Preparation of β‐SiCw/BDM/DBA composites with excellent comprehensive properties

Functionalized β‐SiC whiskers (β‐SiCw) are employed to prepare β‐SiCw/N,N′‐4, 4′‐bimaleimide diphenyl methane/diallylbisphenol A (β‐SiCw/BDM/DBA) composites via powder blending‐casting method. The thermal conductive coefficient of the β‐SiCw/BDM/DBA composites is 0.994 W/mK with 40 wt% functionalized β‐SiCw, five times higher than that of pure BDM/DBA. The mechanical properties of the β‐SiCw/BDM/DBA composites are optimal with 10 wt% functionalized β‐SiCw. Both thermal resistance and dielectric constant are increased with the increasing addition of β‐SiCw. For a given β‐SiCw loading, the surface functionalization of β‐SiCw exhibits a positive effect on the thermal conductivities and mechanical properties of the β‐SiCw/BDM/DBA composites. POLYM. COMPOS., 35:1875–1878, 2014. © 2014 Society of Plastics Engineers     

Low‐Temperature Sintering of β‐Spodumene Ceramics Using Li2O–GeO2 as a Sintering Additive

Low‐temperature sintering of β‐spodumene ceramics with low coefficient of thermal expansion (CTE) was attained using Li₂O–GeO₂ sintering additive. Single‐phase β‐spodumene ceramics could be synthesized by heat treatment at 1000°C using highly pure and fine amorphous silica, α‐alumina, and lithium carbonate powders mixture via the solid‐state reaction route. The mixture was calcined at 950°C, finely pulverized, compacted, and finally sintered with or without the sintering additive at 800°C–1400°C for 2 h. The relative density reached 98% for the sample sintered with 3 mass% Li₂O–GeO₂ additive at 1000°C. Its Young's modulus was 167 GPa and flexural strength was 115 MPa. Its CTE (from R.T. to 800°C) was 0.7 × 10^?6 K^?1 and dielectric constant was 6.8 with loss tangent of 0.9% at 5 MHz. These properties were excellent or comparative compared with those previously reported for the samples sintered at around 1300°C–1400°C via melt‐quenching routes. As a result, β‐spodumene ceramics with single phase and sufficient properties were obtained at about 300°C lower sintering temperature by adding Li₂O–GeO₂ sintering additive via the conventional solid‐state reaction route. These results suggest that β‐spodumene ceramics sintered with Li₂O–GeO₂ sintering additive has a potential use as LTCC for multichip modules.     

Comparison of the effects of phenyl dichlorophosphate modified and unmodified β‐iron(III) oxide hydroxide on the thermal,combustion, and mechanical properties of ethylene–vinyl acetate/magnesium hydroxide composites

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.     

Fabrication and properties of cordierite / anorthite composites

The designed cordierite/anorthite batch compositions were studied to gain the favorable properties of both materials where, cordierite has low thermal expansion coffecient and high strength than anorthite.Low cost starting materials such as sugar beat filter cake and talc carbonate were used in the present study. Examination of the effect of cordierite addition (in the range of 10-25mass-%) on the physical, mechanical, electrical and thermal expansion coefficient properties as well as the phase composition and microstructure for the fabricated cordierite/anorthite composites were carried out. The results reveal that the increase in the cordierite content up to 20 mass-%, improves the sinterability and electrical properties. In addition, it increases the bending strength, hardness and decreases the thermal expansion coffecient. However, further increase in the cordierite content up to 25 mass% has negative influence on the physical, electrical and mechanical properties of the cordierite/anorthite composites.     

Sintering and properties of borosilicate glass/Li-Na-K-feldspar composites for electronic applications

Glass/ceramic composites are considered as one of the most important materials for electronic applications. In the present work, an attempt for using Li-Na-K containing feldspar in addition to borosilicate glass to fabricate glass/ceramic composites having good properties was conducted. Firstly, the glass frit was prepared and grinded by high energy ball mill to get nano powder. Then, five designed batches of glass/feldspar composites containing 10, 20, 30, 40 and 50 wt% feldspar were mixed, pressed and sintered at 850 °C. Bulk density and apparent porosity of sintered specimens were determined by Archimedes method. Identification of the formed phases was examined by X-ray diffraction (XRD) analysis. Microstructure of sintered bodies was examined by scanning electron microscope. Microhardness of sintered samples was determined using Vickers indentation technique whereas the fracture toughness was determined by Indentation Fracture (IF) method. The dielectric constant of sintered composites was measured at 1 MHz. The thermal expansion coefficient (TEC) was also measured in the temperature range from room temperature to 1000 °C. The results revealed that Li-Na-K feldspar and borosilicate glass were successfully used to fabricate composites with good electrical properties and thermal expansion suitable for electronic applications. The inhibition of cristobalite amount and the formation of beta spodumene in addition to the quartz were responsible for the improvement of the electrical and thermal properties. The formed amount of beta spodumene was the ideal amount after which the higher amount can cause crack in the body due to the volume change occurred by the differences in thermal expansion of alpha and beta spodumene.     

钙长石／玻璃复合材料的制备和性能研究

采用电子陶瓷工艺制备了一系列钙长石／玻璃复合材料,并对复合材料进行X射线分析、扫描电镜观察和性能测试。结果表明：复合材料的介电常数、热膨胀系数随钙长石含量的增加而增加,而介电损耗和抗折强度随钙长石含量的增加而减小。钙长石含量大于50wt％的复合材料中α-石英和方石英的析出增加了材料的热膨胀系数,但对材料的介电性能影响不大。所制备的复合材料具有低的介电常数（5．4～6．1）、低的介电损耗（0．11％～0．41％）、低的热膨胀系数（4．3×10^-6～6．1×10^-6／℃）和低的烧结温度（≤900℃）,有望用于电子封装领域。     

Preparation of Nano‐Sized Copper β‐Resorcylate (β‐Cu) and its Excellent Catalytic Activity for the Thermal Decomposition of Ammonium Perchlorate

Copper β‐resorcylate (cupric 2,4‐dihydroxy‐benzoate, β‐Cu) nanoparticles were prepared at a large‐scale via a facile wet mechanical grinding method and vacuum freeze‐drying process. The as‐prepared β‐Cu nanoparticles were characterized by powder X‐ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Fourier‐transform infrared spectroscopy (FT‐IR). The results revealed that the nano‐sized β‐Cu is of semi‐spherical shape and of homogeneous distribution, with a fairly uniform size of 100 nm. The formation mechanism of β‐Cu nanoparticles in the whole process was discussed in detail. Furthermore, the catalytic properties of as‐obtained β‐Cu were investigated. The TG/DSC study showed that nano‐sized β‐Cu could be a promising additive for accelerating the thermal decomposition of ammonium perchlorate (AP).     

First principles investigation on mechanical and thermal properties of α‐ and β‐YAlB4 ultra‐high temperature ceramics

Ultra‐high temperature ceramics (UHTCs) exhibit a unique combination of excellent properties that makes them promising candidates for applications in extreme environments. Various UHTCs are needed due to diverse harsh conditions that UHTCs are faced with in different applications. Due to structural similarity to ZrB₂, possible high melting point and possible protective oxide scale formed in oxygen rich and water vapor environments, REAlB₄ (RE: rare‐earth) is suggested a good candidate for UHTCs. In the present work, temperature‐dependent mechanical and thermal properties of both α‐YAlB₄ (YCrB₄ type, space group Pbam) and β‐YAlB₄ (ThMoB₄ type, space group Cmmm) were investigated by first principles calculations in combination with quasi‐harmonic approach. Due to the structural similarity between α‐YAlB₄ and β‐YAlB₄, their properties are very similar to each other, which are approximately transverse isotropic with properties in (001) plane being almost the same and differing from properties out of (001) plane. The results reveal that resistance to normal strain in (001) plane (~460 GPa) is higher than that along [001] direction (~320 GPa) and thermal expansion in (001) plane (~10 × 10^?6 K^?1) is lower than that along [001] direction (~17 × 10^?6 K^?1), which is because the stiff boron networks are parallel to (001) plane. The average thermal expansion coefficient is around 12 × 10^?6 K^?1, which is fairly high among UHTCs and compatible with metallic frameworks. The combination of high thermal expansion coefficient and protective oxidation scale forming ability suggest that REAlB₄ is promising for practical applications not only as high‐temperature structural ceramic but also as oxidation resistant coating for alloys.     

Green composites of poly(3‐hydroxybutyrate) and curaua fibers: Morphology and physical,thermal, and mechanical properties

In this article, we report the morphology and thermal, mechanical and physical properties of poly(3‐hydroxybutyrate) (PHB)/curaua composites containing triethyl citrate (TEC) as the plasticizer. The composites were prepared by mechanical mixing using pristine and chemically treated fibers (10 wt %) and TEC (30 wt %) and characterized by differential scanning calorimetry, dynamic mechanical analysis, X‐ray diffraction, small angle X‐ray scattering, polarized optical microscopy, scanning electron microscopy, tensile tests, impact resistance test, thermodilatometry, and thermal conductivity measurements. The curaua fibers acted as nucleating agent and strongly influenced the morphology of the crystalline phase of PHB, increasing the lamella thickness, decreasing the crystal size and inducing spherulite–axialite transition. These characteristics of the PHB crystalline phase determined all the properties of the composites. The tensile properties of the composites were comparable with those of neat PHB, while the impact resistance of composites was comparable with that of plasticized PHB. The higher heat capacity and thermal expansion coefficient and the lower thermal conductivity of the composites compared with neat PHB reflect the morphological changes in the PHB crystalline phase. The strategy of developing a green polymeric material from ecofriendly components exhibiting a good balance of properties by combining curaua fibers, TEC, and PHB was successful. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017 , 134, 44676.     

Melting and crystallization behaviors,morphology, and mechanical properties of β‐polypropylene/polypropylene‐graft‐maleic anhydride/calcium sulfate whisker composites

The melting and crystallization behaviors, morphology, and mechanical properties of polypropylene (PP)/surface‐treated calcium sulfate (CaSO₄) whisker (T‐CSW), β‐PP/T‐CSW, and β‐PP/polypropylene‐graft‐maleic anhydride (PP‐g‐MAH)/T‐CSW composites had been investigated via differential scanning calorimetry (DSC), wide angle X‐ray diffraction (WAXD), polarized light microscopy (PLM), scanning electron microscopy (SEM), and mechanical tests. We found that T‐CSW was an α‐nucleating agent and increased the crystallization temperatures of PP, but PP‐g‐MAH and high loadings of T‐CSW had weakly negative effects on the crystallization rates of PP. The T‐CSW restrained the formation of β‐spherulites, and the spherulitic size decreased in the composites. PP‐g‐MAH improved the compatibility and adhesion between T‐CSW and the matrix. The notched impact strength was improved, and the tensile strength was enhanced at low levels of T‐CSW, while the flexural modulus was weakened for β‐PP/T‐CSW and β‐PP/PP‐g‐MAH/T‐CSW composites versus PP/T‐CSW composites. POLYM. COMPOS., 37:2121–2132, 2016. © 2015 Society of Plastics Engineers     

Correlation between the fracture toughness and β‐crystal fraction in a β‐nucleated propylene‐based propylene–ethylene random copolymer

Propylene‐based propylene–ethylene random copolymer (PPR) has been widely used in the production of hot‐water pipes. To further improve its toughness and thermal resistance, β‐nucleating agents (β‐NAs) are frequently incorporated. In this study, PPR containing 5.6 mol % ethylene units was modified by two kinds of β‐NAs, that is, calcium pimelate and N,N′‐dicyclohexylterephthalamide. The notched Izod impact strength of PPR increased with the addition of the β‐NAs. Drastically different toughening effects were found between the two β‐NAs. The structure of PPR with and without a β‐NA was investigated by calorimetry, X‐ray diffraction, and thermomechanical analysis. The results indicated that the relative fraction of β crystals (k_β) in the injection‐molded specimens was determined by the type and content of β‐NA. The relationship between k_β and the impact toughness was summarized. A critical value for k_β (0.68) was identified for the brittle–ductile transition of PPR. PPR with β‐NA having a k_β greater than 0.68 displayed a higher impact strength than the other mixtures. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 42930.     

Improved conductivity and thermal stability by the formation of a charge‐transfer complex in β‐nucleation‐agent‐nucleated and MWCNT‐filled iPP composites

In this study, the influence of β‐nucleation agent (β‐NA) on the morphology and properties of multi‐walled carbon nanotube (MWCNT) filled isotactic polypropylene (iPP) composites was explored in details. The results show that the incorporation of β‐NA has promoted the dispersion of MWCNT in the iPP matrix, which is profitable for improving the thermal stability and conductivity properties of MWCNT‐iPP composites. Besides, the 0.05 wt % β‐NA nucleated samples exhibit higher impact toughness than that of un‐β‐NA‐nucleated ones. Further SEM observations show that the morphology of MWCNT changes from large agglomerations to small clusters with doping of β‐NA. The main reason is that the incorporation of β‐NA (TMB‐5) in MWCNT filled iPP matrix has led to the formation of a charge‐transfer complex. Some of these clusters act as nucleation sites for inducing crystallization of α spherulites, which have a compete growth with β‐NA induced β crystals. Meanwhile, other clusters exist in the inter‐lamella amorphous phase of β crystals, some of them even combine two adjacent β spherulites. Accordingly, a large conductive network comes into being. Based on the investigated results, a mechanism model is proposed. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Thermal characterization of carbon‐nanofiber‐reinforced tetraglycidyl‐4,4′‐diaminodiphenylmethane/4,4′‐diaminodiphenylsulfone epoxy composites

The thermal properties of carbon nanofibers (CNF)/epoxy composites, composed of tetraglycidyl‐4,4′‐diaminodiphenylmethane (TGDDM) resin and 4,4′‐diaminodiphenylsulfone (DDS) as a curing agent, were investigated with differential scanning calorimetry (DSC), thermogravimetric analysis, and dynamic mechanical thermal analysis. DSC results showed that the presence of CNF had no pronounced influence on the heat of the cure reaction. However, the incorporation of CNF slightly improved the thermal stability of the epoxy. Furthermore, the storage modulus of the TGDDM/DDS epoxy was significantly enhanced, whereas the glass‐transition temperature was not significantly affected, upon the incorporation of CNFs. The storage modulus of 5 wt % CNF/epoxy composites at 25°C was increased by 35% in comparison with that of the pure epoxy. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 295–298, 2006     

Mechanical,thermal and electrical properties of multi‐walled carbon nanotube/aluminium nitride/polyetherimide nanocomposites

A series of polyimide‐based nanocomposites containing polyimide‐grafted multi‐walled carbon nanotubes (PI‐g MWCNTs) and silane‐modified ceramic (aluminium nitride (AlN)) were prepared. The mechanical, thermal and electrical properties of hybrid PI‐g MWCNT/AlN/polyetherimide nanocomposites were investigated. After polyimide grafting modification, the PI‐g MWCNTs showed good dispersion and wettability in the polyetherimide matrix and imparted excellent mechanical, electrical and thermal properties. The utilization of the hybrid filler was found to be effective in increasing the thermal conductivity of the composites due to the enhanced connectivity due to the high‐aspect‐ratio MWCNT filler. The use of spherical AlN filler and PI‐g MWCNT filler resulted in composite materials with enhanced thermal conductivity and low coefficient of thermal expansion. Results indicated that the hybrid PI‐g MWCNT and AlN fillers incorporated into the polyetherimide matrix enhanced significantly the thermal stability, thermal conductivity and mechanical properties of the matrix. Copyright © 2012 Society of Chemical Industry     

Thermal and flammability performance of polypropylene composites containing melamine and melamine phosphate‐modified α‐type zirconium phosphates

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.     

Investigation on β‐polypropylene/PP‐g‐MAH/ surface‐treated calcium carbonate composites

β‐Polypropylene composites containing calcium carbonate treated by titanate coupling agent (T‐CaCO₃) and maleic anhydride grafted PP (PP‐g‐MAH) were prepared by melt compounding. The crystallization, morphology and mechanical properties of the composites were investigated by means of differential scanning calorimetry, wide‐angle X‐ray diffraction, polarized light microscopy, scanning electron microscopy and mechanical tests. It is found that both T‐CaCO₃ and NT‐C are able to induce the formation of β‐phase, and NT‐C greatly increases the β content and decreases the spherulitic size of PP. PP‐g‐MAH facilitates the formation of β‐form PP and improves the compatibility between T‐CaCO₃ and PP. Izod notched impact strength of β‐PP/T‐CaCO₃ composite is higher than that of PP/T‐CaCO₃ composite, indicating the synergistic toughening effect of T‐CaCO₃ and β‐PP. Incorporation of PP‐g‐MAH into β‐PP/T‐CaCO₃ composite further increases the content of β‐crystal PP and improves the impact strength and tensile strength when T‐CaCO₃ concentration is below 5 wt%. The nonisothermal crystallization kinetics of β‐PP composites is well described by Jeziorny's and Mo's methods. It is found that NT‐C and T‐CaCO₃ accelerate the crystallization rate of PP but the influence of PP‐g‐MAH on crystallization rate of β‐PP composite is marginal. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

Simultaneously improving the toughness,flexural modulus and thermal performance of isotactic polypropylene by α‐β crystalline transition and inorganic whisker reinforcement

Magnesium salt (M‐HOS) whisker and β‐nucleating agent were introduced into polypropylene and their effects on the crystalline structures, morphologies, mechanical properties, and thermal resistance of polypropylene (PP) were investigated. The results of wide angle X‐ray diffraction (WAXD), differential scanning calorimetry (DSC), and polar optical microscopy (POM) examinations suggested that the presence of the whisker did not cause any negative effect on the occurrence of β‐modification, and β‐phase became absolutely dominant form in β‐nucleated samples. The mechanical and thermal properties tests demonstrated that there is an excellent synergy between the β‐nucleating agent and the whisker. For PP composite containing 0.1 wt% of the β‐nucleating agent and 10 wt% of the whiskers, the Izod notched impact strength, elongation at break, flexural modulus, and heat deflection temperature were increased by 108, 194, 31, and 40%, respectively, compared with those of neat PP. By combining the toughening effect of α–β transition with the reinforcing effect of the whisker, simultaneous improvement in toughness, flexural modulus, and thermal performance of PP was successfully achieved. POLYM. ENG. SCI., 2009. © 2009 Society of Plastics Engineers     

Comparative study on the crystallization behavior of β‐isotactic polypropylene nucleated with different β‐nucleation agents —effects of thermal conditions

In this study, the crystallization behavior of the β‐isotactic polypropylene (β‐iPP) samples nucleated by a rare earth based β‐nucleating agent (β‐NA) WBG‐II and a metal salts compound β‐NA NAB83 (denoted as WPP and NPP, respectively) under different cooling conditions were comparatively investigated. The thermal conditions such as the cooling rate, isothermal crystallization temperature, isothermal crystallization time, and the subsequent cooling to room temperature. The results of WAXD, SEM, and nonisothermal crystallization reveal that under the same processing conditions, the crystallite size of NPP is smaller, which arrange more compactly as compared with WPP. Meanwhile, NPP has shorter crystallization rate and higher β‐nucleation selectivity, but WPP can crystallization at wider temperature range. The results of isothermal crystallization showed that NPP has higher selectivity and higher β‐nucleation efficiency, which favors the formation of high proportion of β‐phase at the isothermal crystallization temperature of 110–130°C with and without subsequent cooling; WPP has lower selectivity, which can only induce high content of β‐phase under isothermal crystallization without subsequent cooling to 25°C. In tuning the crystallization behavior and the properties of β‐PP, the joint influence of the efficiency and selectivity of the β‐NA, and the thermal conditions should be taken into consideration. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40115.     

The β‐δ‐Phase Transition and Thermal Expansion of Octahydro‐1,3,5,7‐Tetranitro‐1,3,5,7‐Tetrazocine

Phase behavior of octahydro‐1,3,5,7‐tetranitro‐1,3,5,7‐tetrazocine (HMX) is investigated by X‐ray powder diffraction (XRD). The XRD patterns at elevated temperature show that there is a co‐existing temperature range of β‐ and δ‐phase during the phase transition process. Additionally, mechanical forces can catalyze the conversion from δ‐ back to β‐phase. Based on the diffraction patterns of β‐ and δ‐phase at different temperatures, we calculate the coefficients of thermal expansion by Rietveld refinement. For β‐HMX, the linear coefficients of thermal expansion of a‐axis and b‐axis are about 1.37×10⁻⁵ and 1.25×10⁻⁴ °C⁻¹. A slight decrease in c‐axis with temperature is also observed, and the value is about −0.63×10⁻⁵ °C⁻¹. The volume coefficient of thermal expansion is about 1.60×10⁻⁴ °C⁻¹, with a 2.2% change from 30 to 170 °C. For δ‐HMX, the linear coefficients of thermal expansion of a‐axis and c‐axis are found to be 5.39×10⁻⁵ and 2.38×10⁻⁵ °C⁻¹, respectively. The volume coefficient of thermal expansion is about 1.33×10⁻⁴ °C⁻¹, with a 2.6% change from 30 to 230 °C. The results indicate that β‐HMX has a similar volume coefficient of thermal expansion compared with δ‐HMX, and there is about 10.5% expansion from β‐HMX at 30 °C to δ‐HMX at 230 °C, of which about 7% may be attributed to the reconstructive transition.     

Evaluation of nonconventional additives as fire retardants on polyamide 6,6: Phosphorous‐based master batch, α‐zirconium dihydrogen phosphate,and β‐cyclodextrin based nanosponges

The influence of new types of additives, such as halogen‐ and antimony‐free flame‐retardant master batches based on phosphorus, α‐zirconium dihydrogen phosphate, and β‐cyclodextrin nanosponges, on the flame retardancy of polyamide 6,6 (PA6,6) by means of cone calorimetry and limiting oxygen index (LOI) tests was investigated. A significant decrease of the heat release rate, depending by the type of additive used, was observed. Furthermore, with the consideration that the life safety during the fire could be improved by a decrease in the fire hazard, a decrease in the quantity of the smoke and its toxicity, depending also on the type of additive, was revealed. With regard to the LOI test, neat PA6,6 showed a slight increase in the LOI value in comparison with the PA6,6 composites. However, all of the PA6,6/composites showed a slower burning velocity and antidripping effects at oxygen concentrations corresponding to the LOI value. To understand the flame‐retardancy mechanism of these novel PA6,6 composites, we thoroughly investigated their thermal decomposition behavior and microstructure/elemental analysis by scanning electron microscopy/energy‐dispersive X‐ray spectroscopy. Furthermore, the combustion behavior of these novel PA6,6 composites was compared with that of conventional nanofillers (e.g., modified montmorillonite clay and carbon nanotubes). © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012