infrared (FTIR) spectroscopy and 1H nuclear magnetic resonance (1H NMR). Thermal degradation behaviors and flame retardant properties of the epoxy resin (ER)/PFR systems were investigated from the thermogravimetric analysis (TGA), UL-94 test and the limiting oxygen index (LOI) test. Moreover, the surface morphology of the char residue was studied by scanning electron microscopy (SEM). When the PFR content reached 10wt%, the epoxy resin system met the UL-94 V0 classification and the LOI value of 30.2. The microscale combustion calorimetry (MCC) was used to evaluate the combustion behaviors of the ER/PFR. It was found that the addition of PFR obviously decreased the value of peak heat release rate and total heat release of the hybrids. The TGA results showed that the epoxy resin with 10wt% PFR exhibited high char yields. The high char yields and the high limiting oxygen index values were found to certify the excellent flame retardancy of this phosphorus-containing epoxy resin. [ABSTRACT FROM AUTHOR]

Abstract: A novel intumescent flame retardant piperazine-N,N′-bis(acryloxyethylaryl-phosphoramidate) (N-PBAAP) containing phosphorus and nitrogen used for UV curable coating was synthesized and characterized by Fourier transform infrared spectrometry (FTIR), 1H and 31P nuclear magnetic resonances (NMRs). The thermal degradation and volatilized products of the N-PBAAP cured film were monitored by real time Fourier transform infrared (RT-FTIR) and thermal gravimetric-Fourier transform infrared (TG-FTIR) technique, respectively. Scanning electron microscopy (SEM) was employed to investigate the surface morphology of the residual char. And possible mechanism for the thermal degradation of N-PBAAP film was proposed. To investigate the flame retardancy of N-PBAAP in UV curable coatings, a series of UV curable intumescent flame retardant resins were obtained by blending N-PBAAP with EA (epoxy acrylate oligomer) in different ratios. The flammability and thermal properties of the cured films were studied by Microscale Combustion Calorimeter (MCC) and thermogravimetric analysis (TGA). In MCC test, the peak heat release rates (pHRRs) of the blends were all lowered by the addition of N-PBAAP comparing with the pure EA. And TG results revealed that N-PBAAP can greatly enhance the char residues of EA films at high temperature region. [ABSTRACT FROM AUTHOR]

Abstract: The influences of expanded graphite (EG) on the thermal properties of chlorinated paraffin (CP) and antimony trioxide (AT) on phase change material which bases on paraffin/high density polyethylene (HDPE) are studied. Differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), thermogravimetric analysis–Fourier transform infrared spectrometry (TGA–FTIR), microscale combustion calorimeter (MCC) and cone calorimeter (CONE) were used to evaluate the influence of EG on paraffin/HDPE/CP/AT system. The DSC results indicated that the latent heat value of PCM could be increased when the mass fraction of HDPE was decreased in the PCM, and EG could confine the molecular heat movement of paraffin. EG could improve the thermal stability and increase the char residue at high temperature for paraffin/HDPE/CP/AT hybrid. The volatilized products formed on thermal degradation of paraffin/HDPE/CP/AT with EG showed the release of CO2 gas was hastened and increased, and the amount of combustible gases were decreased by TGA–FTIR analysis. The MCC and CONE results presented that the flame retardant efficiency of CP/AT could be improved by adding EG in paraffin/HDPE/CP/AT system. [ABSTRACT FROM AUTHOR]

The two kinds of transition metal ion-incorporated nickel phosphates (TMIVSB-1) were synthesized by the hydrothermal method. The flame retardancy and thermal behavior of intumescent flame retardants (IFR), with and without TMIVSB-1 for PP, were investigated by LOI, UL-94 test, thermogravimetric analyses (TGA) and cone calorimetry. TMIVSB-1 can obviously improve the flame retardant behavior of IFR systems according to the results of LOI values and UL-94 test. The results of LOI show that 2 wt% TMIVSB-1 can increase the LOI value by 3-5 unit compared with that of PP/IFR composite. The UL-94 test shows that PP with 20% IFR burns and has no rating, but the addition of a small content 2 wt% of TMIVSB-1 with 18 wt% of IFR can reach a UL-94 V-0 rating. TGA results show that the thermal stability of PP/IFR/TMIVSB-1 increases obviously more than that of PP/IFR when the temperature is above 265°C. From cone calorimetry results, it can be observed that the HRR peaks are not obviously decreased, but the burning time of PP/IFR/FeVSB-1 (351s) and PP/IFR/ZnVSB-1 (380s) is obviously prolonged compared with that of PP/IFR (303s). The real time FTIR spectra (RTFTIR) demonstrates that the addition of TMIVSB-1 further staves the decomposition of the PP composites. The scanning electron microscopy (SEM) indicates the quality of char forming of PP/IFR/ TMIVSB-1 is superior to that of PP/IFR. [ABSTRACT FROM AUTHOR]

Abstract: An intumescent flame retardant spirocyclic pentaerythritol bisphosphorate disphosphoryl melamine (SPDPM) has been synthesized and its structure was characterized by Fourier transformed infrared spectrometry (FTIR), 1H and 31P nuclear magnetic resonances (NMR). A series of polylactide (PLA)-based flame retardant composites containing SPDPM were prepared by melt blending method. The combustion properties of PLA/SPDPM composites were evaluated through UL-94, limiting oxygen index (LOI) tests and microscale combustion calorimetry (MCC) experiments. It is found that SPDPM integrating acid, char and gas sources significantly improved the flame retardancy and anti-dripping performance of PLA. When 25wt% flame retardant was added, the composites achieved UL-94 V0, and the LOI value was increased to 38. Thermogravimetric analysis (TGA) showed that the weight loss rate of PLA was decreased by introduction of SPDPM. In addition, the thermal degradation process and possible flame retardant mechanism of PLA composites with SPDPM were analyzed by in situ FTIR. [Copyright &y& Elsevier]

A series of flame retardant hybrids were prepared based on bisphenol A polycarbonate (PC), trisilanolphenyl-polyhedral oligomeric silsesquioxane (TPOSS) and oligomeric bisphenyl A bis(diphenyl phosphate) (BDP) by melt blending method. The thermal stability and flame retardant properties of the hybrids were investigated by thermogravimetry analysis and cone calorimeter. Combination TPOSS with BDP in the appropriate ratio enhanced the thermal stability and the flame retardant properties of the PC matrix. The char residues of the hybrids were investigated by scan electronic microscopy (SEM) and X-ray photoelectron spectroscopy (XPS). The synergistic effect of BDP and TPOSS enhances the thermal stability and fire-resistance of the char layer which builds up on the surface of the burning polymer. [ABSTRACT FROM AUTHOR]

Abstract: Flame retardant polyurethane/organoclay nanocomposite based on polyether, organoclay, phenylmethane diisocyanate, diglycol, glycerine and flame retardant was synthesized. The morphology was characterized by X-ray diffraction and high-resolution electron microscopy. The mechanical properties, thermal stability, and flammability of flame retardant polyurethane/organoclay nanocomposite were investigated by tensile, thermogravimetry, and cone calorimetry experiments. It is shown that the flame retardant nanocomposite has enhanced tensile strength, capacity of carbonaceous char formation and flame retardant properties compared with pure polyurethane. The results show synergistic effects between organoclay, PU and flame retardant. [Copyright &y& Elsevier]

This work focused on investigating the pyrolysis characteristics of sorghum stalk (SS) and reed stalk (RS), whose potentiality as value-added feedstocks for thermochemical conversion is largely unexplored. The experimental method, thermogravimetric-infrared-mass spectrometry, was applied to reveal the thermal decomposition process, evaluate the kinetic and thermodynamic parameters, and identify the gaseous products, which could provide fundamental data and valuable information for bioenergy utilization and optimization of reactors. The average activation energy values of SS and RS by isoconversional methods are estimated to be 185.0–210.4 kJ/mol and 192.6–197.0 kJ/mol. Though kinetic parameters, especially activation energy values, play a crucial role in understanding reaction mechanism and guiding further applications, conventional methods are time-consuming and labor-intensive. In the current work, a gradient boosting regression tree model was successfully constructed to achieve fast prediction of activation energy values with a competitive accuracy of R2 > 0.85 without repetitive experiments. In addition, the established model has showed good generalization ability in new datasets, which reveals the great potential of the machine learning approach in the pyrolysis kinetic field. [Display omitted] • A detailed study on pyrolysis behavior of sorghum and reed stalk by TG/IR/MS. • Kinetic triplets and main gaseous products of biomass pyrolysis were reported. • Gradient boosting regression obtained the E α prediction performance of R2 > 0.85. • Partial dependency analysis provided insights into the ensemble algorithm. [ABSTRACT FROM AUTHOR]

Magnesium hydroxystannate [MgSn(OH)6, MgHS] was successfully prepared by a facile coprecipitation method. Then, MgHS was used to intumescent flame-retardant polypropylene systems. Thermogravimetry analysis results indicated that the introduction of MgHS can improve the thermal stability of the intumescent flame-retardant polypropylene system. Limiting oxygen index and UL-94 vertical burning test data show that the addition of MgHS can significantly improve the flame retardancy of intumescent flame-retardant polypropylene system. From the cone calorimetry results, it can be observed that the peak heat release rate is decreased in comparison with intumescent flame-retardant polypropylene. Moreover, the addition of MgHS significantly reduced the gaseous products, especially carbon monoxide. [ABSTRACT FROM AUTHOR]

Ferrous disulfide (FeS2) nanocrystals weresynthesizedvia a simple hydrothermal reaction. The FeS2nanocrystalswere then combined in intumescent flame-retardant ethylene–vinylacetate (EVA/IFR) systems. Thermogravimetric analysis data indicatethat the addition of FeS2into the EVA/IFR composite canimprove the char yields. Cone calorimeter results reveal that FeS2and IFR can clearly change the decomposition behavior ofEVA and form a char layer on the surface of the composites, consequentlyresulting in efficient reduction of the flammability parameters, suchas the heat release rate, total heat release, and so on. Moreover,significant improvements are obtained in the limited oxygen indexand Underwriters Laboratories 94 ratings. Laser Raman spectroscopyof residual char shows that the ordered carbon is increased with theaddition of FeS2. Scanning electron microscopy demonstratesthat FeS2can help the EVA/IFR system form a dense charlayer. The results of dynamic mechanical thermal analyses reveal thatFeS2can increase the glass transition temperature andthe storage modulus of EVA/IFR. The mechanism is also proposed inthis paper. [ABSTRACT FROM AUTHOR]

Ferric pyrophosphate (FePP) was used as additive to study its synergistic effect of thermal degradation on cotton fabrics. The microscale combustion calorimetry (MCC), thermogravimetric analysis (TG), Raman spectroscopy and Real Time Fourier transform infrared spectroscopy (RT-FTIR) were utilized to evaluate the synergistic effects of FePP on cotton/DIA. The MCC results revealed that cotton/DIA/FePP generated less combustion heat during heating than that of cotton/DIA. TG results showed that presence of FePP improved the thermal stability of materials. The Raman spectroscopy test showed that FePP can ameliorate the structural organization level of the carbon and the graphitization degree of the char. RT-FTIR data revealed the mechanism of the influence of FePP, which can catalyze the break of the flame retardant as well as promote the char forming. [ABSTRACT FROM AUTHOR]

Abstract: This paper presents a one-step preparation of novel nanocomposites consisting of a polymeric flame retardant (PDEPD) and clay. The clay was exfoliated or intercalated in the PDEPD according to X-ray diffraction (XRD) and transmission electron microscopy (TEM) studies. The PDEPD/clay nanocomposites were light-colored and highly water resistant. The initial decomposition temperature of the nanocomposites was higher than 200°C, meeting the processing temperature of many general polymer materials. The char formation of the nanocomposites was fairly high at 700°C, ranging from 43.3% to 53.5%. When the PDEPD/clay nanocomposites were incorporated into polystyrene (PS) and polyurethane (PU) matrix, the flame retardancy of the composites was evidently improved. The TEM images showed that the clay layers were almost exfoliated in PS matrix and mainly intercalative in PU matrix. The PDEPD/clay nanocomposites can be used as novel halogen-free flame retardant agents in many general polymer materials. [Copyright &y& Elsevier]

The intumescent flame retardant polylactide/polyhedral oligomeric silsesquioxane (IFR-PLA/POSS) composites were prepared via a melt blending method. The morphology of the PLA nanocomposites was assessed by transmission electron microscopy (TEM). Dynamic mechanical analysis (DMA) and tensile tests showed that the incorporation of POSS enhanced the mechanical properties of the PLA matrix. The limiting oxygen index (LOI) values increased from 20.0% for neat PLA to 40.0% for PLA based on 22.5 wt% IFR and 7.5 wt% POSS, and the latter could pass UL-94 V0 rating. Thermal gravimetric analysis (TGA) showed that the thermal stability of the residual char at the later stages of the thermal degradation was significantly improved. The dynamic Fourier transform infrared (FTIR) spectra suggested that the thermally stable poly(phosphoricacid) and polysiloxane derivatives were formed during the thermal degradation process of PLA/POSS composite. The scanning electron microscope (SEM) and X-ray photoelectron spectrography (XPS) indicated that the residual char of flame retardant PLA/POSS composite had a exterior layer with a compact and continual surface, while the interior had a porous structure, which was composed of cross-linked phosphorous oxynitride and carbonized aromatic networks. [ABSTRACT FROM PUBLISHER]

Abstract: This work mainly deals with a novel flame retardant system for glass-fiber reinforced poly(1,4-butylene terephthalate) (GRPBT) composites using trivalent rare earth hypophosphite (REHP) and melamine cyanurate (MC) through melt blending method. Firstly, two types of REHP, lanthanum hypophosphite and cerium hypophosphite, were synthesized and characterized. Thermal gravimetric analysis (TGA) was employed to investigate the thermal decomposition behavior of REHP and flame retardant treated GRPBT composites. Thermal combustion properties were measured using microscale combustion calorimeter. Fire performance was evaluated by limiting oxygen index, Underwriters Laboratories 94 and cone calorimeter. The results showed that the flammability of GRPBT is significantly reduced by the incorporation of the flame retardant mixture. Mechanism analysis revealed that the addition of MC reduces the condensed phase effect of REHP, but improves the flame inhibition in gas phase. [Copyright &y& Elsevier]

Abstract: A novel phosphorus-containing oligomeric flame retardant, poly(DOPO substituted hydroxyphenyl methanol pentaerythritol diphosphonate) (PDPDP) was synthesized and applied to flame retarded epoxy resins. The thermal degradation behaviors of flame retarded epoxy composites with PDPDP were investigated by thermogravimetric analysis (TGA), thermogravimetric analysis/infrared spectrometry (TG-FTIR) and direct pyrolysis-mass spectrometry (DP-MS) techniques. The identification of pyrolysis fragment ions provided insight into the flame retardant mechanism. The results showed that the mass loss rate of the EP/PDPDP composites was clearly lower than pure EP when the temperature was higher than 300°C in air or nitrogen atmosphere. The results also suggested that the main decomposition fragment ions of the EP/PDPDP composite were H2O, CO2, CO, benzene, and phenol. The incorporation of PDPDP can reduce the release of combustible gas and induce the formation of char layer, hence the fire potential hazard was reduced. [Copyright &y& Elsevier]

Starting from expandable graphite (EG), graphene, graphite oxide (GO), and organic phosphate functionalized graphite oxides (FGO) were prepared and incorporated into epoxy resin (EP) matrix via in situ polymerization to prepare EP based composites. The structure of the composites was characterized by transmission electron microscopy to show good dispersion without large aggregates. The thermal behavior investigated by thermogravimetric analysis indicated the EP/graphene composites show the highest onset temperature and maximum weight loss temperature compared with those added with GO and FGO. The flame retardant properties investigated by micro combustion calorimeter illustrate that both EP/graphene and EP/FGO composites perform better than EP/GO composites in flame retardant properties with a maximum reduction of 23.7% in peak-heat release rate when containing 5 wt % FGO and a maximum reduction of 43.9% at 5 wt % loading of graphene. This study represents a new approach to prepare functionalized GO with flame retardant elements to improve the flame retardancy of polymer and gives a way of application of graphene in enhancing thermal stabilities of polymer. [ABSTRACT FROM AUTHOR]

UV-curable waterborne polyurethane acrylate (WPUA) modified with octavinyl polyhedral oligomeric silsesquioxane (OVPOSS) was prepared via photopolymerization between OVPOSS and WPUA. Structural and morphological features of WPUA/OVPOSS coatings were assessed using Fourier transform infrared spectroscopy, transmission electron microscopy and X-ray diffraction. Thermal properties of the WPUA/OVPOSS hybride coatings have been improved over the pure waterborne polyurethane acrylate analyzed by thermal gravimetric analysis. Performance of the coatings was also evaluated using water absorption, hardness, contact angle, X-ray photoelectron spectroscopy (XPS). The data showed that the WPUA/OVPOSS coatings possessed better water resistance and thermal oxidative stability in comparison with pure WPUA. [ABSTRACT FROM AUTHOR]

Abstract: Advanced flame retardant epoxy resins with different contents of poly(DOPO substituted phenyl dimethanol pentaerythritol diphosphonate) (PFR) were prepared. PFR was synthesized from the polycondensation of DOPO-disubstituted benzenedimethanol (TDCA-DOPO) with pentaerythritol diphosphonate dichloride (SPDPC). The flame retardancy and thermal stability of the EP/PFR hybrids were investigated by limiting oxygen index (LOI), UL-94 test and thermogravimetric analysis (TGA) in air. LOI values increased from 21.5 for pure EP to 36.0 for phosphorus-containing resins, and UL-94 V-0 materials were obtained with the 15wt% PFR. The TGA results indicated that incorporation of PFR significantly enhanced the char yield and the thermal stability of char layer at higher temperature. Differential scanning calorimetry revealed that the EP/PFR composites possessed higher glass transition temperatures than phosphorus-free EP, which was consistent with dynamic mechanical analysis results. The thermal degradation behaviors of the EP/PFR composites were investigated by real time Fourier transform infrared spectra (RTFTIR), thermogravimetric analysis/infrared spectrometry (TG–IR) and direct pyrolysis/mass (DP–MS) analysis. The results suggested that the addition of PFR can reduce the release of combustible gas, trap the H and OH radicals by releasing the PO radical and induce the formation of char layer, thus retard the polymer degradation and combustion process. [Copyright &y& Elsevier]

Phosphorus-modified siloxanes monomer DOPO-IPDI-AMEO (DIA) was synthesized and characterized by H nuclear magnetic resonance (H NMR), P NMR, and Fourier transform infrared spectra (FTIR). It hydrolyzed and grew an organic-inorganic hybrid coating on the surface of cotton fabrics via sol-gel process. The conversion of gel reaction was characterized by solid-state Si NMR. The effect of the modified organic-inorganic hybrid materials on thermal properties of cotton fabrics was investigated by thermogravimetric (TG) analysis, real time Fourier transform infrared (RT-FTIR), and microscale combustion calorimetry (MCC) experiments. In addition, thermogravimetry-Fourier transform infrared spectra (TG-FTIR) were used to investigate the released degradation products. The characterization information represented that DIA has been prepared successfully. Also the conversion of gel reaction was fairly high. The TG data showed that char residues increased with the addition of the DIA coating. While the peak heat release rate (PHRR) decreased with the presence of the coating in MCC test. Moreover, the flammable degradation products dropped obviously, which can be observed from the data of TG-FTIR. [ABSTRACT FROM AUTHOR]

Abstract: In this paper, we report one novel kind of organic–inorganic mesoporous hybrid from octa-anionic polyhedral oligomeric silsesquioxanes (POSS) and cationic surfactant. The mesoporous hybrid was achieved by two steps: first, lamellar precursor made of POSS and surfactant was prepared by template-directed synthesis; then mesoporous structure was obtained via the reformation of lamellar precursor under hydrothermal treatment. According to our experimental results (XRD, TEM and SEM), the lamellar-to-hexagonal mesophase transformation process and its mechanism was suggested. The thermal stability and degradation behavior of the mesoporous hybrid was also discussed based on TGA curves obtained under nitrogen atmosphere. [Copyright &y& Elsevier]

Abstract: The catalyzing carbonization function of alpha-zirconium phosphate (α-Zr(HPO4)2·H2O, α-ZrP) based on an intumescent fire retardant (IFR) polypropylene (PP) system is reported. The IFR system consists of ammonium polyphosphate and pentaerythritol. The morphology of the PP/organophilic ZrP nanocomposites is characterized by X-ray diffraction and high resolution transmission electron microscopy (HRTEM). The results indicate that an intercalated structure is formed. Thermogravimetric analysis, limiting oxygen index (LOI) and UL-94 are used to characterize the thermal stability and the flame retardant properties. It is found that there is a transformation of the char microstructure and an increment of LOI value in the PP systems with the OZrP, and the UL-94 level is improved, from failure, to a V-0 rating. The synergistic effect improves the flame retardant properties of PP remarkably. The morphology and structure (HRTEM and selected area electron diffraction) of the char residue also indicate the presence of graphite sheets. A possible mechanism for catalyzing carbonization is discussed. [Copyright &y& Elsevier]

We investigated the thermal decomposition behaviors of two typical grains, rice and corn, using a thermogravimetric analyzer at different heating rates. The pyrolysis process of rice and corn both can be divided into three stages, and the most possible pyrolysis mechanism of both rice and corn during devolatilization is a three-dimensional diffusion reaction, which can be represented by the Zhuravlev equation (G(α) = [(1 − α)(−1/3) − 1]2). Corn had a higher initial degradation temperature and end temperature as well as a higher mass loss in the second stage than rice. The average Ea of rice determined by Kissinger, FWO and Friedman method was 143.6 kJ mol−1, 161.6 kJ mol−1 and 148.7 kJ mol−1, respectively. The average Ea of corn determined by Kissinger, FWO and Friedman method was 166.1 kJ mol−1, 146.3 kJ mol−1 and 170.4 kJ mol−1, respectively. A lower Ea of rice than corn also indicates that rice is easier to be pyrolyzed. The predicted values using the kinetic parameters calculated show a good agreement with the experimental data at all the four heating rates. The results presented herein could provide guidance for storage of grains. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • A hybrid coating was developed via few bi-layers deposition and sol-gel process. • This coating improved the flame retardant and hydrophilic properties of PA66 fabrics. • A 30% reduction in pHRR was realized for B-doped silica sol treated fabric. • B-doped silica sol showed superior properties over only silica sol treated fabric. • Sol-gel treatment could stabilize the LbL assembled coatings in laundering. Abstract A hybrid methodology, including a few layer deposition of bio-based polyelectrolytes, chitosan (CS) and phytic acid (PA), along with a sol-gel treatment from (3-Aminopropyl) triethoxysilane (APTES) and boron doped APTES sol solutions, was followed in constructing a flame retardant and hydrophilic coating onto polyamide 66 (PA66) fabric surfaces. Layer by layer (LbL) assembled and simultaneously sol-gel treated PA66 fabric samples (i.e., PA66-5BL-APTES and PA66-5BL-B-d-APTES) could be able to stop the melt-dripping in vertical burning test. The boron doped APTES sol treated fabric samples with a 2–5 bi-layers deposition showed a reduced peak heat release rate (pHRR) (i.e., 22–30 % reduction) in cone calorimetry test and revealed improved thermal stability in thermogravimetric analysis test. More interestingly, the boron doped silica sol could boost up the hydrophilicity of the treated fabrics significantly compared to only LbL and simultaneously LbL deposited and silica sol treated fabric samples. Furthermore, only the 5 bi-layers deposited and concurrently sol-gel treated fabric samples exhibited durable flame retardant behavior after laundering. [ABSTRACT FROM AUTHOR]

Highlights • The cotton fabrics were treated with genipin crosslinked (PEI/HACH) n coating. • C-(PEI/HACH)10-crosslink extinguished the fire in horizontal burning test. • The PHRR and THR of C-(PEI/HACH)10 were reduced significantly. • The genipin crosslinked (PEI/HACH) n coating exhibited good wash durability. Abstract A crosslinked and flame retardant coating was fabricated by layer-by-layer self-assembly on cotton fabric. The coated fabric was treated using positively charged polyethylenimine (PEI) and negatively charged hypophosphorous acid-modified chitosan (HACH) with subsequent crosslinking with genipin. The thermal stability and flammability of the treated cotton fabric were investigated by thermogravimetric analysis (TGA), the horizontal flame test and microscale combustion calorimetry. TGA results showed that, in an air atmosphere, there was more char residue for the treated cotton fabrics than for the untreated cotton fabric. The cottons treated with a 10-bilayer coating (C-(PEI/HACH)10 and C-(PEI/HACH)10-crosslink) could extinguish the fire during the horizontal burning test. The peak heat release rate and total heat release rate of C-(PEI/HACH)10 were reduced by 73% and 80%, respectively, compared with those of the untreated one. At the same time, the genipin crosslinked PEI/HACH coating exhibited good wash durability and mechanical properites for the treated fabrics. [ABSTRACT FROM AUTHOR]

Flame retardant rigid polyurethane foam (RPUF) with a reactive melamine-derived polyol (MADP) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) were fabricated through free-rise technique. The thermal stability and fire behaviors of RPUF were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), and cone calorimeter. In comparison with the results of RPUF and RPUF/MADP, RPUF/MADP-DOPO displayed higher compressive strength, owing to the two stiff phenyl groups of DOPO. Moreover, with only 7.5 wt % MADP and 7.5 wt % DOPO loading, the MADP/DOPO system endowed RPUF with enhanced char formation, increased LOI value of 28.5% and reduced heat release. Scanning electron microscope (SEM) images, X-ray photoelectron spectroscopy (XPS) analysis and Raman spectra of the char residues suggested that the formation of compact, continuous char layer. The thermal degradation was characterized using thermogravimetric analysis/infrared spectrometry (TG-IR) and chemical structure changes during the thermal degradation were monitored by real time Fourier transform infrared (RT-FTIR), these results demonstrated that the partial phosphorus from DOPO remained in the residual char, but the introduction of MADP significantly promoted generating more stable aromatic structure and enhanced the strength of the char layer formed. Furthermore, MADP facilitated the formation of more H 2 O and CO 2 and diluted the flammable gases in gaseous phase. Based on the analysis, the introduction of MADP/DOPO can endowed excellent flame retardancy to RPUF depending on bi-phase flame-retardant mechanism. [ABSTRACT FROM AUTHOR]

A novel mono-component intumescent flame retardant, named as hyper-branched triazine-piperazine pyrophosphate (HTPPP), is synthesized by using cyanuric chloride, 1-boc-piperazine and phosphoric acid. Chemical structures of HTPPP are characterized by fourier transform infrared (FTIR) spectra, 31 P nuclear magnetic resonance (NMR), solid-state 13 C NMR, elemental analysis (EA) and inductively coupled plasma mass spectrometer (ICP-MS). The resulting HTPPP is used alone as an intumescent flame retardant for polypropylene (PP). PP/HTPPP composite can achieve a limiting oxygen index (LOI) value of 30.5% and the vertical burning test (UL-94) V-0 rating at 25 wt% HTPPP loading. Besides, HTPPP is thermally stable with initial decompose temperature as high as 275 °C in air atmosphere. The flame retardant mechanism is concluded based on the analysis of the char residue. [ABSTRACT FROM AUTHOR]

A well-defined functionalized graphene oxide (FGO) grafted by hyper-branched flame retardant based on N -aminoethyl piperazine and phosphonate derivative was synthesized to reduce flammability and toxicity of polystyrene (PS). The chemical structure, morphological and thermal properties were characterized by Fourier transform infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, transmission electron microscopy and thermogravimetric analysis, respectively. Micro combustion calorimeter and steady state tube furnace were employed to evaluate the heat and non-heat fire hazards of PS nanocomposites. The incorporation of FGO into PS matrix effectively improved the flame retardancy and restrained the toxicity of the volatiles escaped, which is attributed to that the homogeneous dispersion of FGO in the PS matrix enhanced barrier effect that reduced peak heat release rate, total heat release and toxic gas release during combustion. Furthermore, PS-FGO nanocompsites obviously decreased the amount of flammable and toxic volatiles evolved, such as the aromatic compounds, carbonyl compounds, carbon monoxide, indicating suppressed fire hazards of the PS composites. [ABSTRACT FROM AUTHOR]

The self-extinguishing coating, consisting of biobased chitin derivatives, phosphorylated chitin and deacetylated chitin (chitosan), was deposited on cotton fabrics via the Layer-by-Layer (LbL) assembled method. The content of phosphorylated chitin prepared on cotton fabrics surface is dependent on the bilayers’ number and concentration of phosphorylated chitin. In the vertical flame test, the cotton fabric with 20 bilayers prepared at the high phosphorylated chitin concentration (2 wt%) could extinguish the flame. Microcombustion calorimetry result showed that all coated cotton fabrics showed lower peak heat-release rate and total heat-release values compared with that of the pure one. Thermogravimetric analysis result indicated that thermal and thermal oxidation stability of all coated cotton fabrics were enhanced in the high temperature range (400–700 °C). This work provided the flame retardant multilayer films based on fully biobased chitin derivatives on cotton fabrics to enhance its flame retardancy. [ABSTRACT FROM AUTHOR]

A novel hyperbranched charring foaming agent (HCFA), successfully prepared via an A 2 B 3 approach with about 97% yield, was combined with ammonium polyphosphate (APP) to flame-retard polypropylene (PP) at a 30 wt% loading. The results of thermogravimetric analyses of various PP samples in air and nitrogen showed that the HCFA/APP system could effectively improve the thermal and thermal-oxidative stabilities of the char residues. And PP3 with a 3/1 mass ratio of APP to HCFA left the highest amount of char residue at 800 °C. The studies of their flammability revealed that the addition of HCFA can make great contribution to the increase of the limiting oxygen index and the UL-94 V0 rating, and the decrease of the heat release rate (HRR) and fire growth index (FGI) of PP/APP/HCFA composites relative to PP with 30 wt% APP. The investigation of their water resistance demonstrated that the PP composites with a mass ratio of APP to HCFA being between 3:1 and 1:1 still obtained a UL-94 V-0 rating after 168 h soaking in hot water, due to the delayed migration of intumescent flame retardant from the complexation between hydrophilic APP and hydrophobic HCFA. Besides, their mechanical properties were also investigated. [ABSTRACT FROM AUTHOR]

Abstract: Ethylene-vinyl acetate copolymer (EVA) flame retarded by a combination of cellulose acetate butyrate (CAB) microencapsulated ammonium polyphosphate (MCAPP) and polyamide-6 (PA-6) have been crosslinked by high energy electron beam irradiation. The effect of high energy electron beam irradiation on the crosslinking degree, mechanical, electrical and thermal properties of EVA/MCAPP/PA-6 cable material was studied by gel content, heat extention test, mechanical test, dynamic mechanical analysis, high-insulation resistance meter and thermogravimetric analysis. The gel content and heat extention test results showed that the EVA/MCAPP/PA-6 composites can be easily crosslinked by electron beam irradiation. The tensile strength of EVA composites was drastically increased from 16.2 to maximum 26.2MPa as the electron beam irradiation dose increases from 0 to 160kGy. The volatilized products of EVA/MCAPP/PA-6 composites were analyzed and compared by thermogravimetric analysis/infrared spectrometry (TG-FTIR). [Copyright &y& Elsevier]

In this work, two kinds of rare earthhypophosphites (REHP), lanthanum hypophosphite (LaHP) and cerium hypophosphite(CeHP), were synthesized and characterized. Subsequently, LaHP andCeHP were added into polylactide to improve its flame retardant properties.Thermal gravimetric analysis was employed to investigate the thermaldecomposition behavior of REHP and flame retardant polylactide composites(FR-PLA). The fire performance evaluated by microscale combustioncalorimetry and cone calorimeter clearly demonstrated that the additionof LaHP and CeHP resulted in significant reduction of the heat releaserate, low total heat release, and compact intumescent char layer.Thermogravimetric analysis–infrared spectrometry testing indicatedthat the addition of REHP significantly decreased the yields of pyrolysisproducts. Furthermore, the crystallization behaviors of FR-PLA compositeswere investigated by differential scanning calorimetry. The char residueof FR-PLA composites after cone calorimeter testing were also be investigatedby scanning electron microscope, Fourier transform infrared spectroscopy,and X-ray photoelectron spectroscopy. [ABSTRACT FROM AUTHOR]

A series of flame retarding biodegradable polylactic acid composites (FR-PLA) based on aluminum hypophosphite (AHP) and expanded graphite (EG) were prepared by the melt-compounding method. The effect of AHP and EG on the flame retardancy and thermal stability of PLA were investigated by thermogravimetric analysis (TGA), UL-94 vertical burning test, limiting oxygen index, microscale combustion calorimetry and cone calorimeter testing. The gas products of PLA and FR-PLA composites were investigated by TG-IR technology. TGA results showed that the FR-PLA composites presented higher char residue and reduced mass loss rate than neat PLA. Significant improvement of flame retardancy of PLA/AHP/EG composites indicated an excellent synergistic effect between AHP and EG. Cone calorimeter tests gave clear evidence that the combination of AHP and EG resulted in a significant reduction of the heat release rate (HRR) and total heat release (THR). TG-IR revealed that the combination of AHP and EG resulted in significant decrease of gas products. The char residue of FR-PLA composites were also investigated by scanning electron microscope, Fourier transform infrared spectra spectroscopy and X-ray photoelectron spectroscopy. Based on the analysis, possible flame retardant mechanism was discussed. [ABSTRACT FROM PUBLISHER]

Abstract: In this work, multi-layer graphene has been prepared by pyrolyzing poly(methyl methacrylate) (PMMA) on nickel microparticles in the confined microzones formed by organophilic montmorillonite (OMT). Gram-scale of product can be obtained per day by using this method. The obtained graphene was evaluated by scanning and transmission electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, Fourier transform infrared spectroscopy and thermogravimetric analysis. Pyrolytic conditions such as the system composition of the composites, reaction temperature and the size of catalyst are important parameters affecting the morphology and yield of the final product. Based on the experimental observations and reported literatures, a possible formation process is discussed. The synthesis method of graphene is simple, low-cost, and scalable, which is promising for the application in many fields. [Copyright &y& Elsevier]

Abstract: The ultrafine composite fibers based on the composites of binary fatty acid eutectics and polyethylene terephthalate (PET) with varied fatty acid eutectics/PET mass ratios (50/100, 70/100, 100/100 and 120/100) were fabricated using the technique of electrospinning as form-stable phase change materials (PCMs). The five binary fatty acid eutectics including LA–MA, LA–PA, MA–PA, MA–SA and PA–SA were prepared according to Schrader equation, and then were selected as an innovative type of solid–liquid PCMs. The results characterized by differential scanning calorimeter (DSC) indicated that the prepared binary fatty acid eutectics with low phase transition temperatures and high heat enthalpies for climatic requirements were more suitable for applications in building energy storage. The structural morphologies, thermal energy storage and thermal stability properties of the ultrafine composite fibers were investigated by scanning electron microscope (SEM), DSC and thermogravimetric analysis (TGA), respectively. SEM images revealed that the electrospun binary fatty acid eutectics/PET ultrafine composite fibers possessed the wrinkled surfaces morphologies compared with the neat PET fibers with cylindrical shape and smooth surfaces; the grooves or ridges on the corrugated surface of the ultrafine composite fibers became more and more prominent with increasing fatty acid eutectics amount in the composite fibers. The fibers with the low mass ratio maintained good structural morphologies while the quality became worse when the mass ratio is too high (more than 100/100). DSC measurements suggested that the heat enthalpies of melting and crystallization of the ultrafine composite fibers increased gradually with increasing fatty acid eutectics amounts, but their phase transition temperatures had almost no obvious variation as relative to the corresponding fatty acid eutectics. Meanwhile, the characteristic temperatures and heat enthalpies of the ultrafine composite fibers varied with the different types of binary fatty acid eutectics. TGA results indicated that the degradation of electrospun binary fatty acid eutectics/PET ultrafine composite fibers with representative mass ratio of 100/100 had two steps and corresponded respectively to the degradations of binary fatty acid eutectics and PET polymer chains; and the charred residue at 700°C of the composite fibers was lower than that of the neat PET fibers. It could be envisioned that the electrospun binary fatty acid eutectics/PET composite fibers would be extensively used for latent heat storage in the field of building energy conservation. [Copyright &y& Elsevier]

Two kinds of novel phosphorus-containing polyether toughening agents were synthesized and characterized by H nuclear magnetic resonance (H NMR) and Fourier transform infrared spectra (FTIR). Afterwards, a series of phenolic foams with different loadings of phosphorus-containing toughening agents were prepared. The apparent density and scanning electron microscopy (SEM) results showed that the addition of 5 wt% toughening agents increased the expansion ratio and promoted the formation of uniform cells. The limiting oxygen index (LOI) values of modified phenolic foams decreased with the increase of modifier content, but it still remained at 40% even if the amount of modifier loadings was 10 wt%. UL-94 results showed all samples can pass V0 rating, indicating the modified foams still have great flame retardance. Microscale combustion calorimetry (MCC) results indicated that the peak heat release rate (PHRR) and total heat release (THR) of the modified foams were reduced by 42% and 35%, respectively, compared to the pure phenolic foams. Moreover, the thermal stability of samples was investigated by thermogravimetric analysis (TGA). The mechanical properties were evaluated and correlated with composition and structural features. [ABSTRACT FROM AUTHOR]

Abstract: Nanocomposites of poly(vinyl alcohol) with α-type zirconium phosphate (PVA/ZrP) and with layered silicates (montmorillonite and hectorite) were prepared by solution blending. Thermal properties and flame retardancy of the materials were characterized by thermogravimetric analysis and microscale combustion calorimetry. PVA/ZrP nanocomposite showed a faster charring process in temperature range between 200 and 350 °C but higher thermal stability and greater char yields above 350 °C and a different heat release rate feature, compared to clay-based samples. Observation of the micrographs of the chars from the nanocomposites present two distinct structures; one constituted by the stacked clay layers on the surface combined with clay-reinforced foams in the interior residue, and the other formed by carbon covered on the tightly curled ZrP nanoplatelets. The results indicated different flame retardant mechanisms of the two nanocomposites, which depend on the chemical/physical effects from the inherent properties of the nanofillers. [Copyright &y& Elsevier]