Thermal characterization and flammability of polypropylene containing sepiolite-APP combinations

AbstractThe effects of sepiolite on fire behavior of ammonium polyphosphate-based intumescent flame retardant (IFR)/polypropylene (PP) were investigated. The disaggregation of sepiolite bundles has been provided by wet-milling as the zeta potential value decreased from −9.6 to −31.3 mV. PP and additives were compounded by a twin-screw extruder and molded by injection. A total additive content of 20 wt% in PP and various proportions of sepiolite (1.0–10.0 wt%) in flame retardant (FR) formulation were studied. The flammability of the samples was measured by limit oxygen index (LOI) test and cone calorimetry. The LOI of neat PP (19%) was increased to 32.2% when sepiolite and IFR were used. The peak heat release rate of neat PP (1566.4 kW/m2) was also significantly reduced (94.7 kW/m2) when sepiolite was added with IFR. Thermal analyses results showed that, at higher temperature (700°C), IFR and sepiolite increased the char residue (9 wt%) compared to neat PP (0 wt%).

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Effect of Zinc Borate on Flammability of PET Woven Fabrics

Advances in Polymer Technology ◽

10.1155/2019/7150736 ◽

2019 ◽

Vol 2019 ◽

pp. 1-13 ◽

Cited By ~ 1

Author(s):

Mustafa E. Üreyen ◽

Elif Kaynak

Keyword(s):

Flame Retardant ◽

Synergistic Effects ◽

Fire Retardant ◽

Woven Fabrics ◽

Zinc Borate ◽

Limit Oxygen Index ◽

Wet Milling ◽

Cone Calorimetry ◽

Production Values ◽

Submicron Scale

Zinc borate (ZnB) has been used as a flame retardant, a smoke suppressant, and an antitracking agent in several applications. It may show synergistic effects with antimony oxide and metal hydroxides in fire retardant systems. In this work, the effect of ZnB on the flame retardancy of PET (poly(ethylene terephthalate)) woven fabrics was investigated. In order to provide the homogenous application of ZnB to the fabrics, the particle size of ZnB powders was reduced from 9 μm to submicron scale by wet-milling with zirconia balls followed by high shear fluid processing. ZnB dispersion was mixed with low-formaldehyde melamine resin based cross-linking agent and it was applied to PET fabrics by pad dry cure method. ZnB dispersion was then added in different ratios to alkyl phosphonate and organophosphorus compound based commercial flame retardant finishing agents and applied to the fabrics. The effect of zinc borate with phosphorus based flame retardant (FR) finishing agents was examined by cone calorimetry under a heat flux of 35 kW/m2, vertical flame test, and limit oxygen index. Thermogravimetric analysis was performed up to 800°C under N2 flow. Test results show that zinc borate can be combined with the organophosphorus based commercial FR finishing agents. Zinc borate could not improve the flammability properties of PET fabrics significantly but decreased mean CO, total smoke release, and total smoke production values.

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Synthesis of Novel Polymeric Acrylate-Based Flame Retardants Containing Two Phosphorus Groups in Different Chemical Environments and Their Influence on the Flammability of Poly (Lactic Acid)

Polymers ◽

10.3390/polym12040778 ◽

2020 ◽

Vol 12 (4) ◽

pp. 778 ◽

Cited By ~ 1

Author(s):

Jacob Sag ◽

Philipp Kukla ◽

Daniela Goedderz ◽

Hendrik Roch ◽

Stephan Kabasci ◽

...

Keyword(s):

Flame Retardant ◽

Mode Of Action ◽

Flame Retardants ◽

Fire Behavior ◽

Heat Fluxes ◽

Poly Lactic Acid ◽

Cone Calorimetry ◽

Scanning Calorimetry ◽

Fire Scenarios ◽

Physical Phenomena

Novel polymeric acrylate-based flame retardants (FR 1–4) containing two phosphorus groups in different chemical environments were synthesized in three steps and characterized via nuclear magnetic resonance (NMR) spectroscopy, thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and mass spectrometry (MS). Polylactic acid (PLA) formulations with the synthesized compounds were investigated to evaluate the efficiency of these flame retardants and their mode of action by using TGA, UL94, and cone calorimetry. In order to compare the results a flame retardant polyester containing only one phosphorus group (ItaP) was also investigated in PLA regarding its flame inhibiting effect. Since the fire behavior depends not only on the mode of action of the flame retardants but also strongly on physical phenomena like melt dripping, the flame retardants were also incorporated into PLA with higher viscosity. In the UL94 vertical burning test setup, 10% of the novel flame retardants (FR 1–4) is sufficient to reach a V-0 rating in both PLA types, while a loading of 15% of ItaP is not enough to reach the same classification. Despite their different structure, TGA and cone calorimetry results confirmed a gas phase mechanism mainly responsible for the highly efficient flame retardancy for all compounds. Finally, cone calorimetry tests of the flame retardant PLA with two heat fluxes showed different flame inhibiting efficiencies for different fire scenarios.

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Valorization of Industrial Lignin as Biobased Carbon Source in Fire Retardant System for Polyamide 11 Blends

Polymers ◽

10.3390/polym11010180 ◽

2019 ◽

Vol 11 (1) ◽

pp. 180 ◽

Cited By ~ 6

Author(s):

Neeraj Mandlekar ◽

Aurélie Cayla ◽

François Rault ◽

Stéphane Giraud ◽

Fabien Salaün ◽

...

Keyword(s):

Thermal Stability ◽

Condensed Phase ◽

Flame Retardants ◽

Fire Behavior ◽

Fire Retardant ◽

Ternary Blends ◽

Cone Calorimetry ◽

Polyamide 11 ◽

Twin Screw ◽

Flame Retarded

In this study, two different types of industrial lignin (i.e., lignosulphonate lignin (LL) and kraft lignin (DL)) were exploited as charring agents with phosphorus-based flame retardants for polyamide 11 (PA11). The effect of lignins on the thermal stability and fire behavior of PA11 combined with phosphinate additives (namely, aluminum phosphinate (AlP) and zinc phosphinate (ZnP)) has been studied by thermogravimetric analysis (TGA), UL 94 vertical flame spread, and cone calorimetry tests. Various blends of flame retarded PA11 were prepared by melt process using a twin-screw extruder. Thermogravimetric analyses showed that the LL containing ternary blends are able to provide higher thermal stability, as well as a developed char residue. The decomposition of the phosphinates led to the formation of phosphate compounds in the condensed phase, which promotes the formation of a stable char. Flammability tests showed that LL/ZnP ternary blends were able to achieve self-extinction and V-1 classification; the other formulations showed a strong melt dripping and higher burning. In addition to this, cone calorimetry results showed that the most enhanced behavior was found when 10 wt % of LL and AlP were combined, which strongly reduced PHRR (−74%) and THR (−22%), due to the interaction between LL and AlP, which not only promotes char formation but also confers the stability to char in the condensed phase.

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Combustion properties and pyrolysis kinetics of flame-retardant polyurethane elastomers

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705715598361 ◽

2016 ◽

Vol 30 (2) ◽

pp. 255-272 ◽

Cited By ~ 4

Author(s):

Xilei Chen ◽

Lili Huo ◽

Jianbo Liu ◽

Chuanmei Jiao ◽

Shaoxiang Li ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Pyrolysis Kinetics ◽

Cone Calorimetry ◽

Polyurethane Elastomers ◽

Conversion Rates ◽

Combustion Properties ◽

Peak Heat Release Rate ◽

Fwo Method ◽

Kinetics Of

Flame-retardant polyurethane elastomers (PUEs) have been prepared using trichloroethyl phosphate (TCEP) as flame retardant. The combustion performances and thermal decomposition properties of PUEs were studied using cone calorimetry test and thermogravimetric analysis, respectively. Kissinger method and Flynn–Wall–Ozawa (FWO) method were adopted to discuss the pyrolysis kinetics of PUEs. The experimental results showed that TCEP has good flame-retardant effect for PUE. With the increase of TCEP, the peak heat release rate and total heat release values decrease. A good diagram of linear regression can be obtained from both Kissinger and FWO methods. The activation energy values of flam- retardant PUE can be calculated from FWO method at different conversion rates.

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The intercalation of ammonium sulfamate into kaolinite and its effect on the fire performance of polypropylene

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705717738291 ◽

2017 ◽

Vol 31 (10) ◽

pp. 1352-1370 ◽

Cited By ~ 5

Author(s):

Wufei Tang ◽

Hongfei Li ◽

Sheng Zhang ◽

Jun Sun ◽

Xiaoyu Gu

Keyword(s):

Flame Retardant ◽

Oxygen Index ◽

Potassium Acetate ◽

Limit Oxygen Index ◽

Fire Performance ◽

X Ray Diffraction ◽

X Ray ◽

Peak Heat Release Rate ◽

Ammonium Sulfamate ◽

Xrd Patterns

Kaolinite has often been intercalated before being introduced into polymers to improve its dispersibility; however, the conventional intercalation usually reduces the flame retardancy of the composite. This work reports our recent efforts on improving both the flame retardant efficiency and dispersibility of kaolinite in polypropylene (PP) by intercalating with ammonium sulfamate (AS). The intercalation had been performed through three steps: dimethyl sulfoxide was firstly introduced into kaolinite layers under supersonic wave, then it was replaced by potassium acetate-aqueous (KAc), and finally the intercalated KAc was replaced by AS to obtain AS-intercalated kaolinite. The structure of intercalated kaolinite was characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy, and thermogravimetric analysis (TGA). The flammability evaluation by limit oxygen index, vertical burning test (UL-94), cone calorimeters test (CONE), and TGA indicated that the fire resistance, thermal stability, and physical properties of PP can be effectively enhanced by the introduction of AS-intercalated kaolinite. The peak heat release rate (pHRR) value of PP composite containing only 1.5 wt% intercalated kaolinite (1169 kW m−2) had been reduced 13.2% compared with that of the sample containing 1.5 wt% raw kaolinite (1346 kW m−2). The morphology analysis from scanning electron microscope images and XRD patterns demonstrated that the compatibility and dispersibility of kaolinite in PP had been significantly improved by intercalation. The flame retardant mechanism of AS-intercalated kaolinite in PP was proposed.

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Flame-retardant polyamide 11 nanocomposites: further thermal and flammability studies

Journal of Fire Sciences ◽

10.1177/0734904111404658 ◽

2011 ◽

Vol 29 (6) ◽

pp. 479-498 ◽

Cited By ~ 31

Author(s):

S. C. Lao ◽

J. H. Koo ◽

T. J. Moon ◽

M. Londa ◽

C. C. Ibeh ◽

...

Keyword(s):

Flame Retardant ◽

Twin Screw Extrusion ◽

Cone Calorimetry ◽

Polyamide 11 ◽

Polymer Systems ◽

Low Concentrations ◽

Screw Extrusion ◽

Twin Screw ◽

Nylon 11 ◽

Ul 94

Polyamide (nylon) 11 (PA11) were melt-blended by dispersing low concentrations of nanoparticles (NPs), namely nanoclays (NCs) and carbon nanofibers (CNFs) via twin-screw extrusion. To enhance their thermal and flame retardant (FR) properties, an intumescent FR additive was added to the mechanically superior NC and CNF PA11 formulations. For neat and NP-reinforced PA11 as well as for PA11 reinforced by both intumescent FR and select NPs (NC or CNF), decomposition temperatures by TGA, flammability properties by UL 94, and cone calorimetry values were measured. All PA11 polymer systems infused with both NPs and FR additive had higher decomposition temperatures than those infused with solely FR additive. For the PA11/FR/NC polymer blends, Exolit® OP 1312 (FR2) is the preferred FR additive to pass the UL 94 V-0 requirement with 20 wt%. For the PA11/FR/CNF formulations, all Exolit® OP 1311 (FR1), OP 1312 (FR2), and OP 1230 (FR3) FR additives passed the UL 94 V-0 requirement with 20 wt%.

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Synthesis of a Reactive Template-Induced Core–Shell PZS@ZIF-67 Composite Microspheres and Its Application in Epoxy Composites

Polymers ◽

10.3390/polym13162646 ◽

2021 ◽

Vol 13 (16) ◽

pp. 2646

Author(s):

Kunpeng Song ◽

Yinjie Wang ◽

Fang Ruan ◽

Weiwei Yang ◽

Zhuqing Fang ◽

...

Keyword(s):

Heat Release ◽

Flame Retardant ◽

Epoxy Resin ◽

Mechanical Performance ◽

Hydroxyl Group ◽

Limit Oxygen Index ◽

Composite Microspheres ◽

Peak Heat Release Rate ◽

Interfacial Compatibility ◽

Index Value

Developing superior properties of epoxy resin composites with high fire resistance, light smoke, and low toxicity has been the focus of the research in the flame-retardant field. In particular, it is essential to decrease the emissions of toxic gases and smoke particles generated during the thermal decomposition of epoxy resin (EP) to satisfy the industrial requirements for environmental protection and safety. Consequently, the PZS@ZIF-67 composite was designed and synthesized by employing the hydroxyl group-containing polyphosphazene (poly(cyclotriphosphazene-co-4,4′-dihydroxydiphenylsulfone), PZS) as both the interfacial compatibility and an in situ template and the ZIF-67 nanocrystal as a nanoscale coating and flame-retardant cooperative. ZIF-67 nanocrystal with multidimensional nanostructures was uniformly wrapped on the surface of PZS microspheres. Subsequently, the acquired PZS@ZIF-67 composite was incorporated into the epoxy resin to prepare composite samples for the study of their fire safety, toxicity suppression, and mechanical performance. Herein, the EP/5% PZS@ZIF-67 passed the V-0 rating in a UL-94 test with a 31.9% limit oxygen index value. More precisely, it is endowed with a decline of 51.08%, 28.26%, and 37.87% of the peak heat release rate, the total heat release, and the total smoke production, respectively. In addition, the unique structure of PZS@ZIF-67 microsphere presented a slight impact on the mechanical properties of EP composites at low loading. The PZS@ZIF-67 possible flame-retardant mechanism was speculated based on the analysis of the condensed phase and the gas phase of EP composites.

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Research on the Mechanism of a Novel Si/P Flame Retardant

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.441.436 ◽

2012 ◽

Vol 441 ◽

pp. 436-441 ◽

Cited By ~ 1

Author(s):

Ran Wang ◽

Xiao Chun Wang

Keyword(s):

Fourier Transform ◽

Phosphoric Acid ◽

Heat Release ◽

Flame Retardant ◽

Low Temperatures ◽

Tetraethyl Orthosilicate ◽

Total Heat Release ◽

Cone Calorimetry ◽

X Ray ◽

Peak Heat Release Rate

A novel Si/P flame retardant was prepared using tetraethyl orthosilicate (TEOS) and phosphoric acid (H3PO4). Cotton fabric treated with the flame retardant was characterized by cone calorimetry, thermogravimetric analysis (TGA), X-ray fluorescence spectroscopy, and Fourier transform infrared spectroscopy. The peak heat release rate (pHRR) and total heat release (THR) of the fabric treated with TEOS/H3PO4 are lower than those of the fabric treated with TEOS or H3PO4 alone. The HRR and THR of the treated fabric decrease from 145.66 kW/m2 and 1.68 MJ/m2 to 70.76 kW/m2 and 0.67 MJ/m2, respectively. Total smoke production decreases from 0.080 to 0.014 m2/m2. TGA revealed that cellulose dehydration increases at low temperatures because of the addition of phosphoric acid and the production of charcoal. The generated charcoal is dense. The P and Si contents markedly increase, and exist in the charcoal in the form of P-O-C and Si-O bonds, respectively. On the basis of these results, we conclude that the main mechanism of TEOS/H3PO4 is that of a condensed-phase flame retardant. Good flame retardant synergism occurs between TEOS and H3PO4.

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Investigation of the Flammability and Thermal Stability of Halogen-Free Intumescent System in Biopolymer Composites Containing Biobased Carbonization Agent and Mechanism of Their Char Formation

Polymers ◽

10.3390/polym11010048 ◽

2018 ◽

Vol 11 (1) ◽

pp. 48 ◽

Cited By ~ 17

Author(s):

Muhammad Maqsood ◽

Gunnar Seide

Keyword(s):

Flame Retardant ◽

Cone Calorimetry ◽

Limiting Oxygen Index ◽

Melt Compounding ◽

Char Formation ◽

Peak Heat Release Rate ◽

Flame Retardant Properties ◽

Halogen Free ◽

Intumescent System ◽

Thermal Stability Of

Starch, being a polyhydric compound with its natural charring ability, is an ideal candidate to serve as a carbonization agent in an intumescent system. This charring ability of starch, if accompanied by an acidic source, can generate an effective intumescent flame retardant (IFR) system, but the performance of starch-based composites in an IFR system has not been tested in detail. Here, we describe a PLA-based IFR system consisting of ammonium polyphosphate (APP) as acidic source and cornstarch as carbon source. We prepared different formulations by melt compounding followed by molding into sheets by hot pressing. The thermal behavior and surface morphology of the composites was investigated by thermogravimetric analysis and scanning electron microscopy respectively. We also conducted limiting oxygen index (LOI), UL-94, and cone calorimetry tests to characterize the flame-retardant properties. Cone calorimetry revealed a 66% reduction in the peak heat release rate of the IFR composites compared to pure PLA and indicated the development of an intumescent structure by leaving a residual mass of 43% relative to the initial mass of the sample. A mechanism of char formation has also been discussed in detail.

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Mechanical and thermal characterization of grafted PP-NCC nanocomposites

Journal of Thermoplastic Composite Materials ◽

10.1177/0892705719878226 ◽

2019 ◽

pp. 089270571987822

Author(s):

Saud Aldajah ◽

Mohammad Y Al-Haik ◽

Waseem Siddique ◽

Mohammad M Kabir ◽

Yousef Haik

Keyword(s):

Thermal Properties ◽

Interfacial Adhesion ◽

Thermal Characterization ◽

Mechanical And Thermal Properties ◽

Screw Extruder ◽

Scanning Calorimetry ◽

Three Point Bending ◽

Twin Screw ◽

Thermal Stability Of

This study reveals the enhancement of mechanical and thermal properties of maleic anhydride-grafted polypropylene (PP- g-MA) with the addition of nanocrystalline cellulose (NCC). A nanocomposite was manufactured by blending various percentages of PP, MA, and NCC nanoparticles by means of a twin-screw extruder. The influence of varying the percentages of NCC on the mechanical and thermal behavior of the nanocomposite was studied by performing three-point bending, nanoindentation, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and Fourier-transform infrared (FTIR) spectroscopy tests. The novelty of this study stems on the NCC nanoparticles and their ability to enhance the mechanical and thermal properties of PP. Three-point bending and nanoindentation tests revealed improvement in the mechanical properties in terms of strength, modulus, and hardness of the PP- g-MA nanocomposites as the addition of NCC increased. SEM showed homogeneity between the mixtures which proved the presence of interfacial adhesion between the PP- g-MA incorporated with NCC nanoparticles that was confirmed by the FTIR results. DSC and TGA measurements showed that the thermal stability of the nanocomposites was not compromised due to the addition of the coupling agent and reinforced nanoparticles.

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