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Plastic is a revolutionary material. However, pollution caused by plastic damages the environment, human health, and economy of different countries. It is important to find the new methods for recycling and reusing plastic materials. In this present study, plastic waste coming from high‐density polyethylene (HDPE) cups (called HDPEr in the following) are used together with virgin cork for production of composite materials. Different fractions of virgin cork with HDPEr are tested and allow to obtain successfully composite materials. The properties of HDPEr and composite are compared. The morphology of elaborated composite is studied by scanning electron microscope (SEM). The thermal properties are investigated by thermogravimetric analysis (TGA) analysis; the flammability study is performed using a cone calorimeter. Moreover, the mechanical properties of the samples stored under different conditions are studied by tensile strength experiments. The results show that the cork content has an effect on the mechanical and thermal properties. The feasibility of the composites based on cork and HDPEr wastes opens the way of reusing of these wastes. The formulation of HDPEr composites must be optimized by adding a flame retardant and a coupling agent. [ABSTRACT FROM AUTHOR]

This research studies natural rubber (NR) composite blends prepared with recycled polyethylene (PE), polyurethane waste (PU), silica (SiO2), and aluminum trihydroxide (ATH) under the proper mixing conditions using an internal mixer and a two-roll mill. The mechanical, impact, dynamic mechanical, and thermal properties, together with flammability, were investigated. NR/PU composites filled with a specific SiO2/ATH concentration resulted in excellent flame-retardant properties without using PE. Adding PE causes poor flammability, while using PU and SiO2 prevents flame extensibility of the composites. In addition, SiO2 and ATH synergistically improved both mechanical and dynamical mechanical properties. This is attributed to the reinforcement of SiO2 particles inside the matrix, whereas the ATH releases water as a flame retardant. The V-0 composites tested with UL-94 showed acceptable heat resistance, strength, and durability, making them suitable for interior and exterior applications in buildings without the lightweight requirement. [ABSTRACT FROM AUTHOR]

This study aims to increase the flame retardancy of epoxy‐based composites by using various flame retardants together with colemanite filler (CLM), which is a very mineral‐rich boron type. As a flame retardant, aluminum hydroxide (Al(OH)3) and boron‐containing compounds: borax (BRX) and natural minerals (tincal (TNC) and colemanite (CLM)), as well as barium metaborate (BaMB) synthesized by us were used. Scanning electron microscopy (SEM), x‐ray powder diffraction (XRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), contact angle (CA), and particle size analysis were used to characterize the composites and additives. All boron compounds increased the thermal stability of the composites. Except for the ER/CLM‐BaMB composite, other composites' surface contact angles were over 90°. In terms of both combustion and thermal properties, the best CLM‐BaMB‐Al(OH)3‐TNC ratio was determined as 15:5:15:15. The tensile strength, self‐extinguishing time, estimated and experimental Limited Oxygen Index (LOI) values for this composite were determined as 96 MPa, 65 s, 29.6%, and 25%, respectively. In addition, ANOVA was applied to determine the effect of hybrid filler type and different weight ratios on the mechanical properties of composites. [ABSTRACT FROM AUTHOR]

Natural fiber composites are not suitable for use in industries due to their flammability and low thermal resistance. Inorganic metal‐based fillers are known to enhance the flammability and thermal resistance of composites, while the thermal and fire‐retardant properties of organic fillers are not commonly known. This study evaluated the mechanical, thermal, and flammability properties of Ceiba petandra fiber (CPF)‐reinforced composites, which were added with snail powder (SP). To study the thermal resistance of the composite, a dynamic mechanical analyzer (DMA) and thermogravimetric analysis (TGA) were applied. SP Filler concentration increased the composite's tensile strength and thermal resistance. DMA test results showed the same trend as the composite's density value. The flame rate parameters of the composite, including the percentage of char yield and the limitation index oxygen (LOI), rose as the SP filler increased. However, the flame rate of the composite dropped because SP filler inhibited the movement of oxygen, combustible gas, and polyester degradation products. The addition of organic fillers in natural fiber composites promises better flammability and thermal resistance. [ABSTRACT FROM AUTHOR]

This study focuses on examining the influence of bast fibers on the flammability and thermal properties of the polylactide matrix (PLA). For this purpose, Urtica dioica and Vitis vinifera fibers were subjected to two types of modifications: mercerization in NaOH solution (M1 route) and encapsulation in an organic PLA solution (M2 route). In a further step, PLA composites containing 5, 10, and 15 wt% of unmodified and chemically treated fibers were obtained. The results of the tests show that only biocomposites containing mercerized fibers had a nearly 20% reduced flammability compared to that of PLA. Moreover, the biofiller obtained in this way belongs to the group of flame retardants that generate char residue during combustion, which was also confirmed by TGA tests. The M2 modification route allowed to achieve higher mass viscosity than the addition of unmodified and M1-modified fibers. The reason is that fibers additionally encapsulated in a polymer layer impede the mobility of the chain segments. The inferior homogenization of the M2-modified fibers in the PLA matrix translated into a longer combustion time and only a 15% reduction in flammability. [ABSTRACT FROM AUTHOR]

Biomass aerogels have attracted wide attention due to their excellent thermal insulation properties, but their low mechanical strength and high susceptibility to combustion limit their application. To address these limitations, a novel composite aerogel was prepared by combining chitosan aerogel (CS) and hydroxyapatite nanowires (HAP) via phytic acid (PA) cross‐linking and freeze‐drying. It was found that the maximum compressive strength and modulus of CS/HAP aerogel were 1.13 and 0.67 MPa, respectively. The minimum thermal conductivity of CS/HAP(0.5) composite aerogel was 0.03921 W m−1 K−1, indicating its good thermal insulating property. Moreover, the CS/HAP composite aerogel also showed excellent flame‐retardant properties. The heat release rate (HRR) and total heat release from combustion (THR) were significantly lower than those of the CS aerogel, with values of 35.2 kW m−2 and 3.7 MJ m−2, respectively, compared to 169.6 kW m−2 and 5.4 MJ m−2. The total smoke release (TSR) was also at a low level, reaches 0.4 m2 m−2. Highlights: Propose a novel chitosan aerogel composited with inorganic nano‐reinforced HAP.High mechanical strength of CS/HAP composite aerogel are illustrated.Exhibit excellent thermal insulation performance of CS/HAP aerogel.HAP and PA largely improves the flame retardancy of the chitosan aerogel. [ABSTRACT FROM AUTHOR]

Polymers are widely employed in many areas, e.g. transport, packaging, electronic devices, etcetera. Among them, acrylonitrile–butadiene–styrene (ABS) is one of the most employed polymers due to its mechanical properties, its ease to mechanize and recyclability. Nevertheless, according to the fire properties, ABS behaviour is usually worse than other polymers, therefore, they have to be upgraded with flame retardant additives. To characterize the fire behaviour of a certain material is necessary to address several typology of tests, providing relevant properties such as thermal conductivity, flammability and heat released. However, researchers may not always be able to run all tests due to the lack of apparatus or samples. Therefore, it is necessary to seek bibliographic sources. As one might expect, for a given material, the property values should be similar, regardless of who performs the test. However, sometimes slightly different results are obtained, which may be due to different causes, such as differences in test set-up and in material composition/manufacture. These differences in properties may lead researcher to doubt which data to use. This paper presents the results of different types of tests using neat ABS polymer. Additionally, these results are compared with the data from literature, discussing the similarities/differences and offering a more comprehensive characterization of ABS. The laboratory techniques included in this work are: thermogravimetric analysis, differential scanning calorimetry, laser flash analysis, smoke density, cone calorimeter, fire propagation and flammability. [ABSTRACT FROM AUTHOR]

This study focuses on examining the influence of bast fibers on the flammability and thermal properties of the polylactide matrix (PLA). For this purpose, Urtica dioica and Vitis vinifera fibers were subjected to two types of modifications: mercerization in NaOH solution (M1 route) and encapsulation in an organic PLA solution (M2 route). In a further step, PLA composites containing 5, 10, and 15 wt% of unmodified and chemically treated fibers were obtained. The results of the tests show that only biocomposites containing mercerized fibers had a nearly 20% reduced flammability compared to that of PLA. Moreover, the biofiller obtained in this way belongs to the group of flame retardants that generate char residue during combustion, which was also confirmed by TGA tests. The M2 modification route allowed to achieve higher mass viscosity than the addition of unmodified and M1-modified fibers. The reason is that fibers additionally encapsulated in a polymer layer impede the mobility of the chain segments. The inferior homogenization of the M2-modified fibers in the PLA matrix translated into a longer combustion time and only a 15% reduction in flammability.

The cellulose (Cel)-polyvinyl alcohol (PVA)-sodium alginate (SA) composite aerogels are prepared by adding PVA and SA to the Cel suspension, followed by freeze-drying. The structure and properties of Cel-PVA-SA composite aerogels are determined by FT-IR, scanning electron microscopy, thermogravimetric analysis, limiting oxygen index method and cone calorimetry. The results reveal that sodium alginate is uniformly distributed within the aerogels. The as-synthesized composite aerogels possess excellent compressive resilience properties. In addition, the addition of sodium alginate significantly reduces the flammability of cellulose. Therefore, this study provides a simple method to prepare green flame-retardant Cel-PVA composite aerogels materials, and the aerogels demonstrate excellent potential for application in construction materials. [ABSTRACT FROM AUTHOR]

Abstract In this study, walnut shell particles obtained through the grinding of walnut shells were used as a reinforcing material and pumice powder as a filler for developing epoxy-based composites characterized by reduced flammability. Thermogravimetric analysis (TGA), Differential scanning calorimetry (DSC), and Underwriters Laboratories (UL)-94 vertical tests were carried out for evaluating the effectiveness of these pumice powder treatments. Under the UL-94 vertical test, composites (S1, S2, S3, S4, S5 and S6) with 20% pumice powder (i.e., by mass content of walnut particles were not self-extinguished, and could not be classified. S7 and S8 composites (40wt% and 50%) assigned a V-2 rating, which was the least flammable composite However, the mechanical tensile tests showed that the pumice powder treated composites increased their tensile strength. The morphological analysis showed an enhancement of the interfacial adhesion of the composites achieved by pumice powder.

This study presents the preparation and flammability characteristics of polymeric composites based on the epoxy resin Epidian® 601. The triethylenetetramine (TETA) and commercial curing agents based on polyamines (IDA and PAC) were used as crosslinking compounds. Moreover, two flame retardant compounds were added to this composition, the commercial Fire Retardant (FR) and triphenyl phosphate (TP). The chemical structure of the composites and the course of curing processes were confirmed by the ATR/FT-IR (Attenuated Total Reflection–Fourier Transform Infrared) analysis. The influence of different amounts of FR or TP on the flammability and thermal resistance was discussed in detail. After the flammability test the samples were also studied to assess their thermal destruction. In addition, the composites were subjected to the swelling tests, solvent resistance, and microscopic observations. The DSC curves revealed that all materials were characterized by good thermal properties. All materials were temperature resistant up to 300 °C. Furthermore, the measurements of the hardness of the composite demonstrated that the material EP601 + TETA + 10 %FR is the hardest. The addition of FR and RP influenced the flammability of the composites increasing the thermal resistance. The ageing tests in methanol, acetone, hydrochloric acid, and potassium hydroxide were also carried out. [ABSTRACT FROM AUTHOR]

Poly(lactic acid) (PLA) is derived from crops, and has a broad application prospect in electronics and electrical, automotive industries due to its biodegradability and good physical and mechanical properties. However, PLA's flammability and serious melt dripping cannot meet the requirements of terminal products, thus limiting its application. Over the past decade, much research on flame retardant PLA has emerged. This paper reviews the development of PLA flame retardants in recent years, focusing on phosphorus‐based, phosphorus–nitrogen‐based, bio‐based, nanoparticles, intumescent flame retardants, and their combinations. Besides that, the efficiency of flame retardant and its loading on the thermal and mechanical properties of PLA is also thoroughly reviewed. Finally, the future development of flame‐retardant PLA is briefly summarized and prospected. [ABSTRACT FROM AUTHOR]

Polybutylene terephthalate (PBT) composites were prepared with 1.0 phr synthetic wollastonite nanofibers (SWN), natural wollastonite (NW) and graphene oxide (GO) to study the effect of different fillers on mechanical, thermal, tribological, and flammability properties. The properties of PBT composites are related to the size, structure, and interfacial adhesion of the fillers in PBT matrix. PBT/SWN demonstrated the highest tensile strength and Young's modulus (6% and 9% increment), followed by PBT/NW (1.3% and 7% increment) and PBT/GO (2% decrement and 4% increment). PBT/SWN gave the highest degradation temperature (409°C), followed by PBT/GO (404.7°C). The maximum enhancement in wear resistance (73%) by PBT/SWN and anti‐friction performance (26%) by PBT/GO evinced the excellent load‐bearing ability of SWN and the great lubricating effect of GO. PBT/NW had the lowest peak heat release rate, smoke, and carbon dioxide production rate. This study shows that PBT composites have great potential in different automotive applications. [ABSTRACT FROM AUTHOR]

This study investigated suspending two fire retardants in sugar-cane bagasse plies used for manufacturing natural fibre reinforced composites. Sugar-cane bagasse was alkali treated, blended with either APP (Ammonium Polyphosphate) or ATH (Aluminium Hydroxide), pressed and dried to form plies. Composites were manufactured using a light resin transfer moulding process with epoxy resin. Composites manufactured with fire retardant suspended plies were compared to composites with plies layered with equivalent amounts of fire retardants. The composites were characterised using thermogravimetric analysis (TGA) for thermal stability and char yield, isotropic hot disc method for thermal properties, and cone calorimeter for studying ignition and flammability. Plies suspended with APP had the highest char yield of 58% (in nitrogen), reducing to 26% in the composite form, with degradation driven by the epoxy matrix. The composite layered with ATH had the latest ignition times of 118 s when tested with a radiant heat flux of 35 kW/m2. The composite layered with APP displayed the lowest average heat release rate (179.7k W/m2), peak heat release rate (305.6k W/m2), and total heat released (135.5 MJ/kg). When assessing the fire growth, the composite layered with APP was again favourable. While the layering yielded more favourable results than the suspension of the same retardants, this study showed that a rudimentary process was able to suspend enough retardants to improve the behaviour of the resulting composites in a fire scenario. [ABSTRACT FROM AUTHOR]

Despite a recent sustained preoccupation for developing biobased epoxies with enhanced applicability, such products have not been widely accepted for industry because of their inferior characteristics compared to classic petroleum-based epoxy thermosets. Therefore, significant effort is being made to improve the flame retardance of the most commonly used epoxies, such as diglycidyl ether-based bisphenol A (DGEBA), bisphenol F (DGEBF), novalac epoxy, and others, while continuously avoiding the use of hazardous halogen-containing flame retardants. Herein, a phosphorus-containing bisphenol, bis(4-(((4-hydroxyphenyl)amino)(6-oxido-6H-dibenzo[c,e][1,2]oxaphosphinin-6-yl)methyl)phenyl) phenylphosphonate (BPH), was synthesized by reacting bis(4-formylphenyl)phenylphosphonate with 4-hydroxybenzaldehyde followed by the addition of 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) to the resulting azomethine groups. Environmentally friendly epoxy-based polymer thermosets were prepared by using epoxy resin as polymer matrix and a mixture of BPH and 4,4′-diaminodiphenylsulfone (DDS) as hardeners. A hyperbranched phthalocyanine polymer (HPc) and BaTiO3 nanoparticles were incorporated into epoxy resin to improve the characteristics of the final products. The structure and morphology of epoxy thermosets were evaluated by infrared spectroscopy and scanning electron microscopy (SEM), while the flammability characteristics were evaluated by microscale combustion calorimetry. Thermal properties were determined by thermogravimetric analysis and differential scanning calorimetry. The surface morphology of the char residues obtained by pyrolysis was studied by SEM analysis. [ABSTRACT FROM AUTHOR]

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• Tannic acid is neither a good flame retardant nor a highly swelling material. • TA combined with CLS reduces flammability of biocomposite by 30 % compared to PLA. • Mixing of TA with CLS in melt doesn't allow for PHRR reduction of more than 20 %. The purpose of this study was to determine the quantitative and qualitative effects of the form of natural phenolic compounds (NPCs) on the decomposition of polylactide (PLA) under different measurement conditions. For this purpose, thermogravimetry analysis (TGA), differential scanning calorimetry (DSC), and pyrolysis-combustion flow calorimetry (PCFC) analyses were carried out not only on individual raw materials like calcium lignosulfonate (BX), tannic acid (TA), BX chemically modified with TA (BMT), but also on PLA/BX, PLA/TA, and PLA/BMT composites with 3, 6, and 9 wt.% of filler. Moreover, the work checked whether to obtain satisfactory results it is necessary to carry out chemical modification lasting many hours, or whether simple physical mixing of ingredients (TABX) is enough, e.g. in proportions 1:2, 2:4, 3:6. The results of these analyses showed that TA is neither a good flame retardant nor a highly swelling material, but when combined with BX physically or chemically, it can produce an interesting synergistic effect. This work proves that chemically obtained BMT hybrid material allows to reduce flammability by 30 % compared to PLA which cannot be achieved by physically mixing these components in a polymer melt. On the other hand, the addition of TABX is sufficient to achieve a good thermal stabilization effect under processing conditions. [Display omitted] [ABSTRACT FROM AUTHOR]

In this article, bamboo nonwoven fabric (BF) is introduced as reinforcement into the vinyl ester (VE) matrix for the manufacturing of BF/VE composites through Vacuum Assisted Resin Transfer Mold process. Eco-friendly (NaHCO3) and other common treatments (NaOH and Silane) are applied to BF to modify the surface chemistry, thereby improving the mechanical strength (tensile modulus 10(NHTB), 11(NCTB) and 11% (SiTB); flexural modulus 11(NHTB) and 90% (SiTB) and impact strength 23% (SiTB)) and thermal properties. Besides, the three flame retardants (FRs) (chitosan (CS), ammonium polyphosphate (APP), and zinc borate) are incorporated with various percentages (3 and 6) for the improvement of flame retardancy of the BF composites and the experiments are proceeded by Taguchi L9 orthogonal array (OA) through the layup method. The nature of pure and modified BF is analyzed using Fourier transform infrared spectroscopy, x-ray diffraction and scanning electron microscopy exhibited the removal of the constituents and formation of reactive sites, etc. The effect of treatment on the thermal and flame retardant properties is analyzed by thermogravimetric analysis, horizontal burning test, and microcalorimeter, respectively. The thermal stability, burning rate, and peak heat release rate were significantly changed than that of pure BF composites. [ABSTRACT FROM AUTHOR]

In this article, bamboo nonwoven fabric (BF) is introduced as reinforcement into the vinyl ester (VE) matrix for the manufacturing of BF/VE composites through Vacuum Assisted Resin Transfer Mold process. Eco-friendly (NaHCO3) and other common treatments (NaOH and Silane) are applied to BF to modify the surface chemistry, thereby improving the mechanical strength (tensile modulus 10(NHTB), 11(NCTB) and 11% (SiTB); flexural modulus 11(NHTB) and 90% (SiTB) and impact strength 23% (SiTB)) and thermal properties. Besides, the three flame retardants (FRs) (chitosan (CS), ammonium polyphosphate (APP) and zinc borate) are incorporated with various percentages (3 and 6) for the improvement of flame retardancy of the BF composites and the experiments are proceeded by Taguchi L9 orthogonal array (OA) through the layup method. The nature of pure and modified BF is analyzed using Fourier transform-infrared spectroscopy, x-ray diffraction and scanning electron microscopy exhibited the removal of the constituents and formation of reactive sites, etc. The effect of treatment on the thermal and flame retardant properties is analyzed by thermogravimetric analysis, horizontal burning test, and microcalorimeter, respectively. The thermal stability, burning rate, and peak heat release rate were significantly changed than that of pure BF composites. [ABSTRACT FROM AUTHOR]

Currently, the issue of natural flammability of unsaturated polyester resin (UPR) severely restrains its application. In this study, polymeric flame retardant poly methyl vinyl di (1-thio-2,6,7-trioxal-1-phosphabicyclo [2.2] octane-4-methoxy) silane (PMVDOS) with P–S–Si-based cage unit was synthesized. The UPR/PMVDOS composites were prepared by adding different ratios of PMVDOS into UPR. The flame-retardant properties and the char layer structure of UPR samples were evaluated via the limiting oxygen index (LOI), vertical burning test, cone calorimeter test, scanning electron microscopy, laser Raman spectroscopy, and X-ray photoelectron spectroscopy. The results showed that UPR/PMVDOS composites reached the UL-94 V-0 rating with the LOI value of 27.8%, and the carbon residue increased from 4.9% for pure UPR to 14.9% when the content of PMVDOS was 18 wt%. The peaks of heat release rate, total heat release, and total smoke production were comparatively reduced. The flame-retardant mechanism of PMVDOS mainly acted on the condensed phase. The surface of the matrix was covered with the polymer containing phosphorous and silicon dioxide particles, preventing the escape of flammable volatiles and isolating the exchange of oxygen and heat, thus, the degradation of the matrix could be inhibited. This research provides a solution to improve the flame retardancy of UPR. [ABSTRACT FROM AUTHOR]

Polybenzoxazine (PBa) composites based on phosphorous-containing bio-based furfurylamine type benzoxazines (D-fu) and bisphenol-A type benzoxazines (Ba) were developed for flame retardation. The structure of D-fu was analyzed by Fourier transform infrared (FTIR) spectroscopy and 1H-NMR spectroscopy. The curing temperature of Ba/D-fu mixtures was systematically studied by differential scanning calorimetry (DSC). Thermogravimetric analysis (TGA) demonstrated the excellent char formation ability of the PBa composites with the addition of phosphorous-containing D-fu. The flame retardancy of the PBa composite materials was tested by the limited oxygen index (LOI), vertical burning test (UL-94) and cone calorimeter (CONE). The LOI and UL-94 level of PBa/PD-fu-5% reached 34 and V0 rate, respectively. Notably, the incorporation of 5% D-fu into PBa led to a decrease of 21.9% at the peak of the heat-release rate and a mass-loss reduction of 8.0%. Moreover, the fire performance index increased, which demonstrated that the introduction of D-fu can diminish fire occurrence. The role of D-fu in the condensed and gas phases for the fire-resistant mechanism of the PBa matrix was supported by SEM-EDS and TGA/infrared spectrometry (TG-FTIR), respectively. Dynamic mechanical analysis (DMA) revealed that the Tg of PBa flame-retardant composites was around 230 °C. Therefore, PBa composites are promising fire-retardant polymers that can be applied as high-performance functional materials. [ABSTRACT FROM AUTHOR]

Polythiourethane (PTU) has attracted considerable attention in engineering building materials. Here, based on phosphazene nanoparticles (PZS‐1 and PZS‐2) prepared by water‐triggered and ultrasonic self‐assembly method, phosphazene/polythiourethane (PZS/PTU) composites with excellent mechanical strength, high flame retardancy and good transparency was obtained. Then, the comprehensive properties of both composites were evaluated, where PZS‐2 endowed PTU with better overall performance. Due to the good dispersibility of PZS and its strengthed interfacial interaction with PTU matrix, both PZS significantly enhanced mechanical and thermal property of PTU, where the tensile strength and glass transition temperature of PZS/PTU composites reached to 84.34 MPa and 59.94°C respectively. More importantly, compared to pure PTU, the values of peak heat release rate (HRR), total heat release rate (THR), smoke production rate (SPR), and total smoke production (TSP) of composites were decreased by 10.5%, 13.3%, 30.6% and 18.0%, respectively. The limiting oxygen index of composites was improved to 21.39% due to the catalytic carbonization of PZS, the expanded carbon layer and the incombustible gases released during combustion. Meanwhile, the PZS/PTU composite exhibited the high refractive index of 1.6580 and good transparency (not less than 85% at 500 nm). The PZS/PTU composite was promising candidates for optical flame retardant coatings and engineering building materials. [ABSTRACT FROM AUTHOR]

Wood fiber filled high density polyethylene composites (WPCs) were prepared using twin screw extruder and maleated polyethylene as a coupling agent. Bamboo fibers were initially treated with alkali (NaOH), boric acid - borax (Ba-Bx) and borax (Bx). The treated and untreated fibers were used in combination with ammonium polyphosphate (APP) to investigate their synergistic effects on thermal stability, flame retardancy and mechanical properties. Alkali pretreatment (5 % NaOH) of fibers showed significant improvement in performance of APP by increasing thermal stability in WPCs. The derivative thermogravimetric (DTG) results indicate significance of Ba-Bx in promoting char induction at lower temperatures (340 ºC) and thereby, improved the thermal stability in WPCs. Flammability decreased with addition of flame retardant additives. As compared to pure WPCs, composites containing APP 10 % / Ba-Bx 5 % exhibited maximum reduction in average heat release rate (HRR) by 69 %, peak heat release rate (PHRR) by 59 %, total heat released rate (THR) by 48 % and also increased time to ignition (TTI) by 62 %. However, no significant difference was found among the combinations i.e., APP with or without compounds towards reducing the flammability of WPCs. The strength properties also reduced significantly when boron compounds were added along with APP. In general, APP alone (15 %) is enough for imparting thermal stability and flame retardancy in WPCs.

With the aim to reduce the flammability of poly(lactic acid) (PLA), herein, Tris‐phosphaphenanthrene based phosphonate (DOT) originated from 10‐hydroxy‐9,10‐dihydro‐9‐oxa‐10‐phosphaphenanthrene‐10‐oxide (DOPO‐OH) and trihydroxymethyl aminomethane (Tris) was incorporated. Interestingly, DOT showed superior flame‐retardant efficiency for PLA, that was, PLA with 1 wt% DOT displayed a LOI value at 29.0%, about 49.0% increment as compared to virgin PLA, and passed a UL‐94V‐0 rating. Apart from the mentioned, cone calorimeter tests clearly demonstrated that DOT was beneficial for reducing the heat release in the whole combustion to some extent, for example, the peak heat release rate and the maximum average values of heat emission with a reduction of 15% and 17%, respectively. It was speculated that the improved flame retardance of PLA containing DOT was related to the melting droplet‐promotion effect and the vapor‐phase activity of DOT. Meanwhile, thermal stabilities of PLA/DOT were well maintained as compared to virgin PLA. Moreover, the existence of DOT promoted the crystallization of PLA owing to the nucleating effect of DOT. [ABSTRACT FROM AUTHOR]

This study focuses on the synergistic effects of hydroxide based nanoparticles namely aluminum trihydrate (ATH) and zirconium hydroxide (ZHO) on the mechanical characteristics, thermal stability, and flammability of polyester/jute composite material. Polyester/jute composites were fabricated by incorporating different concentrations of both ATH and ZHO nanoparticles (2, 3 and 4 wt%). The weight of jute fabric in all composite has been kept as 40%. The results showed a significant enhancement in tensile, flexural and impact properties of polyester/jute composite after the inclusion (3 wt%) of either type of nanoparticles. The improvement in the mechanical properties is attributed to the existence of OH interaction between ATH, ZHO, and jute fabric, which has been verified through FTIR spectroscopy. The compatibility of the nanoparticles also lead to improved interfacial bonding, which has been discussed after the scanning electron microscopy of the fractured surfaces. An increase in the thermal stability of the composites was also observed through thermogravimetric analysis. Cone calorimetry and horizontal burning tests showed significant enhancement in the fire retardancy of the developed composites due to endothermic decomposition of ATH and ZHO nanoparticles into char layer and water molecules during combustion, contributing strong resistance to heat, oxygen and flammable gases. The synergistic effect of both ATH and ZHO particles enhances mechanical, thermal, and fire retardant properties of polyester/jute composites. [ABSTRACT FROM AUTHOR]

Foamed plastics are increasingly employed due to the high demand in functional materials with reduced weight. Bead foams in general offer low weight and excellent thermal insulation properties combined with extremely high freedom in design. Though foams show increased risk of ignition and heightened heat release, literature on burning behavior is rather limited. Therefore, this study investigates density‐dependent burning behavior of commercial bead foams like expanded polypropylene (EPP) and expanded modified polyphenyleneether (E‐mPPE) by cone calorimetry. The results are compared to existing studies on the density‐dependent burning behavior of different foams, mainly expanded polystyrene and foamed polyurethane. The importance of density as a characteristic is highlighted by the linear dependence of total heat emission on density for all investigated polymers, making a prediction of thermal loads possible. The peak heat release rate of flame‐retarded EPP and E‐mPPE was found not to be dependent on density, indicating an increased homogeneity by addition of flame retardant. [ABSTRACT FROM AUTHOR]

The dodecyl sulfate intercalated CaMgAl‐hydrotalcites (layered double hydroxides [LDHs]) were successfully prepared by co‐precipitation method, and characterized by X‐ray diffraction analysis, infrared spectroscopy (Fourier transform infrared spectra [FT‐IR]), thermogravimetry (TG‐DTA), scanning electron microscope, and Brunner−Emmet−Teller (BET). The prepared LDHs were added to the intumescent flame retardant (IFR) polypropylene (PP) nanocomposites, and the limiting oxygen index method (LOI), vertical combustion method (UL‐94), cone calorimetry (CCT), and other test methods were used to study its thermal stability and combustion performance. The results showed that when the flame retardant was composed of 23 wt% IFR and 2 wt% O‐SDS‐LDHs, the LOI value of the material was increased to 31.5%, reaching the V‐0 level, and the flame retardant performance was significantly improved. The results also showed that there was a significant synergistic effect between IFR and O‐SDS‐LDHs, which could improve the thermal stability and graphitization degree of PP nanocomposites. In addition, the peak heat release rate, total heat release, and total smoke production of the PP/IFR/O‐SDS‐LDHs system were 177 kW/m2, 101 MJ/m2, and 15.4 m2, respectively, which were 82.2%, 51.0%, and 23.0% lower than those of pure PP, respectively. These improvements could be attributed to the presence of dense and continuous char layer formed by the synergistic effect. [ABSTRACT FROM AUTHOR]

Abstract Aiming to overcome poly(lactic acid) (PLA) limitations regarding flammability and high costs, a highly refractory clay (RC) was employed to produce PLA/RC composites. The composites with clay contents of 0, 2.5, 10 and 15 wt% were produced by extrusion, conformed by injection molding, and characterized by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), mechanical analysis, scanning electron microscopy (SEM), Fourier Transform Infrared Spectroscopy (FTIR), statistical analysis of variance (ANOVA) and flammability tests. The overall thermal stability of the materials was not affected by the incorporation of clay to the polymer matrix; improvements around 25% for Young’s modulus and slight increase in flexural and impact strength, when compared to neat PLA, were obtained; ANOVA showed the possibility of incorporating higher loads of clay, 10-15 wt%, in order to make the final material more cost effective. PLA/RC composites demonstrated self-extinguish behavior for the flame even at a lower clay content.

Silica (SiO2) nanohybrid expandable graphite (nEG) particles fabricated through one‐step method are used as an efficient flame retardant for polypropylene (PP)/polyamide 6 (PA6) blends. The effect of nEG on the flammability, thermal stability, crystallization behaviors, and mechanical properties of PP/PA6 composites is investigated by using limit oxygen index (LOI), UL‐94 test, cone calorimeter test (CCT), thermogravimetric analysis, differential scanning calorimetry, Fourier transform infrared, scanning electron microscopy, and mechanical tests. Compared with pure expandable graphite (EG), nEG improves the flame retardancy of composites. The results of LOI show that LOI of PP/PA6/nEG10 and PP/PA6/nEG15 composites are 26.0% and 27.2%, respectively. But the LOI values of PP/PA6/EG10 and PP/PA6/EG15 composites are 25.7% and 26.9%, respectively. The UL‐94 test results show that PP/PA6/nEG10 composites reach V‐1 level when the nEG content is only 10%. However, the PP/PA6 composites with 10% EG does not pass the UL‐94 test. In addition, PP/PA6 composites with 15% nEG can reach V‐0 level. The CCT results further show that nEG has a higher flame‐retardant efficiency than pure EG for PP/PA6 blends. The thermal stability of PP/PA6/nEG composites is better than that of PP/PA6/EG composites. The mechanical property tests indicate that nEG is more conducive to maintain the tensile and impact strengths of PP/PA6 blends than EG due to the enhanced compatibility and interfacial adhesion. [ABSTRACT FROM AUTHOR]

A novel microcapsule flame retardant microencapsulated aluminum hypophosphite (MAHP) was introduced. Fourier transform infrared spectroscopy, scanning electron microscopy, and x‐ray photoelectron spectroscopy were used to characterize the shell material on the surface of MAHP. The water contact angle (WCA) experiments show that the WCA of MAHP (71.4°) is significantly larger than that of aluminum hypophosphite (34.4°). And the interfacial free energy between MAHP and epoxy resin (EP) is only 7.89 mJ/m2, which results in good compatibility with EP. The results from differential scanning calorimeter test indicate that the addition of MAHP can improve the heat resistance of EP matrix. Thermogravimetric (TG) tests show that EP/MAHP has the largest amount of residue (32.03 wt%). The combustion behaviors of flame‐retardant EP (FR‐EP) composites were evaluated by limiting oxygen index, UL‐94, and cone calorimetry. The results show that the microencapsulation to AHP in this study can significantly improve the flame retardancy of EP. Thermogravimetric infrared analysis was used to investigate the gas‐phase products. Surface morphology and structure of char residues of EP and FR‐EP was also studied. The carbon layer became quite dense and continuous when MAHP was added. On the premise of improving the flame retardancy, the mechanical properties of the material are retained. The tensile strength and bending strength of EP/MAHP‐3 were 23.98 and 50.75 MPa, respectively. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Textiles & Engineers / Tekstil ve Mühendis is the property of Union of Chambers of Turkish Engineers & Architects, Chamber of Textile Engineers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Over past few decades, the electronic boards density and performance are enhanced by entrenching the components in the interior surfaces of the printed circuit boards (PCBs).The worthiness of this novel innovation has to be probed to warranty the functioning of electronic boards acquiesced to callous environments. In this study, a novel advancement concentrating on the development of bio‐based materials for the PCB applications has been documented. The bio‐based composite from rice husk‐epoxy resin could impendingly substitute the conventional synthetic fiber reinforced epoxy composites in PCB applications. The essential properties of biocomposites were assessed such as tensile and bending properties, dielectric property, thermal properties, moisture absorption, microdrilling, biodegradability, and flammability. Results obtained found that, these biocomposites were promising for PCB application. [ABSTRACT FROM AUTHOR]

Linseed cake (LC), a by‐product of oil extraction from linseed, due to high content of natural oil can be applied as a filler and modifying agent for polymeric composites. However, the presence of the flammable oil may change thermal properties of the resulting materials. The aim of this study is evaluation of the influence of oil content on flammability and thermal degradation of polylactide composites. The samples filled with 10 wt% of LC containing from 0.9% to 39.8% of oil were subjected to cone calorimetry, horizontal burning test and thermogravimetric analysis. Activation energy values of the thermal decomposition of the composites were calculated using Ozawa and Kissinger methods. The different LC grades and the crude oil were tested as well. Even though all the composite grades presented higher flammability and lower thermal stability than the neat resin, their burning behavior and the process of thermal decomposition did not depend on the oil content. Therefore, the oil‐rich grades of LC can be applied as an effective filler for polylactide without an increase in fire risk. [ABSTRACT FROM AUTHOR]

This study focused on the burning phenomena, thermal stability, and physicomechanical properties of polyurethane foam based on recycled poly(ethylene terephthalate) (RPUF) with and without halogen‐free flame retardants (FRs). Flammability behavior and associated mechanisms were studied by cone calorimetry, LOI, UL 94, FTIR, TGA, FE‐SEM, and XPS. The results of cone calorimeter testing indicate improved FR performance with notable reductions in peak heat release rate (~39.1%), peak CO production (~61.7%), and peak CO2 production (~43.0%). LOI values significantly increase, up to 29.5–47.1%, in the presence of FRs, and V‐0 ratings are attained even at a rather low loading of FR (6.07 wt%). Meanwhile, the RPUF completely burns to the holder clamp with a low LOI value (17%), and it do not pass the UL94 HB standard. The addition of FRs notably improves the residual char of RPUF, indicating that FRs contributed to the formation of a barrier layer to protect RPUF during degradation. The comparison between experimentally determined TGA results and calculated values provides support for the effect of FRs on the thermal degradation behavior of RPUF. Sorption isotherm experiments of RPUF/FR systems show low moisture absorptivity and a weak hysteresis effect due to strong intermolecular bonds between RPUF and added FRs. The compression test, density, and morphology of foam samples are also discussed. [ABSTRACT FROM AUTHOR]

Reduction of flammability and improvement of thermal stability of polymers during heating can be achieved by the introduction of fillers. Epoxy composites filled with different loadings of multi-walled carbon nanotubes (MWCNTs) and expanded graphite (EG) were prepared. The thermal oxidation stability of the prepared samples was investigated under heating in an oxidizing atmosphere using thermal analysis. The hardness was measured using the Shore D hardness test. The flammability of the prepared composites was evaluated by the ignition temperature and time-to-ignition. It was found that there was a rise in temperature corresponding to a 5% weight loss during heating for both epoxy/MWCNT and epoxy/EG composites compared to neat epoxy resin. The Shore D hardness of epoxy/MWCNT composites increased with content growth up to 0.1 wt.% and decreased with further concentration rise. The addition of MWCNTs and EG leads to an increase in the ignition temperature. It has been shown that MWCNTs improve the thermal behavior of epoxy resin in a low temperature region (below ~300 °C) whereas EG shows almost the same thermal behavior above 300 °C. The improvement of thermal properties can be achieved using MWCNTs and EG as fillers. [ABSTRACT FROM AUTHOR]

Nowadays, increasing attention is devoted to the search for polymeric composite materials that are characterized by reduced flammability. In this work, the layer-by-layer (LbL) technique was applied to form multilayered protective coatings for polyamide 6/montmorillonite (PA6/MMT) hybrid nanocomposites. This time, the double layers LbL deposition was used in order to improve the thermal properties or flammability of PA6 materials. Our goal was to check how five, 10, and 15 triple-layer deposition onto the surface of PA6 and PA6/MMT composites influenced these relevant properties. For this reason, disodium H-phosphonate, sodium montmorillonite, and iodo-bis(triphenylphosphino)copper were used for polyelectrolyte solution preparation. It was found that the LbL method could be successfully used to improve the flammability characteristics of polyamide 6-based composites. Nevertheless, the deposition of the copper complex should be combined with other flame retardants—preferentially containing phosphorus—which enable synergistic effects to occur. Moreover, microscopic observations confirmed that the surfaces on which the formation of interwoven fibrous crystal structures was observed had a tendency to protect the entire material against the destructive effects of heat, contributing, among other things, to reduce the maximum point of heat release rate (PHRR). [ABSTRACT FROM AUTHOR]

Multiwall carbon nanotubes (CNT) or montmorillonite clay (MMT‐30B) were added to a poly(hexamethylene isophthalamide‐co‐terephthalamine) (an amorphous polyamide ‐ aPA) and styrene‐ethylene/butylene‐styrene graphitized with maleic anhydride (SEBS) blend, in different concentrations, in order to investigate the morphology, thermal properties and flammability behavior. Different nanoparticle localizations in the phase blend were observed through transmission electronic microscopy. CNT nanoparticles are localized in SEBS phase, and MMT‐30B nanoparticles in aPA phase. No significant changes were observed on transition temperatures and thermal stability with both nanoparticle additions. However, a slight increase on storage modulus for clay nanocomposites and a slight reduction for carbon nanotube nanocomposites were observed, due to their different phase localizations. Regarding flammability, CNT nanocomposites showed better performance as a flame retardant when compared to samples with MMT‐30B. Although the MMT‐30B nanocomposites could not be classified according to the UL‐94 criteria, no dripped flaming particles were observed, due to the a char barrier formation on the polymer surface. The CNT nanocomposites were classified according to the UL‐94 criteria as V‐2. The CNT's selective localization on the SEBS phase decreases its heat‐release rate, but no interconnected network structure was formed in the matrix to suppress the dripping flaming particles. [ABSTRACT FROM AUTHOR]

Copyright of Polimery is the property of Industrial Chemistry Research Institute and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Herein, Ti3C2Tx (MXene) was synthesized and mixed with polyvinyl alcohol (PVA) to fabricate PVA/MXene nanocomposites. The results confirmed that delaminated MXene was successfully synthesized. The nanocomposites were obtained via casting/evaporation method. The thermal stability was evaluated by thermogravimetric analysis (TGA). For the PVA composites with content of 2 wt% MXene (PVA‐MXene2), the thermal decomposition was retarded by approximately 20°C when the temperature was lower than 350°C compared with that of pure PVA. Moreover, the evolved gas products of the PVA/MXene composite were lower than those of pure PVA. For the first time, the flame retardancy of PVA/MXene nanocomposite was investigated using a microscale combustion calorimeter. The peak heat release rate (PHRR) and total heat release of the PVA composite were reduced by 25.7% and 25.5%, respectively, with 1 wt% of MXene. The temperatures at PHRR of PVA/MXene composites were improved with the addition of MXene. Moreover, the addition of MXene resulted in PVA composites with a higher tensile strength and elongation at break than those of a pure PVA film. The improvements in the flame retardancy, thermal and mechanical properties of PVA/MXene composites should enable a wide range of potential applications of MXenes in polymer matrices. [ABSTRACT FROM AUTHOR]

A novel bio-based flame-retardant thermosetting vinyl ester resin monomer was synthesized from castor oil. The chemical structures of the monomer was characterized by FTIR and 1H-NMR. In order to improve its rigidity and expand its application in the field of bio-based materials, it was mixed with certain proportions of another reactive bio-based VER monomer, which had rigid and strong polar groups, and then a series of copolymers were prepared with thermal curing method. Then their tensile property, hardness, morphology of fractured surface, flame retardant property, DMA and thermostability were all investigated. The results indicated that the copolymers had relatively high tensile strength of 11.2 MPa, and the limiting oxygen index is above 23% in all prepared copolymers. DMA demonstrates that the glass transition temperature of the cured resins is up to 56.1°C. Thermogravimetric analysis shows that the copolymers have excellent thermal stability.

Summary: This study investigates the incorporation of castor oil–based rigid polyurethane foam with mineral fillers feldspar or kaolinite clay in order to enhance the mechanical, thermal, and flame retardant properties. Influence of mineral fillers on the mechanical strength was characterized by compressive strength and flexural strength measurement. Thermogravimetric analysis (TGA) was performed to diagnose the changes in thermal properties, while cone calorimeter test was performed to ascertain the flame retardancy of the mineral filler–incorporated rigid polyurethane foam composites. Results showed that the foams incorporated with mineral filler demonstrated up to 182% increase in compressive strength and 351% increase in flexural strength. Thermal stability of these composite foams was also found to be enhanced on the incorporation of kaolinite clay filler with an increase in 5% weight loss temperature (T5%) from 192°C to 260°C. Furthermore, peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), and total smoke release (TSR) were also found to decreased on the incorporation of mineral filler in the rigid polyurethane foam. So mineral fillers are ascertained as a potential filler to enhance the mechanical, thermal, and flame retardant behaviors of bio‐based rigid polyurethane foam composites. [ABSTRACT FROM AUTHOR]

This paper is focused on the assessment of fire hazards of lithium-ion electrolytes. The electrolytes are flammable mixtures that contain LiPF6 salt, which release toxic gas during the burning process. The combustion behavior of lithium-ion electrolytes is studied using a series of pool-fire experiments through typical fire parameters, including flame radiation, burning rate, and fuel temperature. The liquid--vapor phase equilibrium process of electrolyte solvents is also analyzed based on phase-equilibrium theory. The results show that the burning process of the electrolyte is controlled by different components at different burning stages. The burning process of electrolyte pool fires can be divided into three distinct stages: (I) a low-boiling-point-component-controlled stage, (II) an intermediate transition stage, and (III) a high-boiling-point-component-controlled stage. The LiPF6 salt can obviously influence the flame luminosity of the pool fire in stage I, but has almost no influence on the radiant heat flux of the flame. The LiPF6 salt mainly influences stage II and stage III, in which a large amount of smoke gas is released. Stage II may be halted to extinguish owing to the high concentration of salt, and the EC/DMC and EC/DEC/DMC electrolyte mixtures become extinguished and cannot continue to burn. The vapor--liquid phase diagram for two binary electrolytes is made based on phase-equilibrium theory, and the predicted boiling point agrees well with the measured boiling temperature. [ABSTRACT FROM AUTHOR]

The structure, thermal stability, and mechanical properties of electrospun nanofiber mats obtained from poly(ethylene terephthalate) (PET) solutions in trifluoroacetic acid/dichloromethane were evaluated. The electrospun PET nanofibers were characterized by means of attenuated total reflection Fourier transform infrared spectroscopy, scanning electron microscopy, differential scanning calorimetry, thermogravimetric analysis, limiting oxygen index, and tensile testing. PET-3-hydroxyphenylphosphinyl-propanoic acid (HPP) copolymer was used as the flame-retardant (FR) agent to improve the thermal stability and flammability of the nanofiber mats. HPP is a commercial FR for polyesters which was studied from the viewpoint of chemical reactivity and reaction mechanism. To enhance the tensile strength of the nanofiber mats, the nanofibers were collected on high-speed rotating drum. The results showed that the nanofibers were oriented, and their strength was enhanced by increasing the velocity of the collector. The average diameter of electrospun nanofibers was in the range of 110–240 nm, decreasing with the increasing drum speed. Also the mean pore size of the mats decreased significantly with increasing orientation of the nanofibers. The results showed that HPP improved the flame retardancy of PET. [ABSTRACT FROM AUTHOR]

The objective of this study is to determine the effects of dolomite content on flammability, thermal and mechanical properties of polybutylene terephthalate (PBT)/dolomite composites. PBT and dolomite were blended together at different dolomite contents (5 wt%, 10 wt% and 15 wt%) via twin screw extruder prior to injection moulding. Limiting oxygen index (LOI) test was used to determine the flammability of the PBT composites. Degree of crystallisation (Xc), glass transition (Tg), melting (Tm) and crystallisation (Tc) temperatures were obtained using differential scanning calorimetry (DSC). Three types of mechanical tests were carried out, i.e., flexural, tensile and Izod impact. Morphological study was characterised using scanning electron microscope (SEM). LOI analysis showed that the incorporation of dolomite reduced the flammability of PBT composites. DSC results showed that dolomite has marginal effect on Tg and Tm of the PBT composites. On the other hand, Tc and Xc increased with increasing dolomite content which indicates that it can be used as a nucleating agent. The presence of dolomite increased the flexural properties, tensile strength and Young's modulus of PBT composites. However, the elongation at break and impact strength were significantly decreased due to poor adhesion between dolomite and PBT. PBT/D-15 composite was found to have the optimum mechanical properties compared with other PBT/dolomite composites. SEM micrograph revealed that dolomite is uniformly distributed at lower dolomite content but agglomerated at higher content. [ABSTRACT FROM AUTHOR]

This paper presents research findings on the influence of alkaline deacetylation on the thermal stability and fire reaction properties of non-pathogenic Basidiomycota fungi (mycelium) grown in molasses. The relationship between deacetylation conditions, such as incubation time and NaOH concentration, and the thermal and fire reaction properties of mycelium was investigated. The degree of deacetylation was also examined for its influence on the high-temperature thermal stability of mycelium, such as char formation. The findings indicated that the high-temperature thermal stability increased as the degree of deacetylation increased due to the conversion of chitin into chitosan as well as the presence of char-promoting hydroxyl‑terminated polysaccharide moieties. The study further investigated the influence of hollow glass microspheres on the thermal properties and microscale combustion behaviour of unmodified and deacetylated mycelium. This study provides an in-depth analysis of the thermal degradation mechanisms that govern the thermal stability and char-forming ability of unmodified and deacetylated mycelium. Additionally, the link between the thermal stability and fire reaction properties of mycelium and its deacetylated derivatives was established. Finally, the effectiveness of unmodified and deacetylated mycelium mats for fireproofing flammable glass fibre-reinforced epoxy laminates exposed to a simulated moderate-intensity fire was evaluated. [Display omitted] [ABSTRACT FROM AUTHOR]

A novel flame-retarded polymer composites using cow horn ash particles (CHAp) were investigated. The cow horn ash particles were varied in the polyester from 5 to 20 wt% with 5 wt% interval. Thermogravimetric analysis (TGA) and cone calorimeter test were used to determine the flame-retarded properties of the developed composites. Weight of 5.28, 5.285, 8.47, 11.64, and 17.67% were left at 0, 5, 10, 15, and 20 wt% CHAp. Twenty percent of the weight remained at around 500 °C as the weight percentage addition of CHAp increased up to 20 wt%. The introduction of CHAp particles to polyester induces protective barriers against thermal decomposition and retards the thermal decomposition of polyester/CHAp composite. This work shows that at 20 wt%, CHAp can serve as flame retard in the sense that the CHAp delays the ignition time by 39.93% of the composite and the end of burning time by 30.59% and reduced the total heat release rate by 34.07%. Waste cow horn can be used as flame retardant to polymer composites. [ABSTRACT FROM AUTHOR]

A flame retardation property of polymer composites is being considered important to minimize the amount of heat release and the smoke production during the combustion. Therefore, this work aims to improve the flame retardation property of epoxy composites using ammonium polyphosphate (APP), one of the intumescent flame retardants (IFRs). However, APP could be migrated to the surface of composite due to the weak compatibility with epoxy resin. To prevent the migration, the surface modification method has taken place using various amines, acting as charring agent. In this study, we select the 4,4′-diaminodiphenylmethane (DDM) as both curing agent and charring agent for the surface modification on the APP, and their epoxy composites were prepared. Interestingly, we observe both the fast curing effect by analyzing the curing behavior of epoxy composite by Friedman method, and significant improvements of the thermal degradation, and flame retardancy of epoxy with adding the amine-modified APP (mAPP). Moreover, the epoxy/mAPP composites showed higher flame retardation properties and formed the compact char structures due to the attached DDM, which acted as an efficient charring agent to promote to form the carbonaceous char structures. Finally, we also found the correlation between the improvements of flame retardation properties, and char structures of epoxy composites by calculating the crosslink density (M c) using the theory of rubber elasticity. • Amine-modified ammonium polyphosphate was prepared via cationic ion exchange reaction with 4,4′-diaminodiphenylmethane. • The attached DDM can contribute to accelerate the curing and improve the flame retardation properties of epoxy composites.. • The relationship of flame retardation properties and char structure was found using theory of rubber elasticity. [ABSTRACT FROM AUTHOR]