scholarly journals Particle Size Related Effects of Multi-Component Flame-Retardant Systems in poly(butadiene terephthalate)

Polymers ◽  
2020 ◽  
Vol 12 (6) ◽  
pp. 1315 ◽  
Author(s):  
Florian Tomiak ◽  
Bernhard Schartel ◽  
Michael Wolf ◽  
Dietmar Drummer
Keyword(s):  
Particle Size ◽  
Flame Retardant ◽  
Synergistic Effects ◽  
Partial Substitution ◽  
Limiting Oxygen Index ◽  
Beneficial Effects ◽  
Fourier Transformation Infrared Spectroscopy ◽  
Component Systems ◽  
Cooling Effects ◽  
And Behavior

Aluminum tris-(diethylphosphinate) (AlPi) is known to have an efficient flame-retardant effect when used in poly(butadiene terephthalates) (PBT). Additionally, better flame-retardant effects can be achieved through the partial substitution of AlPi by boehmite in multi-component systems, which have been shown to be an effective synergist due to cooling effects and residue formation. Although the potential of beneficial effects is generally well known, the influence of particle sizes and behavior in synergistic compositions are still unknown. Within this paper, it is shown that the synergistic effects in flammability measured by limiting oxygen index (LOI) can vary depending on the particle size distribution used in PBT. In conducting thermogravimetric analysis (TGA) measurements, it was observed that smaller boehmite particles result in slightly increased char yields, most probably due to increased reactivity of the metal oxides formed, and they react slightly earlier than larger boehmite particles. This leads to an earlier release of water into the system enhancing the hydrolysis of PBT. Supported by Fourier transformation infrared spectroscopy (FTIR), we propose that the later reactions of the larger boehmite particles decrease the portion of highly flammable tetrahydrofuran in the gas phase within early burning stages. Therefore, the LOI index increased by 4 vol.% when lager boehmite particles were used for the synergistic mixture.

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.

Flame Retardant Polyethylene with Intumescent System Containing Macromolecule-Encapsulated Low Molecular Weight Charring Agent

2007 ◽  
Vol 15 (7) ◽  
pp. 591-596 ◽  
Author(s):  
Meifang Liu ◽  
Xing Huang ◽  
Yuan Liu ◽  
Qi Wang
Keyword(s):  
Flame Retardant ◽  
High Performance ◽  
Flame Retardants ◽  
Synergistic Effects ◽  
Thermoplastic Polyurethane ◽  
Esterification Reaction ◽  
Limiting Oxygen Index ◽  
Charring Agent ◽  
Optimum Formula ◽  
Intumescent System

Intumescent flame retardants are important halogen-free products used in polyethylene. However, their thermal stability and water-resistance are major shortcomings. In this work, a composite charring agent, pentaerythritol (PER) encapsulated by thermoplastic polyurethane (TPU) was used in an intumescent system to improve the flame retardancy of high density polyethylene (HDPE). The encapsulation of macromolecular charring agent TPU can effectively suppress the esterification reaction of PER and acid source in the intumescent system during processing. It can also remarkably decrease the water absorption, thus producing flame retardant HDPE with high performance. The synergistic effects of other common flame retardants including melamine phosphate, melamine polyphosphate and ammonium polyphosphate with TPU-encapsulated PER, as well as the ratio of charring agent to acid source were investigated so as to determine the optimum formula for use in HDPE. The flame retardant HDPE can reach limiting oxygen index of 33 and achieve UL-94 V-0 rating at 3.2 mm thickness when the ratio of MP/composite charring agent is 2:1 w/w.

Synergistic effects of red phosphorus masterbatch with expandable graphite on the flammability and thermal stability of polypropylene/thermoplastic polyurethane blends

2019 ◽  
Vol 28 (3) ◽  
pp. 209-219 ◽  
Author(s):  
Na Wang ◽  
Lingtong Li ◽  
Yang Xu ◽  
Kun Zhang ◽  
Xiaolang Chen ◽  
...  
Keyword(s):  
Thermal Stability ◽  
Heat Release ◽  
Flame Retardant ◽  
Synergistic Effects ◽  
Thermoplastic Polyurethane ◽  
Expandable Graphite ◽  
Gravimetric Analysis ◽  
Red Phosphorus ◽  
Limiting Oxygen Index ◽  
Ul 94

The flammability characterization and synergistic effects of red phosphorus masterbatch (RPM) with expandable graphite (EG) in flame-retardant polypropylene (PP)/thermoplastic polyurethane (TPU) composites are investigated by limiting oxygen index, UL-94 testing, cone calorimeter tests, thermal gravimetric analysis, Fourier transform infrared (FTIR), and scanning electron microscopy. The results show that the flame retardancy of PP/TPU/EG/RPM composites is greatly influenced by RPM. The synergistic effects between RPM and EG take place in the flame-retardant composites. The presence of RPM with EG decreases significantly the heat release rates and total heat release, and UL-94 V-0 rating is achieved when suitable amount of RPM substitutes for EG in the PP/TPU/EG/RPM composites. The T onset and T 10 wt% of the composites are improved because of the presence of RPM. The FTIR spectra show that the incorporation of RPM improves the thermo-oxidative stability of PP/TPU at higher temperatures. The morphological observations indicate the reinforcement of thermal stability, and flame-retardant performance is attributed to the compact and stable char layers promoted by RPM with EG acted as an effective heat barrier and thermal insulation.

scholarly journals Various Combinations of Flame Retardants for Poly (vinyl chloride)

2019 ◽  
Vol 17 (1) ◽  
pp. 980-987
Author(s):  
Ayşe Çetin ◽  
S.Gamze Erzengin ◽  
F. Burcu Alp
Keyword(s):  
Flame Retardant ◽  
Flame Retardants ◽  
Synergistic Effects ◽  
Thermal Analyses ◽  
Thermal Characteristics ◽  
Holistic Approach ◽  
Heat Stability ◽  
Softening Temperature ◽  
Zinc Borate ◽  
Limiting Oxygen Index

AbstractVarious combinations of zinc borate (ZB), alumina trihydrate (ATH) and magnesium hydroxide (MH) were used to retard the flammability of PVC composite. Flame retardancy of samples were investigated with limiting oxygen index (LOI) test. Further testing was achieved to expose the individual and synergistic effects of flame retardant additives on heat stability, Vicat softening temperature, fusion time, microstructure, mechanical and thermal characteristics. Microstructural and thermal analyses were performed by scanning electron microscopy and TG/DTA respectively. The LOI results showed that, high levels of ZB-ATH combination provided the highest LOI value of 53.4%. Although ZB and its combinations improved the fire performances of composites, they caused a small reduction at tensile strengths. When compared with plain PVC, flame retardant composites had better thermal stability. In addition to the advantages of ZB, when test results were evaluated with a holistic approach ZB-ATH-MH combination was understood to be an effective flame retardant alternative with this research.

Modified expandable graphite as an effective flame retardant for LLDPE/EVA composites filled with Mg(OH)2/Al(OH)3

2019 ◽  
Vol 33 (7) ◽  
pp. 938-955
Author(s):  
Nian Liu ◽  
Na Wang ◽  
Lingtong Li ◽  
Weidi He ◽  
Jianbing Guo ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Synergistic Effects ◽  
Ethylene Vinyl Acetate ◽  
Gas Production ◽  
Expandable Graphite ◽  
Limiting Oxygen Index ◽  
Cone Calorimeter Test ◽  
Ul 94

The flammability, thermal properties, and synergistic effects of modified expandable graphite (MEG) with magnesium hydroxide (MH) and aluminum hydroxide (ATH) on the linear low-density polyethylene/ethylene vinyl acetate (LLDPE/EVA) blends are investigated by Underwriters Laboratories-94 (UL-94) vertical combustion test, limiting oxygen index (LOI), thermogravimetric analysis (TGA), cone calorimeter test (CCT), and scanning electron microscopy (SEM). The results show that the MEG improves the flame-retardant efficiency of LLDPE/EVA blends. The addition of MEG apparently improves the LOI values and the UL-94 rating of LLDPE/EVA composites. The data obtained from the CCT show that the heat release rate (HRR), the total heat release (THR), and the gas production rate of composites with MEG decrease remarkably with increasing the content of MEG. When 10 phr of MEG is added, the char residues of LEMEG10 increase to 38.2% from 2.7% of LLDPE/EVA. The results of SEM and CCT present that MEG can improve the quality of char layers. The rate of char formation is enhanced also due to the existence of MEG, which plays an important role to improve the flame retardancy of the LLDPE/EVA composites.

scholarly journals Synergistic Effects and Mechanism of Modified Silica Sol Flame Retardant Systems on Silk Fabric

Materials ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 1842 ◽  
Author(s):  
Chun Liu ◽  
Tieling Xing ◽  
Bingju Wei ◽  
Guoqiang Chen
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Industrial Development ◽  
Flame Retardants ◽  
Synergistic Effects ◽  
Silica Sol ◽  
Gas Chromatography Mass Spectrometry ◽  
Silk Fabric ◽  
Endothermic Reaction ◽  
Limiting Oxygen Index

The nano-silica sol was prepared by sol-gel method, and the boric acid, urea, cyanoguanidine, melamine cyanurate (MCA), 1-hydroxyethane 1,1-diphosphonic acid (HEDP), and 6H-dibenz (C,E) (1,2) oxaphosphorin-6-oxide (DOPO) were added to the silica sol to modify the flame retardant through physical doping and chemical bonding. According to the formula proposed by Lewin, the calculation of flammability parameters were obtained by the limiting oxygen index meter, the micro calorimeter, the vertical burner, and the thermogravimetric analyzer proved that there was a synergistic or additive effect between the B/N/P flame retardant and the silica sol. Fourier transform infrared (FT-IR) spectrum, scanning electron microscopy, and pyrolysis gas chromatography-mass spectrometry were used to characterize the morphology, structure, and pyrolysis products of treated silk fabric and residues after combustion. The results show that the flame retardancy of silica-boron sol is mainly caused by endothermic reaction and melt covering reaction. Silicon-nitrogen sol acts as a flame retardant through endothermic reaction, release of gases, and melting coverage. Silicon-phosphorus sol achieves flame retardancy by forming an acid to promote formation of a carbon layer and melting coverage. Silica sol and other flame retardants show excellent flame retardanty after compounding, and have certain complementarity, which can balance the dosage, performance, and cost of flame retardants, and is more suitable for industrial development.

Study of Synergistic Effects of Cerium Oxide on Intumescent Flame Retardant Polypropylene System

2014 ◽  
Vol 887-888 ◽  
pp. 90-93
Author(s):  
Ya Li Wang ◽  
Xiao Ping Tang ◽  
Xu Dong Tang
Keyword(s):  
Flame Retardant ◽  
Cerium Oxide ◽  
Synergistic Effects ◽  
Intumescent Flame Retardant ◽  
Limiting Oxygen Index ◽  
Reasonable Amount ◽  
Melamine Salt ◽  
Impact Tester ◽  
Synergistic Agent ◽  
Pendulum Impact

Melamine salt of pentaerythritol phosphate (PPM) was synthesized with phosphoric acid, pentaerythritol and melamine. This flame retardant polypropylene containing cerium oxide (CeO2) can be used as a synergistic agent for the flame retardancy of intumescent flame retardant polypropylene system. The pendulum impact tester and universal material machine were used to evaluate the mechanical properties of intmescent flame retardant system, the limiting oxygen index (LOI), thermogravimetric analysis (TGA) and scanning electron microscopy (SEM) were used to evaluate the synergistic effects of CeO2. The LOI value of the system increased when reasonable amount of CeO2 was added, and it reached maximum (30%) when the mass fraction of PPM was 20% and CeO2 added was 1% of the PPM/PP system. The TGA data shows that CeO2 can enhance the thermal stability of the intumescent flame retardant polypropylene system at high temperature and effectively increase the char residue formation. The morphological structures observed with SEM demonstrate that reasonable amount of CeO2 can improve the morphologies of intumescent char layer and the properties of heat insulation and barrier material. The reasonable amount of CeO2 in the system can increase its impact strength and decrease its tensile properties.

scholarly journals A Study on Circular Economy Material Using Fish Scales as a Natural Flame Retardant and the Properties of Its Composite Materials

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2446
Author(s):  
Shang-Hao Liu ◽  
Ming-Yuan Shen ◽  
Cheng-You Yang ◽  
Chin-Lung Chiang
Keyword(s):  
Thermal Properties ◽  
Flame Retardant ◽  
Circular Economy ◽  
Synergistic Effects ◽  
Matrix Material ◽  
Polymer Materials ◽  
Fish Scales ◽  
Char Residue ◽  
Pyrolysis Kinetics ◽  
Limiting Oxygen Index

Fish scales (FSs) are fishery wastes that can cause environmental pollution. This study aimed to solve this environmental problem. FSs were used as a flame retardant for polymer materials, making them valuable. Fish scales were combined with a commercial flame retardant, ammonium polyphosphate (APP), through synergistic effects to reduce the amount of commercial flame retardant. The use of FSs conforms to the concept of a circular economy and lowers costs by reducing the consumption of APP. Thermogravimetric analysis (TGA), integral procedural decomposition temperature (IPDT), pyrolysis kinetics, limiting oxygen index (LOI), the Underwriters Laboratories 94 (UL94) flammability test, scanning election microscopy, Raman spectroscopy, and energy-dispersive X-ray spectroscopy were used to determine the thermal properties, flame retardant properties, flame retardant mechanism, char morphology, and composition of the composites. The TGA results indicated that the addition of 40% flame retardant raised the char residue from 16.45 wt.% (pure EP) to 36.07 wt.%; IPDT from 685.6 °C (pure EP) to 1143.1°C; LOI from 21% (pure EP) to 30%; and UL94 classification from fail (pure EP) to V-0. These results suggest an increase in char residue, which indicates better protection of the polymer matrix material. The improvements in IPDT, LOI, and UL94 classification, which indicate greater thermal stability, lower flammability (from flammable to fireproof), and higher flammability rating (from fail to V-0), respectively, suggest that the composite material has favorable thermal properties and is less inflammable.

Physical and bacterial processes affecting suspended particulate matter in a tidal river

1998 ◽  
Vol 38 (6) ◽  
pp. 327-335
Author(s):  
Yasunori Kozuki ◽  
Yoshihiko Hosoi ◽  
Hitoshi Murakami ◽  
Katuhiro Kawamoto
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Suspended Particulate Matter ◽  
River Mouth ◽  
Tidal River ◽  
Natural Soil ◽  
Size Change ◽  
Run Off ◽  
Suspended Particulate ◽  
And Behavior

In order to clarify the origin and behavior of suspended particulate matter (SPM) in a tidal river, variation of SPM in a tidal river was investigated with regard to its size and constituents. SPM was separated into three groups according to size. Change of contents of titanium and organic substances of each group of SPM was examined. SPM which was discharged by run-off was transported with decomposition and sedimentation in a tidal river. Concentration of SPM with a particle size greater than 0.45 μm increased due to resuspension in a tidal river. Origin of SPM with a size of less than 0.45 μm at upstream areas was from natural soil and most of such SPM which had been transported settled near a river mouth. It was determined from examination of the CN ratio and the ratio of the number of attached bacteria to free bacteria that SPM with a size greater than 1.0 μm at upstream areas was decomposing intensively. At the downstream areas, SPM with a size of less than 0.45 μm came from the sea. SPM with particle size greater than 1.0 μm consisted of plankton and substances which were decomposed sufficiently while flowing.

Preparation and Characterization of Soybean Oil-based Flame Retardant Rigid Polyurethane Foams Containing Phosphaphenanthrene Groups

2020 ◽  
Vol 17 (10) ◽  
pp. 760-771
Author(s):  
Qirui Gong ◽  
Niangui Wang ◽  
Kaibo Zhang ◽  
Shizhao Huang ◽  
Yuhan Wang
Keyword(s):  
Soybean Oil ◽  
Flame Retardant ◽  
Chemical Structure ◽  
Cell Structure ◽  
Polyurethane Foams ◽  
Limiting Oxygen Index ◽  
Rigid Polyurethane Foams ◽  
Degradation Activation Energy ◽  
Ft Ir

A phosphaphenanthrene groups containing soybean oil based polyol (DSBP) was synthesized by epoxidized soybean oil (ESO) and 9,10-dihydro-oxa-10-phosphaphenanthrene-10-oxide (DOPO). Soybean oil based polyol (HSBP) was synthesized by ESO and H2O. The chemical structure of DSBP and HSBP were characterized with FT-IR and 1H NMR. The corresponding rigid polyurethane foams (RPUFs) were prepared by mixing DSBP with HSBP. The results revealed apparent density and compression strength of RPUFs decreased with increasing the DSBP content. The cell structure of RPUFs was examined by scanning electron microscope (SEM) which displayed the cells as spherical or polyhedral. The thermal degradation and flame retardancy of RPUFs were investigated by thermogravimetric analysis, limiting oxygen index (LOI), and UL 94 vertical burning test. The degradation activation energy (Ea) of first degradation stage reduced from 80.05 kJ/mol to 37.84 kJ/mol with 80 wt% DSBP. The RUPF with 80 wt% DSBP achieved UL94 V-0 rating and LOI 28.3. The results showed that the flame retardant effect was mainly in both gas phase and condensed phase.

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