Search

In this article, melamine (MA) and melamine phosphate (MP) have been intercalated into α-type zirconium phosphate (α-ZrP) interlayer spaces. The structure and thermal properties of the corresponding powders, MA-ZrP and MP-ZrP, were ascertained by X-ray diffraction, Fourier transform infrared spectra, X-ray photoelectron spectroscopy measurement, and thermogravimetric analyses (TGA). Furthermore, polypropylene (PP) and its intumescent flame retardant (IFR) composites containing the two organically modified α-ZrP powders using maleic anhydride-grafted PP (JPP) as compatibilizer were fabricated by melt blending. The results from TGA and cone calorimetry demonstrated that PP/JPP and PP/JPP/IFR composites containing MA-ZrP and MP-ZrP exhibited better thermal stability and burning behavior in comparison with their corresponding counterparts, PP/JPP and PP/JPP/IFR, respectively. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40254. [ABSTRACT FROM AUTHOR]

In present work, silica pillared montmorillonite material (C-SiO2-OMT) was prepared via the sol-gel method, and the influence of the powder on thermal stability and flammability performance of polypropylene (PP) composites was investigated. Characterization of C-SiO2-OMT, elucidated with X-ray diffraction, transmission electron microscopy, and N2 adsorption-desorption, suggested that the powder had a mesoporous lamellar structure with high specific surface area and mesoporous volume. The formation of porous structure of C-SiO2-OMT was more conducive than organically modified montmorillonite (OMT) to slowing the volatilization of pyrolytic products generated during thermal degradation process, which led to PP/C-SiO2-OMT microcomposite show better thermal stability than PP/OMT nanocomposite at high temperature range. Flammability properties of these polymer materials evaluated by microscale combustion calorimetry, and cone calorimetry showed a contrary tendency, but C-SiO2-OMT holds high promise to reduce the smoke yield. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A 1D copper(II) complex [Cu(Hbtc)(PyBIm)2]n(H3btc=1,3,5-benzenetricarboxylic acid, PyBIm=2-(4-pyridyl)benzimidazole) has been synthesized and characterized by elemental analysis, IR, and single-crystal X-ray diffraction. A crystallographically independent copper(II) atom is coordinated by three oxygen and two nitrogen donors in a five-coordinate distorted square pyramid geometry ([CuN2O3]). Two copper coordination units ([CuN2O3]) are linked togetherviatwo carboxyl groups of two Hbtc2−ligands, forming a dimetal unit ([CuN2O3]2). The tridentate Hbtc2−anion, as bridging ligand, connects the dimetal units into 1D chain-like structure. Supplemental materials are available for this article. Go to the publisher's online edition orSynthesis and Reactivity in Inorganic, Metal-Organic, and Nano-Metal Chemistryto view the supplemental file. [ABSTRACT FROM PUBLISHER]

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]

Phosphorus/nitrogen-containing advanced epoxy resins were obtained by chain-extension of the diglycidyl ether of bisphenol-A epoxy (DGEBA) resin with phosphorus-modified triglycidyl isocyanurate (TGICP). The structure of TGICP was characterized by Fourier transform infrared spectroscopy (FTIR) and nuclear magnetic resonance (NMR). Differential scanning calorimetry revealed that the EP/TGICP composites possessed higher glass transition temperatures than that of phosphorus free EP. The thermal stability and flame retardant properties of the epoxy resin/TGICP systems were investigated by thermogravimetric analysis (TGA), limiting oxygen index (LOI), and vertical burning test (UL-94) test. When the TGICP content was 10 wt%, the LOI value of epoxy resin system was as high as 35.0% and it can obtain the V-0 grade in UL-94 protocol. From microscale combustion calorimetry (MCC) measurement, it was found that the addition of TGICP reduced the value of peak heat release rate and total heat release. The thermal degradation process of EP and EP/TGICP composite was monitored by real time FTIR. Moreover, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to explore the morphology and chemical components of the char residues. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

A phosphorus- and nitrogen-containing compound (2-dimethylamino ethyl phenyl hydroxyethyl acrylate phosphate) and its oligomer (poly(2-dimethylamino ethyl phenyl hydroxyethyl acrylate phosphate), PDPHP) were synthesized and characterized. The polystyrene (PS) composites with various amounts of PDPHP were prepared by melt blending. The thermal stability of the PDPHP and PS composites was investigated by thermogravimetric analysis. The flame retardancy of the composites was evaluated using microscale combustion calorimeter and limiting oxygen index test. A Fourier transform infrared (FTIR) spectroscopy coupled with a thermogravimetric analyzer was also used to study the gas phase from the degradation of PS composites. The char residues of the PS composites containing 30 wt % PDPHP were analyzed by FTIR and scanning electron microscopy. The results suggest that the incorporation of PDPHP into PS can evidently enhance the char formation and improve the flame retardancy of virgin PS. The compact and coherent char formed during degradation was attributed to the enhancement of char quality and flame retardance. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011 [ABSTRACT FROM AUTHOR]

A triazine ring-containing charring agent (PEPATA) was synthesized via the reaction between 2,6,7-trioxa-l-phosphabicyclo-[2.2.2]octane-4-methanol (PEPA) and cyanuric chloride. It was applied into intumescent flame retardant epoxy resins (IFR-EP) as a charring agent. The effect of PEPATA on fire retardancy and thermal degradation behavior of IFR-EP system was investigated by limited oxygen index (LOI), UL-94 test, microscale combustion calorimetry (MCC), thermogravimetric analysis (TGA) and thermogravimetric analysis/infrared spectrometry (TG-IR). The glass transition temperatures ( Tg) of IFR-EP systems were studied by dynamic mechanical analysis (DMA). The LOI values increased from 21.5 for neat epoxy resins (EPs) to 34.0 for IFR-EP, demonstrating improved flame retardancy. The TGA curves showed that the amount of residue of IFR-EP system was largely increased compared to that of neat EP at 700 °C. The new IFR-EP system could apparently reduce the amount of decomposing products at higher temperatures and promotes the formation of carbonaceous charred layers that slowed down the degradation. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

In this paper, the effect of organo-modified montmorillonite (OMMT) on a novel intumescent flame retardant (IFR) system was studied in poly(1,4-butylene terephthalate) (PBT) composites containing microencapsulated ammonium polyphosphate (MAPP) and melamine cyanurate (MC). Nanocomposite morphology was characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Thermal decomposition analysis was studied via thermogravimetric analysis (TGA). Combustion behavior was investigated by microcombustion calorimeter (MCC), limited oxygen index (LOI), and UL-94 test. Residues obtained after samples treated in muffle furnace at 500°C under air condition for 10 min were analyzed through X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). It was found that the addition of OMMT improved the flame retardancy of PBT/IFR composites significantly. A mass of microcomposite structure particles formed in the heating or combustion process of PBT/IFR/OMMT nanocomposites were found for the first time in the SEM images, which is strong evidence to confirm the migration or accumulation of montmorillonite and carbonaceous-silicate materials during the heating or combustion process. Copyright © 2010 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Abstract: Brominated flame retardant polystyrene composites were prepared by melt blending polystyrene, decabromodiphenyl oxide, antimony oxide, multi-wall carbon nanotubes and montmorillonite clay. Synergy between carbon nanotubes and clay and the brominated fire retardant was studied by thermogravimetric analysis, microscale combustion calorimetry and cone calorimetry. Nanotubes are more efficient than clay in improving the flame retardancy of the materials and promoting carbonization in the polystyrene matrix. Comparison of the results from the microscale combustion calorimeter and the cone calorimeter indicate that the rate of change of the peak heat release rate reduction in the microscale combustion calorimeter was slower than that in the cone. Both heat release capacity and reduction in the peak heat release rate in the microscale combustion calorimeter are important for screening the flame retardant materials; they show good correlations with the cone parameters, peak heat release rate and total heat released. [Copyright &y& Elsevier]

The performances of the novel intumescent flame retardant (IFR) polypropylene (PP) composites containing melamine phosphate (MP) and tris(1-oxo-2,6,7-trioxa-1-phosphabicyclo[2,2,2]methylene-4)phosphate (TPMP) were investigated. The flame retardancy of IFR-PP system was characterized by limiting oxygen index (LOI) and UL 94 and cone calorimeter. The morphology of the char obtained after cone calorimeter testing was studied by scanning electron microscopy (SEM). The thermal oxidative degradation (TOD) of the composites was investigated by using thermogravimetric analysis (TGA) and real-time Fourier transform infrared spectroscopy (RT-FTIR). Compared with the PP/ TPMP or PP/ MP binary composite, at the same addition level, the LOI values of the PP/MP/TPMP ternary composites increase and reach V-0 at the suitable MP/TPMP ratio. The results of TGA and RT-FTIR showed the existence of the interaction between IFR and PP. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]

Microencapsulated ammonium polyphosphate with polyurethane resin (PUMAPP) was prepared by in situ polymerization and characterized by X-ray photoelectron spectroscopy (XPS). The flame retardation of PUMAPP/dipentaerythritol(DPER) and ammonium polyphosphate (APP)/DPER flame retarded polypropylene (PP)/ethylene propylene diene rubber (EPDM) composites were studied using limiting oxygen index (LOI), UL-94 test and cone calorimeter. Results demonstrated that the flame retardancy of the PP/EPDM/PUMAPP/DPER composites was better than that of the PP/EPDM/APP/DPER composites at the same additive loading. Real time Fourier transform infrared (FTIR) and thermogravimetric analysis (TG) were used to study the thermal degradation and stability of the PP/EPDM/PUMAPP/DPER composite. The hydrolytic stability of the flame retarded PP/EPDM composites was studied. It was found that the microencapsulation of APP with the PU resin leaded to a decrease in the particle's water solubility. Moreover, the synergistic effect of vinyltrimethoxysilane (VTMS) on the PP/EPDM/PUMAPP/DPER composite was also investigated. [ABSTRACT FROM AUTHOR]

Abstract: In this letter, graphene oxide (GO) was prepared by a kind of modified Hummers' method, which via ultrasonic treatment could be dispersed in water to obtain a homogeneous and stable brownish yellow flocculent solution. AgBr/Ag/Ag2O/GO nanocomposite catalyst was produced by adding hexadecyltrimethyl ammonium bromide (CTAB) and silver nitrate solution into the above formed GO solution under ultrasonic treatment. The structures, morphologies, and light absorption properties of AgBr/Ag/Ag2O/GO composite catalysts were characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and ultraviolet and visible diffuse reflectance spectroscopy (UV-DRS). Preliminary results showed that the composite catalyst has a better catalytic degradation effect on organic dyes like rhodamine B (RhB) and methyl orange (MO) in polluted water under simulated solar light irradiation in contrast to the single GO and AgBr. [Copyright &y& Elsevier]