A novel phosphorus-containing monomer, (6-oxido-6H-dibenzo[c,e][1,2]oxaphosphinin-6-yl)methyl acrylate (DOPO-AA), is first synthesized and characterized by Fourier transform infrared spectra (FTIR), ¹H nuclear magnetic resonance (NMR) and ³¹P NMR. The monomer is then introduced into poly (methyl methacrylate) (PMMA) matrix via in situ copolymerization to produce a new PMMA based copolymer (PMMA/DOPO-AA). From UV–vis spectra, microscale combustion calorimeter (MCC) and thermogravimetric analyses (TGA) results, the as-fabricated PMMA/DOPO-AA copolymers not only keep relatively high transparency, but also exhibit remarkable improvements in the flame retardancy and thermal stability, such as increased T_0.5 by 60.2°C and limited oxygen index (LOI) by 4.1, and decreased peak heat released rate (PHRR) by 34.7%. Thermal degradation behaviors investigated by real time Fourier transform infrared spectra (RTIR), char structure analysis studied by scanning electron microscope (SEM) and pyrolysis gaseous products studied by TGA coupled with FTIR (TGA-FTIR) demonstrate that the catalytic charring function of DOPO-AA in condensed phase and DOPO flame retardant systems in the gas phase are two key factors for the property enhancements. This work not only provides a promising flame-retardant monomer for polymers, but also will stimulate more efforts on the development of DOPO-containing flame-retardant monomers. Copyright © 2015 John Wiley & Sons, Ltd.

This work reported the preparation and physical properties of biodegradable nanocomposites fabricated using polylactic acid (PLA) and multiple organic modified montmorillonite (MMT). In order to improve the chemical compatibility between PLA and Na-MMT, the surface of Na-MMT was first organically modified by cetyl trimethyl ammonium bromide (CTAB) and resorcinol bis(diphenyl phosphate) (RDP) using ion-exchange and adsorption technique. Both Fourier transform infrared and X-ray diffraction (XRD) results indicated that CTAB and RDP molecules were intercalated into the galleries of MMT sheets to enlarge the interlayer spacing. Then, the PLA/MMT nanocomposites were prepared by a simple melt-blending method. The XRD and TEM results of the nanocomposites indicated that the PLA polymer chains inserted into the galleries of co-modified MMT (C-MMT) and contained disorderedly intercalated layered silicate layers within a PLA matrix. The C-MMT nanolayers were homogenously dispersed in PLA matrix, resulting in various property enhancement. The fabricated PLA/C-MMT nanocomposites with 5.0 wt% addition showed significant enhancements (176%) in the storage modulus compared to that of neat PLA. The thermal stability and fire resistance were also remarkably improved. These improvements are probably because of both the physical barrier effect of the MMT nanosheets and charring effect of the C-MMT. Copyright © 2015 John Wiley & Sons, Ltd.

The objective of this study was to compare the impact of β-iron(III) oxide hydroxide [β-Fe(O)OH] and iron hydroxide modified with phenyl dichlorophosphate [β-Fe(O)OPDCP] on the thermal, combustion, and mechanical properties of ethylene–vinyl acetate (EVA)/magnesium hydroxide (MH) composites. For the EVA/MH composites in combination with these iron-containing co-additives, β-Fe(O)OH and β-Fe(O)OPDCP both led to an increase in the thermal stability at higher temperatures. The results of microscale combustion calorimetry indicate that the peak heat-release rate, total heat release, and heat-release capacity, which are indicators of a material fire hazard, all decreased. Moreover, significant improvements were obtained in the limiting oxygen index (LOI) and Underwriters Laboratories 94 ratings. However, the EVA4 system reached a V-0 rating, whereas the EVA3 system reached a V-2 rating. The LOI values for the EVA3 and EVA4 systems were 35 and 39, respectively. A homogeneous and solid structure of char residue caused by β-Fe(O)OPDCP was observed by scanning electron microscopy. Furthermore, because of the good interfacial compatibility between the fillers and the EVA matrix, the EVA4 system presented better mechanical properties than the EVA3 system. Thermogravimetric analysis/IR spectrometry showed that β-Fe(O)OPDCP reduced the combustible volatilized products of EVA/MH. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40112.

Graphene-supported carbon-coating cobalt and carbon nanoshells (Co/C-GNS and CNS-GNS) were fabricated and their applications in absorbing toxic gases and smoke have been investigated. Co₃O₄-loaded reduced graphite oxide was first prepared via a coprecipitation process, then carbon coatings on cobalt nanoparticles were fabricated by a catalytic carbonization process. The obtained hybrids were characterized by X-ray diffraction, transmission electron microscopy, Raman spectroscopy, N₂ absorption/desorption, and thermogravimetric analysis. Co/C core/shell structure and hollow carbon nanoshells in the size range of 15–22 nm were anchored onto the graphene surfaces. The resultant Co/C-GNS and CNS-GNS performed an important function in CO removal and smoke suppression during the combustion of acrylonitrile-butadiene-styrene. The good performance could be attributed to the combination effect of physical barrier of the GNS, porosity structure of the carbon nanoshells, and carbonization of the Co nanoparticles. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40457.

A polymeric flame retardant (PDEPD) and various amounts of sodium montmorillonite (Na-MMT) nanocomposites with exfoliation structure were prepared via one-step polycondensation, attempting to prepare flame-retardant nanocomposites. The nanocomposites exhibited high thermal stability at high temperature. Based on several comparative studies, we investigated and proposed the possible exfoliation mechanism of Na-MMT in PDEPD substrate. The microscale combustion calorimeter and cone calorimeter results showed the PDEPD/Na-MMT nanocomposites could significantly improve the flame retardancy of polystyrene and polyurethane elastomer (TPU), especially the TPU matrix. This study provides new viewpoint for preparing flame-retardant nanocomposites without surfactants. POLYM. COMPOS., 35:167–173, 2014. © 2013 Society of Plastics Engineers

A new series of microcapsules containing pentaerythritol (PER) and ammonium polyphosphate (APP) with glycidyl methacrylate and butyl methacrylate as shell materials were synthesized by in situ polymerization. The structure and performance of the microencapsulated APP and microencapsulated PER were characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, scanning electron microscopy, and water contact angle. The flame retarded ethylene-vinyl acetate copolymer (EVA) composites were studied by limiting oxygen index, UL-94 test, and cone calorimeter. It was found that the microencapsulation of flame retardants (FRs) with the glycidyl methacrylate and butyl methacrylate lead to a decrease in the particle's water solubility and an improvement of the hydrophobicity. Results also demonstrated that the FR properties of EVA/microencapsulated APP/microencapsulated PER composites were better than those of the EVA/APP/PER composites at the same loading of FRs. The thermogravimetric analysis results reflected that the microencapsulated EVA composites had better thermal stability because of the forming of stable char during the combustion. Copyright © 2013 John Wiley & Sons, Ltd.

A phosphorus and silicon containing liquid monomer (9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide–vinyltrimethoxysilane (DOPO–VTS)) was synthesized by the reaction between DOPO and VTS. DOPO–VTS and methacryloxypropyltrimethoxylsilane were introduced into unsaturated polyester resin to prepare flame retardant UPR/SiO₂ (FR-UPR/SiO₂) hybrid materials by sol–gel method and curing process. DOPO–VTS contributes excellent flame retardancy to UPR matrix, which was confirmed by the limiting oxygen index and microscale combustion calorimeter results. The thermogravimetric analysis (TGA) results indicate that the FR-UPR/SiO₂ hybrid materials possess higher thermal stability and residual char yields than those of pure UPR at high temperature region. The thermal degradation of materials was investigated by TGA/infrared spectrometry (TG-IR) and real-time infrared spectrometry (RT-IR), providing insight into the thermal degradation mechanism. Moreover, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy (XPS) were used to explore the morphologies and chemical components of the residual char. Copyright © 2013 John Wiley & Sons, Ltd.

A new phosphorous- and nitrogen-containing reactive monomer, DMPMA, was first synthesized by nucleophilic substitution reaction of 2-(6-oxido-6H-dibenz[c,e][1,2]oxaphos-phorin-6-yl) methanol, N-hydroxymethyl acrylamide and methyldichlorophosphate. The copolymer of styrene (St) and DMPMA (poly(St-co-DMPMA)) was prepared and then characterized by Fourier transform infrared, differential scanning calorimetry, thermogravimetric analysis (TGA), microscale combustion calorimeter and steady-state tube furnace (SSTF). The results proved that poly(St-co-DMPMA) was well synthesized, while the glass transition temperature of the copolymer was decreased with increasing DMPMA content. The TGA results showed that the initial degradation temperature of poly(St-co-DMPMA) decreased, but its char yield and decomposition temperature improved compared to that of pure polystyrene. After incorporating DMPMA, the fire performance of the copolymer was significantly improved. The results obtained from the SSTF indicated that the carbon monoxide and smoke yield density were increased due to the incomplete combustion of the copolymer. Copyright © 2014 John Wiley & Sons, Ltd.

A reactive extrusion process was developed to fabricate polymer/graphene nanocomposites with good dispersion of graphene sheets in the polymer matrix. The functionalized graphene nanosheet (f-GNS) activated by diphenylmethane diisocyanate was incorporated in thermoplastic polyester elastomer (TPEE) by reactive extrusion process to produce the TPEE/f-GNS masterbatch. And then, the TPEE/f-GNS nanocomposites in different ratios were prepared by masterbatch-based melt blending. The structure and morphology of functionalized graphene were characterized by Fourier transform infrared, X-ray photoelectron spectroscopy, X-ray diffraction and transmission electron microscopy (TEM). The incorporation of f-GNS significantly improved the mechanical, thermal and crystallization properties of TPEE. With the incorporation of only 0.1 wt% f-GNS, the tensile strength and elongation at break of nanocomposites were increased by 47.6% and 30.8%, respectively, compared with those of pristine TPEE. Moreover, the degradation temperature for 10 wt% mass loss, storage modulus at −70°C and crystallization peak temperature (T_cp) of TPEE nanocomposites were consistently improved by 17°C, 7.5% and 36°C. The remarkable reinforcements in mechanical and thermal properties were attributed to the homogeneous dispersion and strong interfacial adhesion of f-GNS in the TPEE matrix. The functionalization of graphene was beneficial to the improvement of mechanical properties because of the relatively well dispersion of graphene sheets in TPEE matrix, as suggested in the TEM images. This simple and effective approach consisting of chemical functionalization of graphene, reactive extrusion and masterbatch-based melt blending process is believed to offer possibilities for broadening the graphene applications in the field of polymer processing. Copyright © 2014 John Wiley & Sons, Ltd.

The main aim of this work was to investigate the synergistic effect of expandable graphite (EG) and aluminum hypophosphite (AHP) on the flame retardancy of rigid polyurethane foams (RPUFs). A series of flame retardant RPUF containing EG and AHP were prepared by one-shot and free-rise method. The flame retardant, thermal degradation, and combustion properties of RPUF hybrids were characterized through limiting oxygen index (LOI) test, vertical burning (UL-94) test, thermogravimetric analysis and microscale combustion calorimeter. The LOI and UL-94 results showed that the RPUF sample with 10 wt% EG and 5 wt% AHP passed UL-94 V-0 rating and reached a relatively high LOI value of 28.5%, which is superior over other EG/AHP ratios in RPUF at the equivalent filler loading. Microscale combustion calorimeter results revealed that the incorporation of EG and AHP into RPUF reduced the peak heat release rate and total heat release, thus decrease the fire risk of RPUF significantly. Incorporation of EG and AHP improved the thermal stability of RPUF as observed from the thermogravimetric analysis results and also enhanced the thermal resistance of char layer at high temperature from scanning electron microscopy and Raman spectroscopy. Moreover, it could be seen from thermogravimetric analysis/infrared spectrometry spectra that the addition of EG and AHP significantly decreased the combustible gaseous products such as hydrocarbons and ethers. Finally, the synergistic mechanism in flame retardancy was discussed and speculated. Copyright © 2014 John Wiley & Sons, Ltd.

In this paper, three different kinds of typical transition metal molybdates (AMoO₄, A = Co, Ni, Cu) were synthesized via a hydrothermal method. X-ray diffraction and scanning electron microscopy (SEM) were used to characterize their structures. Then, the synthesized molybdates were incorporated into acrylonitrile-butadiene-styrene (ABS) matrix via a masterbatch-based melt blending method. SEM images showed that transition metal molybdates (AMoO₄, A = Co, Ni, Cu) are homogeneously dispersed in the ABS matrix. Thermogravimetric analysis (TGA) results indicated that the introduction of these transition metal molybdates (AMoO₄, A = Co, Ni, Cu) could accelerate the degradation of ABS, especially for the CuMoO₄. The initial thermal degradation temperatures are decreased by 9–12°C for ABS/CoMoO₄ and ABS/NiMoO₄ composites. But for the ABS/CuMoO₄ composite, it is decreased by 45°C. Meanwhile, the peak of heat release rate is decreased by 10%–13% for ABS/CoMoO₄ and ABS/NiMoO₄ composites, and it is decreased by 26% for ABS/CuMoO₄ composite. Moreover, TGA/infrared spectrometry was used to investigate the smoke suppression effect of CuMoO₄ in ABS indirectly; it showed that the addition of CuMoO₄ inhibits the release of hydrocarbons, aromatic compounds, and CO and promotes the generation of CO₂. Copyright © 2014 John Wiley & Sons, Ltd.

Poly (butylene succinate) (PBS) nanocomposites with titanium dioxide nanotubes (TNTs) or hydroxyapatite nanorods (HAP) were prepared, and the effect of the nano-inorganics on the nonisothermal crystallization and melting properties of PBS were studied in detail by differential scanning calorimeter. The nonisothermal crystallization kinetics of PBS and its nanocomposites were analyzed by the Avrami, Ozawa, and Mo methods. It is found that the presence of TNTs increases the crystallization temperature and rate of PBS composites, but decreases the crystallization activation energy and crystallinity. By comparison, the crystallization rate of the PBS composite is decreased with the addition of HAP. The melting, recrystallization, and remelting mechanism results in the formation of two melting endothermic peaks during the melting process of neat PBS and its nanocomposites. The model proposed by Mo could successfully describe the nonisothermal crystallization process of PBS and its nanocomposites. At a given crystallinity, the F(t) values decrease in the order of PBS/HAP, PBS, and PBS/TNTs. © 2014 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40335.

In this paper, three typical transition metal phosphide nanocrystallines (M_xP_y, M = Ni, Co, and Cu) were synthesized by a novel hydrothermal method, and their structures were characterized by X-ray diffraction and transmission electron microscopy. Then they were used as synergistic agents with intumescent flame retardant (IFR) to improve the fire safety of polypropylene (PP). Thermogravimetry analysis (TGA) results indicated that the introduction of these synergists could improve the thermal stability and char yields of the PP/IFR system. The addition of 2 wt.% Ni₁₂P₅ and Co₂P increased the limiting oxygen index values of the PP/IFR system significantly from 28% to 36% and 34%, respectively, and the system could reach V-0 rating. The cone calorimeter test results revealed that the combination of transition metal phosphide nanocrystallines and IFR system could result in excellent flame retardancy. The incorporation of these synergists into IFR led to a remarkable influence on charring of PP composites as revealed by TGA and cone data. The morphological structure of char residue proved that the addition of transition metal phosphide nanocrystallines was capable of forming a compact and homogeneous char on the surface, which turned out to be of most importance for the flame retardancy. Thermogravimetric analysis/infrared spectrometry results indicated that the flame retardant mechanism of PP/IFR/M_xP_y (M = Ni, Co, and Cu) system was in the condensed phase rather than in the gas phase. Copyright © 2014 John Wiley & Sons, Ltd.

Phenolic foam exhibits outstanding flame, smoke and toxicity properties, good insulation properties and low production costs. However, the brittleness and pulverization of phenolic foam have severely limited its application in many fields. In this study, a novel phosphorus-containing polyurethane prepolymer (DOPU) modifier was firstly synthesized, and then the foaming formula and processing of toughening phenolic foam modified with DOPU and glass fiber were explored. The structure and reactive behavior of prepolymer and phenolic resin were investigated using Fourier transform infrared spectroscopy. The effects of DOPU and glass fiber on the apparent density, compressive strength, bending strength and water absorption were investigated. The results suggested that the apparent density, compressive strength and bending strength of modified phenolic foam tended to increase irregularly with increasing content of DOPU. The addition of DOPU led to lower water absorption of glass fiber-filled foam. Thermal stability and flame retardancy were examined using thermogravimetric analysis and limiting oxygen index (LOI) tests. It was found that foam with 3% DOPU and 0.5% glass fiber added exhibited good thermal stability and high char yields. The LOI value of modified phenolic foams decreased with increasing DOPU content, but it still remained at 41.0% even if the amount of modifier loaded was 10 wt%. © 2012 Society of Chemical Industry

A novel phosphorus- and silicon-containing polyurethane prepolymer (PSPUP) was synthesized by the chemical reaction of phenyl dichlorophosphate with hydroxy-terminated polydimethylsiloxane (HTPDMS) and subsequently with toluene-2,4-diisocyanate. The structure of PSPUP was confirmed by Fourier transform infrared spectroscopy and ¹H nuclear magnetic resonance. Afterward, a series of phenolic foams (PF) with different loadings of PSPUP toughening agent were prepared. The apparent density and scanning electron microscopy results showed that the addition of PSPUP can increase the apparent density of phenolic foam. The compressive, impact and friability test results showed that the incorporation of PSPUP into PF dramatically improved the compressive strength, impact strength, and reduced the pulverization ratio, indicating the excellent toughening effect of PSPUP. The limiting oxygen index of PSPUP modified phenolic foams remained a high value and the UL-94 results showed all samples can pass V0 rating, indicating the modified foams still had good flame retardance. The thermal properties of the foams were investigated by thermogravimetric analysis under air atmosphere. Moreover, the thermal degradation behaviors of the PF and PSPUP/PF were investigated by real-time Fourier transform infrared spectra. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013

This work reports the selective preparation of different kinds of carbon nanomaterials through carbonization of polymethacrylate (PMA)/organophilic clay (Oclay) composite by just changing the catalyst precursors. The morphologies and structures of the carbon materials were characterized by Scanning and Transmission electron microscopy, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy. The result indicated that the catalyst precusors had a strong influence on the morphologies and yields of the obtained products. Carbon nanoflakes were produced when iron oxide was used as the catalyst precursor, cobalt oxide favored the formation of carbon nanospheres, while carbon nanotubes occurred over nickel oxide. The presence of Oclay plallets was determined to prevent the pyrolytic carbon species of PMA in the system from escaping, thus relatively more carbon nanomaterials were obtained. Based on the experimental observations, a possible mechanism was discussed for illustrating the growth process. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1029-1037, 2013

High fire hazards of glass-fiber reinforced polymer composites have greatly limited their development and application. To reduce their flammability, the composites have to be treated with flame retardants. This work examines the use of three trivalent metal (Al, La, Ce) hypophosphites as halogen-free flame retardants for glass-fiber reinforced poly(1,4-butylene terephthalate) (GRPBT) composites. The aim of this study is to quantitatively investigate the effect of metal hypophosphites on the thermal decomposition and combustion behavior of GRPBT composites by means of cone calorimeter and thermogravimetry coupled with Fourier transform infrared spectroscopy (TG-FTIR) techniques. The peak heat release rate and total smoke production of GRPBT/cerium hypophosphite (CHP) composite evaluated by cone calorimeter are reduced, respectively, by around 76 and 44% compared to the results of GRPBT. The volatilized esters measured by TG-FTIR in the decomposition of GRPBT/CHP are decreased by about 69%. The results showed that rare earth hypophosphites can effectively inhibit the thermal decomposition and combustion behaviors of GRPBT in comparison with aluminum hypophosphite. POLYM. COMPOS., 34:1832–1839, 2013. © 2013 Society of Plastics Engineers

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

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.

Microencapsulated ammonium polyphosphate (MAPP) with polyurethane resin has been prepared by in situ polymerization. The combination of MAPP and boron phosphate (BP) on the flammability properties of thermoplastic polyurethane (TPU) was studied by vertical burning (UL-94) tests, limiting oxygen index tests, cone calorimetry (CONE), and microscale combustion calorimeter (MCC) whereas thermal stability was investigated by thermogravimetric analysis and real-time Fourier transform infrared. Results showed that a suitable substitution of MAPP by BP could improve flame retardancy of the TPU/MAPP composites and TPU composites with MAPP/BP (15.5/2 wt%) achieving UL-94 V-0 rating. The CONE and MCC data showed synergistic effects between BP and MAPP in the composites. Copyright © 2011 John Wiley & Sons, Ltd.

In this work, we reported the synthesis, characterization of Ce-doped titania nanotubes (Ce-TNTs), and application in flame retardancy of an intumescent flame-retardant polystyrene (PS/IFR) system. The flame retardancy of polystyrene (PS) composite that was composed of pentaerythritol, microencapsulated ammonium polyphosphate, and PS was enhanced significantly by adding a small amount (0.1 wt%) of (Ce-TNTs). The thermal properties of the flame-retardant PS were investigated by thermogravimetric analysis, limiting oxygen index (LOI), vertical burning test (UL-94), scanning electronic microscopy, dynamic mechanical thermal analysis, and the real-time Fourier transform infrared spectrometry (FTIR). The maximal decomposition rate temperature of PS/IFR containing Ce-TNTs in air is much higher than that of other PS composite without Ce-TNTs. The LOI value of PS/IFR that contained 0.1 wt% of Ce-TNTs was increased from 27.0 to 28.5, and the UL-94 rating was also enhanced to V-0 from no rating when the total loading of additive was the same. The real-time FTIR showed that the degradation process was changed after the addition of TNTs. All results indicated that Ce-TNTs had a significant synergistic effect on the flame retardancy of PS/IFR. Copyright © 2012 John Wiley & Sons, Ltd.

Urea-modified lignin was prepared according to the Mannich reaction and well characterized by Fourier transform infrared spectrometer, elemental ananlyses, and scanning electron microscopy (SEM). Ammonium polyphosphate (APP) and urea-modified lignin were added into poly(lactic acid) (PLA) as a novel intumescent flame-retardant (IFR) system to improve flame retardancy of PLA. The flammability of IFR–PLA composites was studied using limiting oxygen index, UL-94 vertical burning method and cone calorimeter test, and their thermal stability was evaluated by thermogravimetric analysis. The results showed that the urea-modified lignin combined with APP exhibited much better flame retardancy and thermal stability than that of the combination of virgin lignin and APP. The improvement may be attributed to the better char morphology with more phosphoric char evidenced by SEM and X-ray photoelectron spectroscopy. POLYM. ENG. SCI., 2012. © 2012 Society of Plastics Engineers

This work aims to develop halogen-free poly(1,4-butylene terephthalate) (PBT) composites with enhanced flame retardancy using ecofriendly flame retardants, aluminum hypophosphite (AHP) and melamine derivatives (melamine polyphosphate and melamine cyanurate). Microscale combustion calorimetry and thermal gravimetric analysis/infrared spectrometry (TG-IR) technique were used to investigate the potential fire hazards of these PBT composites. For the PBT composites with the incorporation of AHP and melamine derivatives, the heat release capacity (HRC) which is an indicator of a material fire hazard was significantly reduced, and the intensities of a variety of combustible or toxic gases detected by TG-IR technique were remarkably decreased. Moreover, a loading of 20 wt % flame retardant mixture fulfilled the PBT composites high limited oxygen index (LOI) and V-0 classification in UL 94 testing. An intumescent flame retarded mechanism was speculated in this work, because numerous bubble-like char residues were found on the surface of the samples containing flame retardant mixture after LOI testing. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011

The progress of flame retarded polymer nanocomposites and coatings in China over the past decades are described in this review. Emphasis on flammability performance of polymer nanocomposites containing nanofillers, mainly layered inorganic compounds, nanofibers and nanoparticles, combined with conventional flame retardant additives are addressed based on the open literature. Polymeric coatings with improved flame retardancy prepared using a wide variety of additives and UV-curing technology are also introduced. Derived from this research, the combination of multiple methods and technologies including catalyst and nanotechnology, is predicted to have a high probability to enhance char formation and improve the flame retardancy of polymeric materials. Copyright © 2011 John Wiley & Sons, Ltd.

Ferric pyrophosphate (FePP) was added to an ammonium polyphosphate (APP)—pentaerythritol (petol) intumescent flame retardant (IFR) system in polypropylene (PP) matrix, with subsequent investigation into the synergistic effect between FePP and the IFRs. Limited oxygen index (LOI), UL-94 test and cone calorimeter test were employed to study the flame retardance of the synthesized flame retardant PP composites. Thermogravimetric analysis (TGA) and thermogravimetric analysis-infrared spectrometry (TG-IR) were used to study their thermal degradation characteristics and gas products. TG-IR results demonstrate that there is no Fe (CO)₅ produced from PP/IFR/FePP system, which implies that the flame retardant mechanism of PP/IFR/FePP system is in the condensed phase rather than in the gas phase. Real time FTIR and X-ray photoelectron spectroscopy (XPS) were used to monitor the thermal oxidative stability and the high temperature performance of the flame retardant PP composites. The real time FTIR spectra show that all peaks around 2900 cm⁻¹ almost disappear at 380°C for the PP/IFR system, meaning that PP decomposes completely at this temperature. But after the addition of 2 wt%wt% FePP, the peaks still exist till 400°C. XPS shows that the aliphatic carbon atom content in PP/23 wt%wt% IFR/2 wt%wt% FePP (63.8%) is much higher than the one without FePP, and the total oxygen atom content in PP/23 wt%wt% IFR/2 wt%wt% FePP is just 19.1%, while the one in PP/25 wt% IFR is as high as 35.7%. Copyright © 2009 John Wiley & Sons, Ltd.

Phosphorus, nitrogen-containing monomer, acryloxyethyl phenoxy phosphorodiethyl amidate (AEPPA), was synthesized and copolymerized with styrene (St). Nanocomposites of polystyrene and poly(St-co-AEPPA) with various amounts of Mg-Al layered double hydroxide (LDH) were then prepared by in situ bulk polymerization. Structure and morphology of the nanocomposites were investigated by Fourier transform infrared (FTIR), X-ray diffraction (XRD), and transmission electron microscopy (TEM). The nanocomposites were also examined by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and microscale combustion calorimeter (MCC) to evaluate the thermal properties and flammability. Intercalated or exfoliated structures were obtained for all the nanocomposites. The results from XRD and TEM showed the LDH layers dispersed better in poly(St-co-AEPPA) than those in PS matrix. Decrease in thermal stability and enhancement in char residues were observed for poly(St-co-AEPPA) nanocomposites compared with PS nanocomposites at the same LDH loading. The addition of LDH can obviously reduce the heat release capacity (HRC) and total heat release (THR) of PS. Moreover, further reductions in HRC and THR were found in poly(St-co-AEPPA) nanocomposites. The reduction in flammability was attributed to the lower maximum mass loss rate (MMLR) and higher char residues of the nanocomposites. POLYM. COMPOS., 2011. © 2010 Society of Plastics Engineers

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.

The flame retardancy mechanisms of poly(1,4-butylene terephthalate) (PBT) containing microencapsulated ammonium polyphosphate (MAPP) and melamine cyanurate (MC) were investigated via pyrolysis analysis (thermogravimetric analysis (TGA), real-time Fourier transform infrared (FTIR), TG-IR), cone calorimeter test, combustion tests (limited oxygen index (LOI), UL-94), and residue analysis (scanning electron microscopy (SEM)). A loading of 20 wt% MC to PBT gave the PBT composites an LOI of 26%, V-2 classification in UL-94 test and a high peak heat release rate (HRR) in cone calorimeter test. Adding APP to PBT/MC composites did not improve their flame retardancy. In comparison with the addition of ammonium polyphosphate (APP) to PBT, MAPP with silica gel shell and MAPP with polyurethane shell both promoted the intumescent char-forming and improved the flame retardancy of PBT through different mechanisms in the presence of MC. These two halogen-free PBT composites with V-0 classification according to UL-94 test were obtained; their LOI were 32 and 33%, respectively. Copyright © 2010 John Wiley & Sons, Ltd.

A novel phosphorus monomer (PDHA) has been synthesized through phenyl dichlorophosphate (PDPC) reacting with 2-hydroxyethyl acrylate (HEA). The structure of PDHA was characterized by Fourier transform infrared spectroscopy (FTIR) and ¹H nuclear magnetic resonance spectroscopy (¹H NMR). A series of UV curable resins were manufactured by blending PDHA with triglycidyl isocyanurate acrylate (TGICA) at different weight ratios. The fire performance was examined by micro-scale combustion calorimeter (MCC) and limiting oxygen index (LOI). The results obtained from MCC indicated that the addition of PDHA to TGICA reduced the HRR and HRC. In addition, the LOI values varied from 28 to 34. The char residues of the composites were observed by scanning electron microscopy (SEM). Their thermal degradation behavior was investigated by thermogravimetric analysis and real time FTIR analysis (RT-FTIR). The test results indicated that when the weight ratio of PDHA/TGICA = 1:1, the onset temperature of the composite was highest and the most char residue at 700°C was observed. RT-FTIR showed that the phosphate group of PDHA first degraded to form poly(phosphoric acid)s at around 300°C, which had the major contribution to form the compact char to protect the sample from further degradation. Copyright © 2010 John Wiley & Sons, Ltd.

The bisphenol A epoxy acrylate resin (EA) containing a small amount of layered double hydroxide (LDH) was cured within seconds under UV irradiation at ambient temperature. Its microstructure was characterized by X-ray diffraction (XRD). The combustion behavior of the coating was examined by the Microscale Combustion Calorimeter (MCC) and limiting oxygen index (LOI). The results obtained from MCC and LOI indicated that the addition of LDH into EA could decrease the peak of heat release rate (HRR) for the films and increase the LOI value of the films. Thermal behavior of the cured films was studied by thermogravimetric analysis (TGA). The results for TGA indicated that with increase in the contents of LDH, the residual char of UV-cured films increased at 600 °C. The evolved products for UV-cured films were characterized using thermogravimetric analysis/infrared spectrometry (TGA-IR). It was implied that the mechanism of thermal degradation for EA0 was different from EA4. Viscoelastic property of photo-cured hybrid materials was evaluated by dynamic-mechanical analysis. The effect of LDH on the properties of UV-curable films was critically evaluated in this paper. Copyright © 2010 John Wiley & Sons, Ltd.

A novel intumescent gel-silica/ammonium polyphosphate core-shell flame retardant (MCAPP), which contains silicon, phosphorus, and nitrogen, has been prepared by in situ polymerization. The structure of MCAPP was characterized by Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS). The properties of MCAPP were investigated by water solubility, hydrophilicity, and morphological determination. The flame retardancy and thermal stability of polyurethane (PU) composite with MCAPP were evaluated by limiting oxygen index (LOI), UL-94 test, cone calorimetry, and thermogravimetric analysis (TGA). The results showed that MCAPP could decrease the heat release rate (HRR) and increase the thermal stability of PU materials greatly. Finally, water-resistant properties of PU/FR composites were also studied. Copyright © 2010 John Wiley & Sons, Ltd.

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 (T_g) 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.

Polymer/α-titanium phosphate (nano)composites are reported for the first time in this paper. The α-titanium phosphate was synthesized via the hydrothermal method and organically modified by ethylamine intercalation. Flame retardant polypropylene/α-titanium phosphate (nano)composites were prepared by melt blending. The titanium phosphates and (nano)composites were characterized and enhanced thermal stability, flame retardancy, and mechanical properties were obtained. Thermogravimetric analysis results showed an increase of 65°C in the maximum decomposition temperature and a 34% reduction in the peak value of derivative weight curve, demonstrating enhanced thermal stability. Improved mechanical properties, including elongation at break (70%), impact strength (29%), Young's modulus (11%), and hardness (35%), were obtained. Materials flame retardancy was also improved according to limiting oxygen index and vertical burning test. Probable mechanism for (nano)composites properties enhancements are discussed. Copyright © 2011 John Wiley & Sons, Ltd.

Two intumescent flame-retardant (IFR) additives, IFR-I and IFR-II, were synthesized and their structure was confirmed by Fourier transform infrared spectroscopy and nuclear magnetic resonance. Polylactide (PLA) was modified by the two IFRs to obtain flame-retardant composites. The flammability of the PLA/IFR composites was characterized by the vertical burning test UL-94 and limiting oxygen index. The limiting oxygen index values of the PLA composites increased with increase of IFR content. The PLA composite with 20 wt% IFR-I could pass the UL-94 V0 rating, while the composite with 30 wt% IFR-II could not. The results of pyrolysis combustion flow calorimetry showed that the heat release capacity of PLA composites with 30 wt% IFR-I decreased 43.1% compared with that of pure PLA. The thermal degradation and gas products of PLA/IFR-I systems were monitored by thermogravimetric analysis and thermogravimetric analysis infrared spectrometry. Scanning electron microscopy was used to investigate the surface morphology of the char residue. Copyright © 2011 Society of Chemical Industry

A series of UV-curable flame-retardant resins was obtained by blending phosphate acrylate (BTP) in different ratios with epoxy acrylate resin (EA). The flammability was characterized by limiting oxygen index (LOI), UL 94 flammability rating and cone calorimeter, and the thermal degradation of the flame-retardant resins was studied using thermo gravimetric analysis (TGA), and real-time Fourier transform infrared (RTFTIR). The results indicated that the flame-retardant efficiency increases with the addition of BTP. The heat release rate with the addition of BTP decreases greatly. The TGA data showed that EA/BTP blends have lower initial decomposition temperatures and higher char residues than pure EA, whereas BTP has the lowest initial decomposition temperature and the highest char residue. The RTFTIR study indicates that the EA/BTP blends have lower thermal oxidative stability than the pure EA. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010

A series of polyurethane (PU) microencapsulated ammonium polyphosphate (MCAPP) were prepared by in situ polymerization from toluene-2,4-diisocyanate (TDI), polyethylene glycol (PEG), and pentaerythtritol (PER). And the structure was characterized by Fourier transform infrared spectroscopy (FTIR) and X-ray photoelectron spectroscopy (XPS). Then it chose the optimal PEG constituent to design microcapsule from scanning electron microscopy (SEM) and water solubility test. The combustion and thermal degradation behaviors of PU blended APP or MCAPP were investigated by thermogravimetric analysis (TGA), UL-94 test, and microcombustion calorimetry. The results showed that the PU/MCAPP had better thermal stability and flame retardance, due to the stable char forming by APP and PU shell. Moreover, the water resistance of flame retarded PU composite was greatly improved. Copyright © 2009 John Wiley & Sons, Ltd.

Silicone rubber (SR)/organoattapulgite (OAT) composites were prepared with γ-irradiation crosslinking at a dose range varied from 30 to 300 kGy. Natural fibrillar silicate attapulgite (AT) was modified by silane coupling agent, and the obtained OAT was used as reinforcing fillers in SR. The effect of irradiation doses on the degree of crosslinking of SR/OAT composites was determined by solvent swelling method. It was found that the molecular weight between crosslinks (M_c) reduced with the increase in irradiation doses. Moreover, the addition of OAT to SR matrix promoted an increase in the crosslinking density of the composites because of the presence of the active crosslinking sites of OAT. The mechanical properties of the SR/OAT composites including tensile strength, elongation at break, and Shore A hardness subjected to various irradiation doses were studied. The experimental results showed that the tensile strength, elongation at break, and Shore A hardness were all improved significantly in the presence of OAT, which indicated that OAT was an alternative reinforcing filler of SR. In addition, the effect of various irradiation doses on the mechanical properties of SR and SR/OAT composites was also investigated. POLYM. COMPOS., 2010. © 2009 Society of Plastics Engineers

Epoxy resin (EP)/polyhedral oligomeric silsesquioxane (POSS) hybrids were prepared based on octavinyl polyhedral oligomeric silsesquioxane (OVPOSS) and phosphorus-containing epoxy resin (PCEP). The PCEP was synthesized via the reaction between bisphenol A epoxy resin (DGEBA) and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO). The structure and morphology of PCEP/OVPOSS hybrids were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. Differential scanning calorimetry revealed that the PCEP/OVPOSS hybrids possessed higher glass transition temperatures than that of PCEP. The thermal stability of the PCEP/OVPOSS hybrids was studied using thermogravimetric analysis (TGA). The TGA results illustrated the synergistic effect of phosphorus–silicon of flame retardancy: phosphorus promotes the char formation, and silicon protects the char from thermal degradation. The thermal degradation mechanism of the PCEP/OVPOSS hybrids was investigated by real time Fourier transform infrared spectra and pyrolysis/gas chromatogram/mass spectrometry (Py-GC/MS) analysis. It was found that OVPOSS migrated to the surface of the matrix and then sublimed from the surface in nitrogen; whereas, the vinyl groups of OVPOSS were oxidated to form a radical trap which could react with pyrolysis radicals derived from PCEP to form the branched and crosslinked structure in air. The combustion behaviors of the hybrids were evaluated by micro combustion calorimetry. The addition of OVPOSS obviously decreased the value of peak heat release rate and total heat release of the hybrids. Moreover, scanning electron microscopy (SEM) and X-ray photoelectron spectroscopy were used to explore the char residues of the PCEP and the hybrids. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 693–705, 2010

Effect of metallic oxides on flame retardancy and the thermal stability of styrene butadiene rubber (SBR) composites based on ammonium polyphosphate (APP) and pentaerythritol (PER) was studied by the limiting oxygen index (LOI), UL 94, the cone calorimeter tests, and thermogravimetry analysis (TGA), respectively. Scanning electron microscopy (SEM) and wide-angle X-ray diffraction (WAXD) were used to analyze the morphological structure and the component of the residue chars formed from the SBR composites accordingly. The addition of zirconium dioxide (ZrO₂) at a loading of 3.4 phr could improve the UL 94 test rating of the composite to V-0. The TGA data illustrated that the metallic oxides could enhance the thermal stability of the SBR/Intumescent flame retardant additives (IFRs) composites at high temperature and increase the residue. Cone calorimeter test gave much clear evidence that the incorporation of ZrO₂ into SBR/IFRs composites resulted in the significant deduction of the heat release rate (HRR) values, and the SEM images showed that the char layers of the composites containing the metallic oxides became more compact. From the WAXD pattern, zirconium phosphate (ZrP₂O₇) may be formed by the reaction between ZrO₂ and APP. Due to the addition of ZrO₂ and the formation of ZrP₂O₇, the flame retardancy of the composite was improved. Copyright © 2009 John Wiley & Sons, Ltd.

In this article, the combination of silicone rubber (SR) elastomer with synthetic iron montmorillonite (Fe-MMT) to form a kind of new flame-retardant system based on an ethylene–vinyl acetate (EVA) copolymer is first reported. Also, the flame retardancy of the EVA/SR/Fe-MMT hybrid are compared with that of EVA/SR/natural sodium montmorillonite. The structures of the nanocomposites were characterized with X-ray diffraction and transmission electron microscopy. Cone calorimeter tests and thermogravimetric analysis were used to evaluate the flame-retardant properties and thermal stability of the composites, respectively. In addition, tensile tests were carried out with a universal testing machine, and the morphology of the fracture surface was observed with environmental scanning electron microscopy. We found that SR/organophilic montmorillonite (Fe-OMT) was more effective in reducing the primary peak heat release rate of the nanocomposite, and the EVA/SR/Fe-OMT hybrid had a higher thermal stability in the deacetylated polymer than EVA/SR/sodium organophilic montmorillonite. Moreover, the exfoliated EVA/SR/Fe-OMT nanocomposite displayed excellent mechanical properties because of a better dispersion of Fe-OMT in the polymer matrix, and a possible mechanism is discussed. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009

A novel star polyurethane acrylate (SPUA) used for UV-curable coating was prepared from 2,4-toluene diisocyanate, 2-hydroxyethyl arcylate, and hexakis(2-hydroxyethyl)melamine, and characterized using FTIR, ¹H-NMR, and elemental analysis. Its UV curing behaviors investigated via FTIR clearly indicated that this monomer could be cured rapidly at air atmosphere. The conversion of the unsaturated bond of the cured monomer sample is near to 72% after exposed under UV light for 40 sec. The hardness, flexibility, and mechanical properties of the cured film were also investigated. The thermal stability of the cured film was studied using thermogravimetric analysis (TGA) and real time Fourier transform infrared (RTFTIR). Results showed that this oligomer has some superior properties and can be used for UV curing coating. Copyright © 2007 John Wiley & Sons, Ltd.

A series of UV-curable intumescent flame retardant resins was obtained by blending phosphate triacrylate (TAEP) in certain ratios with star poly(urethane acrylate) (SPUA) oligomer. The flammability of the cured films was characterized by limited oxygen index (LOI), UL 94, and the cone calorimeter. The results showed that the cured TAEP/SPUA samples greatly expanded while burning. A distinct synergistic effect was found between TAEP and SPUA. TAEP2 sample showed the highest LOI value (41) among all resins. The cone calorimeter results showed that the peak heat release rates and carbon monoxide yield decreased to the approximate level. The degradation was monitored by thermogravimetric analysis and real-time Fourier transform infrared spectroscopy. A degradation mechanism is suggested in which the phosphate group in TAEP first degraded to form poly(phosphoric acid)s, which further catalyzed the degradation of the material to form char with emission of carbon dioxide and nitrogen volatiles from SPUA, leading to the formation of expanding char. The morphologic structures of crusts of the formed chars were observed by scanning electron microscopy, demonstrating the synergistic effect between TAEP and SPUA. Copyright © 2008 John Wiley & Sons, Ltd.

Nanoporous nickel phosphate VSB-1 was synthesized by hydrothermal method and its structure was characterized. Then VSB-1 was added to the ammonium polyphosphate (APP) and pentaerythritol (petol) system in a polypropylene (PP) matrix for the first time, and the synergistic effect of VSB-1 with intumescent flame retardants (IFR) was studied. With the addition of 2 wt% VSB-1 and 23 wt% IFR, the LOI value of PP/IFR composites increased from 28.0 to 35.5. The UL-94 test showed that PP with 20% IFR burned and had no rating, but with the addition of 2 wt% of VSB-1 and 18% of IFR, it could reach V-0 rating. The results of the X-ray photoelectron spectroscopy (XPS) showed that the ratios of P/C and N/C of PP/IFR/VSB-1 systems changed significantly from 0.133 to 0.205 (54% increase) and from 0.0328 to 0.047 (45.4% increase), respectively under 800°C for 10 min. Compared with the organophilic montmorillonite (OMT), 4 Å zeolite, and zinc tetraborate (ZB), VSB-1 showed better synergistic effect at the same loading. Copyright © 2008 John Wiley & Sons, Ltd.

The synergistic effect between a char forming agent (CFA) and microencapsulated ammonium polyphosphate (MAPP) on the thermal and flame retardancy of polypropylene (PP) are investigated by limiting oxygen index (LOI), UL-94 test, cone calorimetry, thermogravimetric analysis (TGA), scanning electron micrograph (SEM), and water resistance test. The results of cone calorimetry show that heat release rate peak (PHRR), total heat release (THR), and the mass loss of PP with 30 wt% intumescent flame retardant (IFR, CFA/MAPP = 1:2) decreases remarkably compared with that of pure PP. The HRR, THR, and mass loss decrease, respectively from 1140 to 100 kW/m², from 96 to 16.8 MJ/m², and from 100 to 40%. The PP composite with CFA/MAPP = 1:2 has the best water resistance, and it can still obtain a UL-94 V-0 rating after 168 hr soaking in water. Copyright © 2008 John Wiley & Sons, Ltd.

Ethylene-octene copolymer (POE)-based nanocomposites were prepared from POE or maleic anhydride grafted POE with organo-modified montmorillonite (OMT) using melt blending technique. Their morphology, flammability, and crystallization behavior were investigated by X-ray diffraction (XRD), transmission electron microscopy (TEM), cone calorimeter, and differential scanning calorimetry (DSC). XRD and TEM studies confirmed the intercalation of clay layers within the POE matrix whereas the exfoliation throughout the maleated POE matrix. Cone calorimetry results exhibited that the reduction in heat release rate of exfoliated maleated-POE/OMT nanocomposite was greater than that of intercalated POE/OMT nanocomposite. The DSC results suggested that the nonisothermal kinetics crystallization of the exfoliated nanocomposite corresponded to tridimensional growth with heterogeneous nucleation. POLYM. COMPOS., 2008. © 2008 Society of Plastics Engineers

In this work, Fe-montmorillonite (Fe-MMT) is synthesized and used as a synergistic agent in ethylene vinyl acetate/magnesium hydroxide (EVA/MH) flame retardant formulations. The synergistic effect of Fe-MMT with magnesium hydroxide (MH) as the halogen-free flame retardant for ethylene vinyl acetate (EVA) is studied by thermogravimetric analysis (TGA), limiting the oxygen index (LOI), UL-94, and cone calorimetry test. Compared with that of Na-MMT, it indicates that the synergistic effects of Fe-MMT enhance the LOI value of EVA/MH polymer and improve the thermal stability and reduce the heat release rate (HRR). The structure and morphology of nanocomposites are studied by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The mechanical properties of the EVA composites have also been studied here, indicating that the use of Fe-MMT reduces the amount of inorganic fillers. MH hence enhances the mechanical properties of the EVA composite while keeping the UL-94 V-0 rating. Copyright © 2008 John Wiley & Sons, Ltd.

Phosphorus-containing trimethoxysilane (DGTH) was blended with Star polyurethane acrylate (SPUA) in different ratios to obtain a series of UV curable intumescent flame retardant resins. The fire properties were characterized by limiting oxygen index (LOI) and cone calorimetry. A distinct synergistic effect was found between SPUA and DGTH. The thermal degradation was characterized by thermogravimetric analysis and real time Fourier-transform infrared spectroscopy. The TG results have been found to correlate well with the LOI results. A degradation mechanism has been suggested that the 9,10-dihydro-oxa-10-phosphaphenantrene-10-oxide (DOPO) group in DGTH first degraded to form poly(phosphoric acid)s, which further catalyzed the degradation of the material to form char with emission of nitrogen volatiles from SPUA, leading to the formation of expanding char. The morphologic structures of crusts of the formed chars were observed by scanning electron microscopy, confirming the synergistic effect between SPUA and DGTH. POLYM. ENG. SCI., 48:116–123, 2008. © 2007 Society of Plastics Engineers