An intumescent flame retardant polypropylene system with simultaneously improved flame retardancy and water resistance

A nimble strategy for enabling bioderived flame retardants with strikingly enhanced interfacial compatibility in poly (lactic acid) composites

The utilization of bioderived flame retardants in biodegradable poly (lactic acid) (PLA) has profound practical implications for extending the widespread application of PLA composites and protecting the environment. Nevertheless, there are still certain challenges that require prompt attention, especially the ineffectiveness of bio-based flame retardants and their deterioration of the mechanical properties of PLA. This work introduced triglycidyl isocyanurate (TGIC), which has multiple epoxy functions, into the self-assembly process of phytic acid (PA) and chitosan (CS). The epoxy-modified bioderived flame retardant PA@CS-TGIC (PCT) was well dispersed in the PLA matrix and had a strong interfacial adhesion, while also TGIC had a synergistic char-forming effect. By compounding epoxy-modified ammonium polyphosphate (MAPP), 3%PCT/MAPP-PLA composites may reach a LOI value of 28.8 % and UL-94 V-0 rating. Simultaneously, the melting droplets had been considerably reduced. Tensile strength of the 3%PCT/MAPP-PLA composites was 67.0 MPa, 10.8 % higher than that of pure PLA. This work paves a new avenue for the development of PLA composites with robust mechanical and flame retardant properties.

Simultaneously Enhancing the Flame Retardancy, Water Resistance, and Mechanical Properties of Flame-Retardant Polypropylene via a Linear Vinyl Polysiloxane-Coated Ammonium Polyphosphate

It is challenging to improve the water resistance, flame retardancy, mechanical performance, and balance of halogen-free flame-retardant polypropylene (PP) composites. For this purpose, a linear vinyl polysiloxane (PD) was synthesized and then self-crosslinked under benzoyl peroxide to prepare surface-coated ammonium polyphosphate (APP@PD). Apparently, this linear vinyl polysiloxane self-crosslinking coating strategy was completely different from the commonly used sol-gel-coated APP with silane monomers. After coating, the water contact angles (WCA) of APP and APP@PD were 26.8° and 111.7°, respectively, showing high hydrophobicity. More importantly, PP/APP@PD/dipentaerythritol (DPER) showed a higher limiting oxygen index (LOI) and better UL-94 V-0 rate in comparison with PP/APP/DPER composites. After water immersion at 70 °C for 168 h, only PP/APP@PD/DPER kept the UL-94 V-0 rate and lowered the deterioration of the LOI, reflecting the better water-resistance property of APP@PD. Consistently, the cone calorimeter test results displayed a 26.2% and 16.7% reduction in peak heat release rate (PHRR) and total smoke production (TSP), respectively. Meanwhile, the time to peak smoke production rate (T_PSPR) increased by 90.2%. The interfacial free energy (IFE) between APP@PD and PP was calculated to evaluate the interfacial interaction between PP and APP@PD. A reduction of 84.2% in the IFE between APP@PD and PP is responsible for the improvement in compatibility and the increase in flame retardancy, water resistance, and mechanical properties of the composites.

Mechanical Properties of Polypropylene-Based Flame Retardant Composites by Surface Modification of Flame Retardants

A flame retardant refers to a substance that can be added to a material having the property of being efficiently combusted to improve the material physically and chemically. It should not affect the physical properties required for the final product. Halogen-based compounds are representative flame retardants with excellent flame retardancy. However, their use is limited due to restrictions on the use of chemicals introduced due to human safety. Magnesium hydroxide, one alternative material of halogen flame retardants, is widely used as an eco-friendly flame retardant. However, the most significant disadvantage is high load. To find a solution to this problem, many studies have been conducted by mixing magnesium hydroxide with other additives to create a synergistic effect. In this study, flame retardancy and mechanical properties of polypropylene-based flame retardant composites as a function of mixing surface-modified magnesium hydroxide with phosphorus-based flame retardants were investigated. All materials including PP, additives, and flame retardants were mixed using an extrusion process. Specimens were prepared by an injection process of the compound made after mixing. As a result of the evaluation of the mechanical properties by the modified flame retardant, the relational expression of the mechanical performance degradation as a function of the amount of addition was obtained, and the tensile (CBATS) and bending strength (CBABS) were performed on the amount of flame retardant added. The relational expression obtained in this study is considered to be a formula for predicting the strength reduction according to the addition amount of the modified flame retardant and can be used in industry. In addition, it was found that the addition amount of the modified flame retardant had a greater effect on the lowering of the bending strength.

Recent Advances in Halogen-Free Flame Retardants for Polyolefin Cable Sheath Materials

With the continuous advancements of urbanization, the demand for power cables is increasing to replace overhead lines for energy transmission and distribution. Due to undesirable scenarios, e.g., the short circuit or poor contact, the cables can cause fire. The cable sheath has a significant effect on fire expansion. Thus, it is of great significance to carry out research on flame-retardant modification for cable sheath material to prevent fire accidents. With the continuous environmental concern, polyolefin (PO) is expected to gradually replace polyvinyl chloride (PVC) for cable sheath material. Moreover, the halogen-free flame retardants (FRs), which are the focus of this paper, will replace the ones with halogen gradually. The halogen-free FRs used in PO cable sheath material can be divided into inorganic flame retardant, organic flame retardant, and intumescent flame retardant (IFR). However, most FRs will cause severe damage to the mechanical properties of the PO cable sheath material, mainly reflected in the elongation at break and tensile strength. Therefore, the cooperative modification of PO materials for flame retardancy and mechanical properties has become a research hotspot. For this review, about 240 works from the literature related to FRs used in PO materials were investigated. It is shown that the simultaneous improvement for flame retardancy and mechanical properties mainly focuses on surface treatment technology, nanotechnology, and the cooperative effect of multiple FRs. The principle is mainly to improve the compatibility of FRs with PO polymers and/or increase the efficiency of FRs.

Fabrication of Polypyrrole-Decorated Tungsten Tailing Particles for Reinforcing Flame Retardancy and Ageing Resistance of Intumescent Fire-Resistant Coatings

Polypyrrole-decorated tungsten tailing particles (PPY-TTF) were prepared via the in situ polymerization of pyrrole in the presence of tungsten tailing particles (TTF), and then carefully characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and thermogravimetric analysis (TG) analyses. The effect of PPY-TTF on the flame retardancy, smoke suppression property and ageing resistance of intumescent fire-resistant coatings was investigated by a fire protection test, smoke density test and cone calorimeter test. The results show that PPY-TTF exerts excellent cooperative effect on enhancing the flame retardancy and smoke suppression properties of the intumescent fire-retardant coatings, which is ascribed to the formation of more cross-linking structures in the condense phase that enhance the compactness and thermal stability of intumescent char. The cooperative effect of PPY-TTF in the coatings depends on its content, and the coating containing 3 wt% PPY-TTF exhibits the best cooperative effect among the samples, showing a 10.7% reduction in mass loss and 35.4% reduction in flame-spread rating compared to that with 3% TTF. The accelerated ageing test shows that the presence of PPY-TTF greatly slows down the blistering and powdering phenomenon of the coatings, thus endowing the coating with the super durability of fire resistance and smoke suppression property. This work provides a new strategy for the resource utilization of tungsten tailing in the field of flame-retardant materials.

Comparative Study of Fire Resistance and Char Formation of Intumescent Fire-Retardant Coatings Reinforced with Three Types of Shell Bio-Fillers

Three types of shell bio-fillers, including eggshell (CES), conch shell (CHS) and clamshell (CMS), were prepared by cleaning, ultrasonication and pulverizing processes of biowastes, and then applied to intumescent fire-retardant coatings. The effects of shell bio-fillers with different polymorphs on the fire resistance and char-forming of intumescent fire-retardant coatings were investigated by cone calorimeter test, fire protection tests, smoke density test, thermogravimetric analysis (TG), and the fire resistance and char-forming mechanism of bio-fillers in intumescent fire-retardant coatings were proposed. The results show that three kinds of bio-fillers exert an excellent synergistic effect on enhancing the fire resistance and char-forming properties of the intumescent fire-retardant coatings, while clamshell has the best synergistic efficiency among the bio-fillers. Especially, IFRC-CMS coating containing 3 wt% clamshell shows the best fire protection performance and lowest smoke production and heat release, which offers an equilibrium backside temperature of 134.6 °C at 900 s, a flame-spread rating of 14.4, and a smoke density rating value of 22.8%. The synergistic efficiency of bio-fillers in the intumescent coatings depends on the polymorphs of CaCO₃ in bio-fillers, and aragonite CaCO₃ shows a higher synergistic efficiency compared to calcite CaCO₃ and the mixture of aragonite and calcite CaCO₃. The CMS composed of aragonite shows the best synergistic effect, CHS composed of aragonite and calcite comes second, and CES composed of calcite has the weakest synergistic effect.

Comparative Study of Fire Resistance and Anti-Ageing Properties of Intumescent Fire-Retardant Coatings Reinforced with Conch Shell Bio-Filler

Conch shell bio-filler (CSBF) was prepared by washing, ultrasonicating, and pulverizing of conch shells and then was applied in waterborne intumescent fire-retardant coatings. The influence of CSBF on fire resistance and anti-ageing properties of intumescent fire-retardant coatings were studied by using different analytical methods. The fire protection and smoke density tests showed that when the mass fraction of CSBF was 3%, the resulting FRC3 coating had the optimum synergistic flame-retardant and smoke-suppression effects concomitant with a flame-spread rating of 10.7, equilibrium backside temperature of 152.4 °C at 900 s, and smoke-density rating value of 10.4%, which were attributed to the establishment of a more dense and stable intumescent char layer against heat and mass transfer. Thermogravimetric analysis indicated that the presence of CSBF increased the thermal stability and char-forming performance of the coatings, and the char residue of FRC3 rose to 34.6% at 800 °C from 28.6% of FRC0 without CSBF. The accelerated ageing test suggested that the incorporation of CSBF reduced the migration and decomposition of the flame retardants and the yellowing, blistering, and powdering phenomenon, thus improving the structural stability of the coating, resulting in better durability of flame retardancy and smoke-suppression performance.

Effects of Graphene Nanoplatelets on Mechanical and Fire Performance of Flax Polypropylene Composites with Intumescent Flame Retardant

The integration of intumescent flame-retardant (IFR) additives in natural fiber-based polymer composites enhances the fire-retardant properties, but it generally has a detrimental effect on the mechanical properties, such as tensile and flexural strengths. In this work, the feasibility of graphene as a reinforcement additive and as an effective synergist for IFR-based flax-polypropylene (PP) composites was investigated. Noticeable improvements in tensile and flexural properties were achieved with the addition of graphene nanoplatelets (GNP) in the composites. Furthermore, better char-forming ability of GNP in combination with IFR was observed, suppressing HRR curves and thus, lowering the total heat release (THR). Thermogravimetric analysis (TGA) detected a reduction in the decomposition rate due to strong interfacial bonding between GNP and PP, whereas the maximum decomposition rate was observed to occur at a higher temperature. The saturation point for the IFR additive along with GNP has also been highlighted in this study. A safe and effective method of graphene encapsulation within PP using the fume-hood set-up was achieved. Finally, the effect of flame retardant on the flax–PP composite has been simulated using Fire Dynamics Simulator.

Flame Retardant Polypropylenes: A Review

Polypropylene (PP) is a commodity plastic known for high rigidity and crystallinity, which is suitable for a wide range of applications. However, high flammability of PP has always been noticed by users as a constraint; therefore, a variety of additives has been examined to make PP flame-retardant. In this work, research papers on the flame retardancy of PP have been comprehensively reviewed, classified in terms of flame retardancy, and evaluated based on the universal dimensionless criterion of Flame Retardancy Index (FRI). The classification of additives of well-known families, i.e., phosphorus-based, nitrogen-based, mineral, carbon-based, bio-based, and hybrid flame retardants composed of two or more additives, was reflected in FRI mirror calculated from cone calorimetry data, whatever heat flux and sample thickness in a given series of samples. PP composites were categorized in terms of flame retardancy performance as Poor, Good, or Excellent cases. It also attempted to correlate other criteria like UL-94 and limiting oxygen index (LOI) with FRI values, giving a broad view of flame retardancy performance of PP composites. The collected data and the conclusions presented in this survey should help researchers working in the field to select the best additives among possibilities for making the PP sufficiently flame-retardant for advanced applications.

Combustion Performance and Thermal Stability of Basalt Fiber-Reinforced Polypropylene Composites

In this study, the thermal stability and combustion performance of basalt fiber reinforced polypropylene (BFRPP) composite and pure polypropylene (PP) were compared. The results show that the basalt fiber has no positive effect on increasing the initial decomposition temperature of PP, but it could reduce the maximum thermal decomposition rate and increase the temperature of the maximum thermal decomposition rate. Adding basalt fiber to PP could slightly reduce the limiting oxygen index. At the same oxygen concentration, the BFRPP burned significantly more slowly than the PP. In addition, during the combustion, it was observed that the BFRPP showed a better anti-melt dripping effect than the PP. The results from the cone calorimeter test show that, under the same external heat flux, the time-to-ignition (TTI) of BFRPP was less than that of PP. This indicated that BFRPP was easier to ignite than PP. It was also found that the reciprocal of the square root of the TTI of both has a linear relationship with external heat flux. BFRPP has a lower peak heat release rate and total heat release than PP. Moreover, BFRPP produced less smoke than PP when burned.

A novel organic-inorganic hybrid K-HBPE@APP performing excellent flame retardancy and smoke suppression for polypropylene

To overcome the flammability and severe dripping of polypropylene (PP), a novel organic-inorganic hybrid K-HBPE@APP (microencapsulated APP by a hyperbranched polyester (HBPE) via silane coupling agent (KH-550)) was obtained and used as a high-efficient flame retardant and smoke suppressant. Herein, HBPE acted as the charring agent for APP. 20 wt% of K-HBPE@APP imparted PP excellent flame retardancy, V-0 rating (UL-94 test) and 82.6% decrease in the peak of heat release rate (PHRR). However, PP with 25 wt% of mechanically mixed APP and HBPE achieved V-1 rating (UL-94 test) and 77.3% decrease in PHRR. That is because the direct contact and sufficient interaction between APP and HBPE gives full play to their synergy. Besides, K-HBPE@APP accelerated the formation of cross-linked POC/SiOSi/SiOC/SiOP/POΦ structures, leading to a strong and compact char layer with a result of dramatic reduction in heat release rate and smoke production. Furthermore, K-HBPE@APP was highly water-resistant and has good compatibility with PP matrix. In particular, the flame-retarded PP had similar tensile strength to pure PP and enhanced impact strength.

Synthesis of a Novel Phosphorous-Nitrogen Based Charring Agent and Its Application in Flame-retardant HDPE/IFR Composites

In this work, a novel phosphorous-nitrogen based charring agent named poly(1,3-diaminopropane-1,3,5-triazine-o-bicyclic pentaerythritol phosphate) (PDTBP) was synthesized and used to improve the flame retardancy of high-density polyethylene (HDPE) together with ammonium polyphosphate (APP). The results of Fourier transform infrared spectroscopy (FTIR) and ¹³C solid-state nuclear magnetic resonance (NMR) showed that PDTBP was successfully synthesized. Compared with the traditional intumescent flame retardant (IFR) system contained APP and pentaerythritol (PER), the novel IFR system (APP/PDTBP, weight ratio of 2:1) could significantly promote the flame retardancy, water resistance, and thermal stability of HDPE. The HDPE/APP/PDTBP composites (PE3) could achieve a UL-94 V-0 rating with LOI value of 30.8%, and had a lower migration percentage (2.2%). However, the HDPE/APP/PER composites (PE5) had the highest migration percentage (4.7%), lower LOI value of 23.9%, and could only achieve a UL-94 V-1 rating. Besides, the peak of heat release rate (PHRR), total heat release (THR), and fire hazard value of PE3 were markedly decreased compared to PE5. PE3 had higher tensile strength and flexural strength of 16.27 ± 0.42 MPa and 32.03 ± 0.59 MPa, respectively. Furthermore, the possible flame-retardant mechanism of the APP/PDTBP IFR system indicated that compact and continuous intumescent char layer would be formed during burning, thus inhibiting the degradation of substrate material and improving the thermal stability of HDPE.

Synthesis of a DOPO-triazine additive and its flame-retardant effect in rigid polyurethane foam

A DOPO (9,10-dihydro-9-oxa-10-phosphaphen-anthrene-10-oxide)-based halogen-free flame retardant (ODOPM-CYC) was synthesized and incorporated in rigid polyurethane foam (RPUF). The structure of ODOPM-CYC was characterized by Fourier transform infrared spectra (FTIR), 1H NMR and 31P NMR. The effects of ODOPM-CYC on the flame resistance, mechanical performances, thermal properties and cell structure of RPUF were also investigated. The results showed that the incorporation of ODOPM-CYC strikingly enhanced flame retardant properties of RPUF. The flame retarded RPUF acquired a limiting oxygen index (LOI) value of 26% and achieved UL-94 V-0 rating with the phosphorus content of 3 wt%. The smoke production rate (SPR) also showed an obvious decrease and total smoke release (TSR) was 39.8% lower than that of neat RPUF. Besides, the results demonstrated that the incorporation of ODOPM-CYC provided RPUF better thermal stability but did not show any obvious influence on its thermal conductivity.

Enhancement of an organic-metallic hybrid charring agent on flame retardancy of ethylene-vinyl acetate copolymer

An organic triazine charring agent hybrid with zinc oxide (OTCA@ZnO) was prepared and well characterized through Fourier transform infrared spectrometry (FTIR), solid-state nuclear magnetic resonance (SSNMR), transmission electron microscopy (TEM) and thermogravimetric analysis (TGA). The flame retardancy and thermal behaviour of intumescent flame retardant ethylene-vinyl acetate (EVA) composites combining OTCA@ZnO and ammonium polyphosphate (APP) were investigated using limited oxygen index (LOI), UL-94 vertical burning, cone calorimetry and TGA. The structure and morphology of chars were investigated by scanning electron microscopy (SEM), FTIR, laser Raman spectroscopy analysis (LRS) and X-ray photoelectron spectroscopy (XPS). Results revealed that OTCA@ZnO exhibited excellent thermal stability and dispersity after hybridization. The flame retardancy and smoke suppression properties of EVA were significantly improved by introducing APP/OTCA@ZnO. TGA results indicated that APP/OTCA@ZnO presented an excellent synergistic effect and promoted the char formation of EVA composites. Residue analysis results showed more char with high quality connected by richer P-O-C, P-N and P-O-Si structures was formed in APP/OTCA@ZnO system than APP/HOTCA/ZnO system, which consequently suppressed more efficiently the combustion and smoke production due to the in situ catalytic carbonization effect of hybrid.

Improved Flame-Retardant and Ceramifiable Properties of EVA Composites by Combination of Ammonium Polyphosphate and Aluminum Hydroxide

Ceramifiable flame-retardant ethylene-vinyl acetate (EVA) copolymer composites for wire and cable sheathing materials were prepared through melt compounding with ammonium polyphosphate (APP), aluminum hydroxide (ATH) and fluorophlogopite mica as the addition agents. The effects of ammonium polyphosphate, alumina trihydrate, and APP/ATH hybrid on the flame retardant, as well as on the thermal and ceramifiable properties of EVA composites, were investigated. The results demonstrated that the composites with the ratio of APP:ATH = 1:1 displayed the best flame retardancy and the greatest char residues among the various EVA composites. The tensile strength of the composites was 6.8 MPa, and the residue strength sintered at 1000 °C reached 5.2 MPa. The effect of sintering temperature on the ceramifiable properties, microstructures, and crystalline phases of the sintered specimen was subsequently investigated through X-ray diffraction, Fourier transform infrared, and scanning electron microscopy. The XRD and FTIR results demonstrated that the crystal structure of mica was disintegrated, while magnesium orthophosphate (Mg₃(PO₄)₂) was simultaneously produced at an elevated temperature, indicating that the ceramization of EVA composites had occurred. The SEM results demonstrated that a more continuous and compact microstructure was produced with the rise in the sintering temperature. This contributed to the flexural strength improvement of the ceramics.

Preparation and characterisation of flame retardant encapsulated with functionalised silica-based shell

Intumescent fire retardant (IFR) coatings are nowadays considered as the most effective flame retardant (FR) treatment. Nevertheless, the principal compound in an IFR system, ammonium polyphosphate (APP), is highly sensitive to moisture and IFR coating effectiveness decreases quickly. The main objective of this study is to encapsulate APP in a hybrid silica-based membrane by sol-gel process using alkoxysilane tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) precursor. The morphology and structure of APP and microencapsulated ammonium polyphosphate (MAPP) were assessed by scanning electron microscopy and Fourier transforms infrared spectroscopy (FTIR). X-ray photoelectron spectroscopy (XPS) results revealed that APP was well encapsulated inside the polysiloxane shells. The thermal degradation of APP and MAPP was evaluated by thermogravimetric analysis. At 800 °C, the MAPP had higher char residue (70.49 wt%) than APP (3.06 wt%). The hydrophobicity of MAPP increased significantly with the water contact angles up to 98°, in comparison to 20° for APP.

Novel Core-Shell Hybrid Nanosphere towards the Mechanical Enhancement and Fire Retardance of Polycarbonate

It is a huge challenge to achieve highly efficient fire retardance with no mechanical damage to polymers. In our current research, a novel core-shell titanium dioxide@diphenylphosphinic (TiO₂@DPP) nanosphere was first synthesized through a hydrothermal reacting process, and applied in simultaneously enhancing the fire retardance and mechanical properties of polycarbonate (PC). The well-designed TiO₂@DPP exhibited a significant effect on combustion performance and mechanical reinforcement of PC. At only 0.10 wt % of TiO₂@DPP, PC/TiO₂@DPP passed the UL-94 V-0 rating, and its oxygen index value rose to 29.3%. Moreover, the peak value of the heat release rate was remarkably decreased by 34.1% in the combustion test, accompanied by the formation of more compacted char layer and the release of more incombustible gas. Equally important another aspect is that the PC containing only 0.10 wt % of TiO₂@DPP possessed higher elongation at break and higher tensile strength than pure PC, correspondingly increased by 27.7 and 14.7%. The analysis of the flame-retardant mechanism revealed that the improved fire retardance of PC is primarily ascribed to the barrier action of a cross-linking network containing phosphorus and titanium, the dilution of nonflammable gases such as H₂O, and the quenching effect of free radicals which are from the phosphorous group in the gas phase. All these experimental results demonstrate that the core-shell hybrid TiO₂@DPP may achieve a simultaneous significant improvement in fire retardance and mechanical properties of PC.

The Effects of a Macromolecular Charring Agent with Gas Phase and Condense Phase Synergistic Flame Retardant Capability on the Properties of PP/IFR Composites

In order to improve the efficiency of intumescent flame retardants (IFRs), a novel macromolecular charring agent named poly(ethanediamine-1,3,5-triazine-p-4-amino-2,2,6,6-tetramethylpiperidine) (PETAT) with gas phase and condense phase synergistic flame-retardant capability was synthesized and subsequently dispersed into polypropylene (PP) in combination with ammonium polyphosphate (APP) via a melt blending method. The chemical structure of PETAT was investigated by Fourier transform infrared spectroscopy (FTIR), and ¹H nuclear magnetic resonance (NMR) spectroscopy. Thermal properties of the PETAT and IFR systems were tested by thermogravimetric-derivative thermogravimetric analysis (TGA-DTG) and thermogravimetry–Fourier transform infrared spectroscopy (TG-FTIR). The mechanical properties, thermal stability, flame-retardant properties, water resistance, and structures of char residue in flame-retardant composites were characterized using tensile and flexural strength property tests, TGA, limiting oxygen index (LOI) values before and after soaking, underwritten laboratory-94 (UL-94) vertical burning test, cone calorimetric test (CCT), scanning electron microscopy with energy dispersive X-ray spectrometry (SEM-EDXS), and FTIR. The results indicated that PETAT was successfully synthesized, and when the ratio of APP to PETAT was 2:1 with 25 wt % loading, the novel IFR system could reduce the deterioration of tensile strength and enhance the flexural strength of composites. Meanwhile, the flame-retardant composite was able to pass the UL-94 V-0 rating with an LOI value of 30.3%, and the peak of heat release rate (PHRR), total heat release (THR), and material fire hazard values were considerably decreased compared with others. In addition, composites also exhibited excellent water resistance properties compared with traditional IFR composites. SEM-EDXS and FTIR analyses of the char residues, as well as TG-FTIR analyses of IFR were used to investigate the flame-retardant mechanism of the APP/PETAT IFR system. The results indicated that the efficient flame retardancy of PP/IFR composites could be attributed to the synergism of the free radical-quenching and char layer-protecting mechanisms in the gas phase and condense phase, respectively.

Microencapsulation of ammonium polyphosphate with melamine-formaldehyde-tris(2-hydroxyethyl)isocyanurate resin and its flame retardancy in polypropylene

The reaction scheme of MFT resin pre-polymer.

An efficient method to improve simultaneously the water resistance, flame retardancy and mechanical properties of POE intumescent flame-retardant systems

The water resistance, flame retardancy and mechanical properties of POE intumescent flame-retardant systems were improved simultaneously.