Polyethylene-based single polymer laminates: Synergistic effects of nanosilica and metal hydroxides

2018 ◽  
Vol 38 (2) ◽  
pp. 62-73 ◽  
Author(s):  
Andrea Dorigato ◽  
Giulia Fredi ◽  
Luca Fambri ◽  
José-Marie Lopez-Cuesta ◽  
Alessandro Pegoretti
Keyword(s):  
Polymer Composites ◽  
Magnesium Hydroxide ◽  
Synergistic Effects ◽  
Cone Calorimetry ◽  
Polyethylene Matrix ◽  
Limiting Oxygen Index ◽  
Fumed Silica Nanoparticles ◽  
Degradation Temperature ◽  
Peak Heat Release Rate ◽  
Polymer Laminates

This work aims to investigate the fire performance of novel polyethylene-based single polymer composites. Fumed silica nanoparticles and magnesium hydroxide microfiller were added at an optimized concentration to a linear low-density polyethylene matrix, which was then reinforced with ultra-high molecular weight polyethylene fibers. Through the optimization of the production process, it was possible to limit the porosity inside the single polymer composites, thus retaining the pristine mechanical properties of the fibers. The addition of SiO2 and magnesium hydroxide determined an increase in the elastic modulus in both the longitudinal and transversal direction, but it concurrently led to a reduction in ductility, especially in the transversal direction. The fillers were proved to bring interesting improvements of the thermal degradation resistance and of the flame behaviour. Thermogravimetric analysis tests highlighted an increase in the onset degradation temperature and in the temperature associated to the maximum degradation rate. Moreover, both the oxidation onset temperature and limiting oxygen index were considerably improved. Cone calorimetry tests evidenced that filled single polymer composites were characterized by lower peak heat release rate and total heat released with respect to neat single polymer composites.

scholarly journals Synergistic effects of metal hydroxides and fumed nanosilica as fire retardants for polyethylene

2019 ◽  
Vol 2 (1) ◽  
pp. 30-48
Author(s):  
Giulia Fredi ◽  
Andrea Dorigato ◽  
Luca Fambri ◽  
José-Marie Lopez-Cuesta ◽  
Alessandro Pegoretti
Keyword(s):  
Mechanical Properties ◽  
Synergistic Effect ◽  
Silica Nanoparticles ◽  
Synergistic Effects ◽  
Metal Hydroxide ◽  
Flow Index ◽  
Fire Performance ◽  
Cone Calorimetry ◽  
Neat Polymer ◽  
Limiting Oxygen Index

AbstractThis work aims to study the synergistic effect of aluminum/magnesium hydroxide microfillers and organomodified fumed silica nanoparticles as flame retardants (FRs) for linear low-density polyethylene (LLDPE), and to select the best composition to produce a fire-resistant polyethylene-based single-polymer composite. The fillers were added to LLDPE at different concentrations, and the prepared composites were characterized to investigate the individual and combined effects of the fillers on the thermo-oxidation resistance and the fire performance, as well as the microstructural, physical, thermal and mechanical properties. Both filler types were homogeneously distributed in the matrix, with the formation of a network of silica nanoparticles at elevated loadings. Melt flow index (MFI) tests revealed that the fluidity of the material was not considerably impaired upon metal hydroxide introduction, while a heavy reduction of the MFI was detected for silica contents higher than 5 wt%. FRs introduction promoted a noticeable enhancement of the thermo-oxidative stability of the materials, as shown by thermogravimetric analysis (TGA) and onset oxidation temperature (OOT) tests, and superior thermal properties were measured on the samples combining micro- and nanofillers, thus evidencing synergistic effects. Tensile tests showed that the stiffening effect due to a high content of metal hydroxide microparticles was accompanied by a decrease in the strain at break, but nanosilica at low concentration contributed to preserve the ultimate mechanical properties of the neat polymer. The fire performance of the samples with optimized compositions, evaluated through limiting oxygen index (LOI) and cone calorimetry tests, was strongly enhanced with respect to that of the neat LLDPE, and also these tests highlighted the synergistic effect between micro- and nanofillers, as well as an interesting correlation between fire parameters and viscosity.

scholarly journals 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 ◽  
2018 ◽  
Vol 11 (1) ◽  
pp. 48 ◽  
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.

Synergism between Intumescent Flame Retardant and Organo-Montmorillonite in Polypropylene Nanocomposites

2013 ◽  
Vol 785-786 ◽  
pp. 502-507 ◽  
Author(s):  
Ya Jun Chen ◽  
Chao Wang ◽  
Chun Zhuang Yang
Keyword(s):  
Cone Calorimeter ◽  
Melt Blending ◽  
Cone Calorimetry ◽  
Simple Method ◽  
Limiting Oxygen Index ◽  
Average Mass ◽  
Polypropylene Nanocomposites ◽  
Peak Heat Release Rate ◽  
Izod Impact ◽  
Lower Height

A simple method of melt blending was used to prepare PP, PP/IFR and PP/IFR/OMMT composites. The Flammability and mechanical property of the composites were investigated. Limiting oxygen index (LOI) tests and cone calorimetry results indicate that there are synergisms between IFR and OMMT. Incorporation of OMMT led to a further increase in LOI value of intumescent retarded PP samples when the addition amounts of OMMT are less than 2%. Cone calorimeter measurements demonstrate that the peak heat release rate (PHRR), average mass loss rates (AMLR) and fire growth rate index (FIGRA) of PP/IFR/OMMT composites are all less than that of PP/IFR30 when OMMT contents are less than 1.5% (including 1.5%).Char residues after cone calorimeter tests were investigated. Unlike the expansion char residue of PP/IFR, the char residues of PP/IFR/OMMT display a lower height and compact morphology, which are due to the barrier effect of OMMT. The presence of less than 1.5% OMMT can somewhat enhance the tensile strength and Izod impact strength of PP/IFR/OMMT composites. Larger OMMT amounts decrease the above mechanical properties.

scholarly journals Flame Retardancy and Mechanical Properties of Chitosan and DOPO with Different Mass Ratios in Epoxy Resin

2021 ◽  
Author(s):  
Junjie Wang ◽  
Xinyu Wang ◽  
Chenyu Zhou ◽  
Zhiquan Pan ◽  
Hong Zhou
Keyword(s):  
Mechanical Properties ◽  
Heat Release ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Synergistic Effects ◽  
Resin Matrix ◽  
Simultaneous Increase ◽  
Combined System ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index

Abstract This work focused on the effects of chitosan (CS) and 9,10-dihydro-9-oxo-10-phosphaphenanthrene-10-oxide (DOPO) on the flammable propertied of epoxy resin matrix. The EP composites were fabricated by direct mixing method through a general curing method. The influence of CS, DOPO and CS / DOPO on the resin was investigated through cone calorimetry tests (CC), UL-94 vertical burning, limiting oxygen index (LOI), thermal gravimetric analyzer (TGA), differential scanning calorimeter (DSC) and thermogravimetric analyzer-Fourier infrared combined system (TG-FTIR). The char residues of modified EPs after CC tests were investigated by FTIR, EDX and XPS. Under the 10% addition of CS / DOPO in EP, with the mass ratio of CS and DOPO of 1 : 1, 1 : 2, 1 : 3, 2 : 1 and 3 : 1, the flame retardancy properties of EPs all increased, but only if EP/10% CS1/DOPO2 and EP/10% CS2/DOPO1 achieved a V-0 rating and their values of LOI were 33.7% and 32.5%, respectively. Compared with EP, the peak heat release rate, peak smoke produce rate and total heat release of EP/10% CS1/DOPO2 and EP/10% CS2/DOPO1 decreased, especially, total smoke release decreased by 61.9% and 71.0%, the char residuals amount increased by 84.3% and 41.6%, and the average CO2 yield decreased by 55.4% and 55.0%, respectively. It is worth nothing that the mechanical properties increased, especially the flexural strength increased by 36.0% and 38.4%, respectively. The results indicated that DOPO and CS had important synergistic effects for simultaneous increase both the flame retardancy and mechanical properties of EP composites.

Polysiloxane Flame Retardant Containing Phosphorus and Nitrogen for Cotton Fabrics

2021 ◽  
Vol 8 (3) ◽  
pp. 33-39
Author(s):  
Chen Chen ◽  
Shuai Wang ◽  
Zheng Zhang ◽  
Dongdong Wei ◽  
Jian Liu ◽  
...  
Keyword(s):  
Chemical Structure ◽  
Phosphinic Acid ◽  
Cotton Fabrics ◽  
Cone Calorimetry ◽  
Residual Rate ◽  
Limiting Oxygen Index ◽  
H Nmr ◽  
Peak Heat Release Rate ◽  
Char Length ◽  
C Nmr

Poly[tetra(tetramethylcyclosiloxyl-piperazin)-phosphinic acid methyl ether) (PNCTSi) was successfully synthesized, and its chemical structure was investigated by Fourier transform infrared spectra (FTIR) and nuclear magnetic resonance (1H-NMR and 13C-NMR) spectroscopy. The flammability and thermal decomposition behaviors of cotton fabrics treated with PNCTSi were systematically evaluated by limiting oxygen index (LOI), vertical burning test (UL-94), thermogravimetric analysis (TGA), and cone calorimetry. As a result, the LOI value reached 30.1% and the char length decreased to 10.3 cm when cotton fabrics were treated in 300 g/L of PNCTSi solution for 30 min. According to TGA results, the residual rate of treated cotton fabrics at 800 °C increased to 16.4%. The peak heat release rate (PHRR) and CO2/CO ratio significantly decreased.

scholarly journals Effects of Various Types of Expandable Graphite and Blackcurrant Pomace on the Properties of Viscoelastic Polyurethane Foams

Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1801
Author(s):  
Rafał Oliwa ◽  
Joanna Ryszkowska ◽  
Mariusz Oleksy ◽  
Monika Auguścik-Królikowska ◽  
Małgorzata Gzik ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Structure ◽  
Oxygen Index ◽  
Polyurethane Foams ◽  
Expandable Graphite ◽  
Ftir Analysis ◽  
Limiting Oxygen Index ◽  
Peak Heat Release Rate ◽  
Physical And Chemical ◽  
Scanning Electron

We investigated the effect of the type and amount of expandable graphite (EG) and blackcurrant pomace (BCP) on the flammability, thermal stability, mechanical properties, physical, and chemical structure of viscoelastic polyurethane foams (VEF). For this purpose, the polyurethane foams containing EG, BCP, and EG with BCP were obtained. The content of EG varied in the range of 3–15 per hundred polyols (php), while the BCP content was 30 php. Based on the obtained results, it was found that the additional introduction of BCPs into EG-containing composites allows for an additive effect in improving the functional properties of viscoelastic polyurethane foams. As a result, the composite containing 30 php of BCP and 15 php of EG with the largest particle size and expanded volume shows the largest change in the studied parameters (hardness (H) = 2.65 kPa (+16.2%), limiting oxygen index (LOI) = 26% (+44.4%), and peak heat release rate (pHRR) = 15.5 kW/m2 (−87.4%)). In addition, this composite was characterized by the highest char yield (m600 = 17.9% (+44.1%)). In turn, the change in mechanical properties is related to a change in the physical and chemical structure of the foams as indicated by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis.

Mechanical and flame retardant properties of isotactic polypropylene/magnesium oxysulfate whisker composite

2017 ◽  
Vol 31 (4) ◽  
pp. 514-534 ◽  
Author(s):  
Li Dang ◽  
Xueying Nai ◽  
Xin Liu ◽  
Donghai Zhu ◽  
Yaping Dong ◽  
...  
Keyword(s):  
Isotactic Polypropylene ◽  
Interfacial Interaction ◽  
Flexural Behavior ◽  
Cone Calorimetry ◽  
Melt Mixing ◽  
Suppression Effect ◽  
Peak Heat Release Rate ◽  
Magnesium Oxysulfate ◽  
Flame Retardant Properties ◽  
Better Than

Isotactic polypropylene (iPP) composites containing magnesium oxysulfate whisker (MOSw) or lauric acid-modified MOSw (LA-MOSw) were prepared via melt mixing in a torque rheometer. Scanning electron microscopy pictures showed that the interface between MOSw and iPP matrix was defined, whereas a vague interface was seen in the iPP–LA-MOSw composites. Mechanical properties of these two groups of composites were investigated in terms of tensile, notched impact, and flexural behavior aspects for the purposes of studying toughening effect of MOSw and LA-MOSw. Tensile results showed that yield strength of composites further reduced with the presence of LA, indicating the decrease in interfacial interaction bewteen iPP matrix and MOSw. As such, LA-MOSw performed better than MOSw in toughening of iPP matrix. Flexural strength and modulus of iPP–MOSw composites increased sharply with the increase in MOSw content, while less dependence on the LA-MOSw content indicated that MOSw was deemed beneficial to increase the stiffness. In addition, flammability properties were investigated by cone calorimetry experiment. The results showed that the peak heat release rate apparently reduced with addition of MOSw or LA-MOSw. Besides, iPP–LA-MOSw composites showed higher specific extinction area values than iPP–MOSw composites, which meant the weaker smoke suppression effect of LA-MOSw. It was chiefly because of the incomplete combustion caused by the continuous and complete charred (MgO) shield. The presence of LA was another possible reason.

Effect of TBPF Microencapsulated Ammonium Polyphosphate on the Properties of Thermoplastic Polyurethane Elastomer

2020 ◽  
Vol 842 ◽  
pp. 16-21
Author(s):  
Wei Ying Gao
Keyword(s):  
Phenolic Resin ◽  
Thermoplastic Polyurethane ◽  
Ammonium Polyphosphate ◽  
Polyurethane Elastomer ◽  
Flame Resistance ◽  
Cone Calorimetry ◽  
Limiting Oxygen Index ◽  
Elongation At Break ◽  
Hard Shell ◽  
Thermoplastic Polyurethane Elastomer

In our previous work, ammonium polyphosphate (APP) microcapsule with the shell of boron modified phenolic resin (BPF) was prepared, recorded as BPFAPP. However, the compatibility and the flame retardancy of BPFAPP in thermoplastic polyurethane elastomer (TPU) are still not very good due to the brittle and hard shell wall. To improve the brittleness of microcapsules shell and the property reinforcements of APP in TPU, APP was encapsulated with the tung oil and boron modified phenolic resin (TBPF) in this paper, recorded as TBPFAPP. The property reinforcements of TBPFAPP in TPU were studied. The thermogravimetry, limiting oxygen index and cone calorimetry analysis showed that TPU/TBPFAPP composite had higher char yield and better flame resistance. The tensile strength and elongation at break showed that the mechanical properties were also significantly improved due to the introduction of α-Eleostearate.

scholarly journals Synergistic Effects of Black Phosphorus/Boron Nitride Nanosheets on Enhancing the Flame-Retardant Properties of Waterborne Polyurethane and Its Flame-Retardant Mechanism

Polymers ◽  
2020 ◽  
Vol 12 (7) ◽  
pp. 1487 ◽  
Author(s):  
Sihao Yin ◽  
Xinlin Ren ◽  
Peichao Lian ◽  
Yuanzhi Zhu ◽  
Yi Mei
Keyword(s):  
Boron Nitride ◽  
Heat Release ◽  
Flame Retardant ◽  
Hexagonal Boron Nitride ◽  
Synergistic Effects ◽  
Waterborne Polyurethane ◽  
Black Phosphorus ◽  
Limiting Oxygen Index ◽  
Polyurethane Composite ◽  
Black Phosphorene

We applied black phosphorene (BP) and hexagonal boron nitride (BN) nanosheets as flame retardants to waterborne polyurethane to fabricate a novel black phosphorus/boron nitride/waterborne polyurethane composite material. The results demonstrated that the limiting oxygen index of the flame-retarded waterborne polyurethane composite increased from 21.7% for pure waterborne polyurethane to 33.8%. The peak heat release rate and total heat release of the waterborne polyurethane composite were significantly reduced by 50.94% and 23.92%, respectively, at a flame-retardant content of only 0.4 wt%. The superior refractory performances of waterborne polyurethane composite are attributed to the synergistic effect of BP and BN in the gas phase and condensed phase. This study shows that black phosphorus-based nanocomposites have great potential to improve the fire resistance of polymers.

Facile preparation of uniform polydopamine particles and its application as an environmentally friendly flame retardant for biodegradable polylactic acid

2020 ◽  
Vol 38 (6) ◽  
pp. 485-503
Author(s):  
Benjamin Tawiah ◽  
Bin Yu ◽  
Anthony Chun Yin Yuen ◽  
Bin Fei
Keyword(s):  
Flame Retardant ◽  
Polylactic Acid ◽  
Flame Retardants ◽  
Environmentally Friendly ◽  
Environmentally Benign ◽  
Commercial Application ◽  
Limiting Oxygen Index ◽  
Gaseous Products ◽  
Peak Heat Release Rate ◽  
Insight Into

The demand for environmentally benign flame retardants for biodegradable polymers has become particularly necessary due to their inherently “green” nature. This work reports intrinsically non-toxic polydopamine (PDA) particles as an efficient and environmentally friendly flame retardant for polylactic acid (PLA). 5 wt% PDA loading resulted in a 22% reduction in the peak heat release rate, 34.7% increase in the fire performance index, and lower CO2 production compared to neat PLA. A limiting oxygen index (LOI) value of 27.5% and a V-2 rating was achieved in the UL-94 vertical burning test. Highly aggregated amorphous particulate char was formed with the increasing content of PDA, and a significant reduction in evolved pyrolysis gaseous products was achieved for the PLA/PDA composites as compared with control PLA. This work provides important insight into the potential commercial application of PDA alone as an efficiently green, environmentally benign flame retardant for bioplastic PLA.

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