scholarly journals Enhancement of Flame Retardancy of Colorless and Transparent Semi-Alicyclic Polyimide Film from Hydrogenated-BPDA and 4,4′-oxydianiline via the Incorporation of Phosphazene Oligomer

Polymers ◽  
2020 ◽  
Vol 12 (1) ◽  
pp. 90
Author(s):  
Xiao Wu ◽  
Ganglan Jiang ◽  
Yan Zhang ◽  
Lin Wu ◽  
Yanjiang Jia ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Composite Films ◽  
Optical Transmittance ◽  
Polyimide Film ◽  
Total Heat Release ◽  
Limiting Oxygen Index ◽  
Biphenyltetracarboxylic Dianhydride ◽  
Thermal Stability Of

Enhancement of flame retardancy of a colorless and transparent semi-alicyclic polyimide (PI) film was carried out by the incorporation of phosphazene (PPZ) flame retardant (FR). For this purpose, PI-1 matrix was first synthesized from hydrogenated 3,3′,4,4′-biphenyltetracarboxylic dianhydride (HBPDA) and 4,4′-oxydianiline (ODA). The soluble PI-1 resin was dissolved in N,N-dimethylacetamide (DMAc) to afford the PI-1 solution, which was then physically blended with PPZ FR with the loading amounts in the range of 0–25 wt.%. The PPZ FR exhibited good miscibility with the PI-1 matrix when its proportion was lower than 10 wt.% in the composite films. PI-3 composite film with the PPZ loading of 10 wt.% showed an optical transmittance of 75% at the wavelength of 450 nm with a thickness of 50 μm. More importantly, PI-3 exhibited a flame retardancy class of UL 94 VTM-0 and reduced total heat release (THR), heat release rate (HRR), smoke production rate (SPR), and rate of smoke release (RSR) values during combustion compared with the original PI-1 film. In addition, PI-3 film had a limiting oxygen index (LOI) of 30.9%, which is much higher than that of PI-1 matrix (LOI: 20.1%). Finally, incorporation of PPZ FR decreased the thermal stability of the PI films. The 10% weight loss temperature (T10%) and the glass transition temperature (Tg) of the PI-3 film were 411.6 °C and 227.4 °C, respectively, which were lower than those of the PI-1 matrix (T10%: 487.3 °C; Tg: 260.6 °C)

Epoxy resin/cyanate ester composites containing DOPO and wollastonite with simultaneously improved flame retardancy and thermal resistance

2020 ◽  
Vol 32 (6) ◽  
pp. 710-718
Author(s):  
Zhengzhou Wang ◽  
Xin Gao ◽  
Wenfeng Li
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Thermal Studies ◽  
Cyanate Ester ◽  
Total Heat Release ◽  
Limiting Oxygen Index ◽  
Peak Heat Release Rate ◽  
Ul 94

Flame-retardant epoxy (EP) resin/cyanate ester (CE) composites were prepared with 9,10-dihydro-9-oxa-10-phosphaphenanthrene 10-oxide (DOPO) and wollastonite (Wo). The combustion behavior of the flame-retardant EP/CE composites was investigated by limiting oxygen index (LOI), UL-94, and cone calorimeter tests. It is found that the EP/CE composite containing 7 wt% DOPO and 3 wt% Wo (sample 7DO/3Wo/EP/CE) exerts the best flame retardancy (LOI 35.5% and UL-94 V-0 rating). The peak heat release rate and total heat release of sample 7DO/3Wo/EP/CE increase slightly, while total smoke release decreases about 14% compared with the EP/CE composite containing 10 wt% DOPO (sample 10DO/EP/CE). Thermal studies indicate that the glass transition temperature and temperature at 5% mass loss of sample 7DO/3Wo/EP/CE are higher than that of sample 10DO/EP/CE. Moreover, the mechanical properties of EP/CE composites were investigated.

scholarly journals Investigations of the Montmorillonite and Aluminium Trihydrate Addition Effects on the Ignitability and Thermal Stability of Asphalt

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Kai Zhu ◽  
Ke Wu ◽  
Bin Wu ◽  
Zhiyi Huang
Keyword(s):  
Heat Release ◽  
Heat Release Rate ◽  
Release Rate ◽  
Cone Calorimeter ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Modified Montmorillonite ◽  
Organically Modified Montmorillonite ◽  
Organically Modified ◽  
Thermal Stability Of

By means of limiting oxygen index (LOI), cone calorimeter, and TG-DSC tests, this paper investigated the effect of unmodified montmorillonite (MMT), organically modified montmorillonite (OMMT), and aluminium trihydrate (ATH) additions on the flame retardancy for asphalt combustion. Experimental results showed that adding a small amount of montmorillonite did not significantly increase the oxygen index of the asphalt but reduced the heat release rate during asphalt combustion. TGA tests had indicated that the montmorillonite (MMT and OMMT) could suppress the release of flammable volatiles and form more asphaltenes, which hence postponed the burnout time of asphalt. Furthermore, the combination of montmorillonite (MMT and OMMT) and ATH had yielded a synergistic effect, which had further reduced the heat release rate and also increased the oxygen index of asphalt. In particular, after further addition of OMMT, the barrier layer showed less crack, leading to a significant decrease in the heat release rate as compared to the adding of ATH alone.

Flame Retardant Epoxy Resin Containing Magnesium Phosphinate

2013 ◽  
Vol 634-638 ◽  
pp. 1927-1930 ◽  
Author(s):  
Jia Chen ◽  
Ji Yan Liu ◽  
Xue Qing Liu ◽  
Shan Sun
Keyword(s):  
Flame Retardant ◽  
Epoxy Resin ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Limiting Oxygen Index ◽  
Gas Source ◽  
Char Formation ◽  
Higher Temperature ◽  
Preliminary Study ◽  
Thermal Stability Of

In this paper, magnesium methylcyclohexylphosphinate (Mg(MHP)) was used as flame retardant for epoxy resin(EP).The flame retardancy and thermal stability of Mg(MHP)/EP composites have been studied. As a result, the composite with 20-25% Mg(MHP) can achieve the satisfying flame retardancy with the limiting oxygen index (LOI) of 29.05 % and passing the UL-94 V-0 rating. TG results showed that adding Mg(MHP) into EP leads to a increase in the onset temperature of degradation and depresses the thermal decomposition below around 470 °C. Beyond 470 °C, the residue char of the composites lost more quickly compared to neat EP. A preliminary study seem to conclude that Mg(MHP) acts as the condensed source by promoting the char formation below around 470 oC and as the gas source by vaporizing at higher temperature.

Self-assembled bio-based coatings for flame-retardant and antibacterial polyester–cotton fabrics

2021 ◽  
pp. 004051752110351
Author(s):  
Zhenlin Jiang ◽  
Youxian Hu ◽  
Keyu Zhu ◽  
Yue Li ◽  
Chaosheng Wang ◽  
...  
Keyword(s):  
Heat Release ◽  
Flame Retardant ◽  
Antibacterial Effect ◽  
Oxygen Index ◽  
Cotton Fabrics ◽  
Layer By Layer ◽  
Total Heat Release ◽  
Limiting Oxygen Index ◽  
Degradation Temperature ◽  
Single Function

There are many defects in the post finishing flame-retardant modification of polyester–cotton (CT) fabric, leading to shortcomings such as single function and low flame-retardant efficiency, which still need to be solved urgently. Herein, a bio-based flame-retardant and antibacterial coating consisting of phytic acid and DL-arginine was deposited on CT fabrics using layer-by-layer assembly to obtain a flame-retardant and antibacterial CT fabric. Fourier transform infrared spectroscopy confirmed that the assembled coating was successful deposited on the CT fabric. The thermogravimetric analysis revealed that the number of bilayers had no significant effect on the degradation temperature of the coated CT fabric; however, it significantly improved the charring effect of the sample, wherein the char rate of the CT fabric coated with 20 bilayers increased from 0.11 to 8.67 wt% compared with uncoated CT fabric at 700°C. In addition, the limiting oxygen index of the CT fabric coated with 20 bilayers increased to 32.0 ± 0.3%. Furthermore, the vertical results revealed that the CT fabric coated with five bilayers attained the UL-94 V-1 grade. The heat release rate (HRR) and the total heat release (THR) of the coated CT fabric were significantly decreased compared to those of the uncoated CT fabric. In particular, the HRR and THR of the CT fabric coated with five bilayers reduced by 28.97% and 30.49%, respectively. Furthermore, the coated CT fabric exhibited an obvious antibacterial effect on Staphylococcus aureus, and the inhibitory ring increased from 0 to 4.0 mm with an increase in bilayers to 20. This study describes a facile method of flame-retardant and antibacterial modification of CT fabric using biological materials.

scholarly journals Research on the Flame Retardancy Properties and Mechanism of Modified Asphalt with Halloysite Nanotubes and Conventional Flame Retardant

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4509
Author(s):  
Yangwei Tan ◽  
Zhaoyi He ◽  
Xiang Li ◽  
Bin Jiang ◽  
Jiaqi Li ◽  
...  
Keyword(s):  
Synergistic Effect ◽  
Heat Release ◽  
Barrier Layer ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Halloysite Nanotubes ◽  
Limiting Oxygen Index ◽  
Modified Asphalt ◽  
Flame Retardancy Mechanism

The inflammability of asphalt road will promote fire spread in the tunnel and produce lots of toxic smoke. To improve the fire resistance of asphalt pavement, mineral powder flame retardants are generally replaced by flame retardants in equal amounts. In this study, the effects of the synergistic flame retardancy system of halloysite nanotubes (HNTs) and conventional flame retardants (CFR) on the flame retardancy performance and mechanism of asphalt were investigated. Firstly, the flame retardancy properties of the HNTs and CFR composite modified asphalt were investigated based on the Cleveland open cup method (COC), Limiting oxygen index meter (LOI), and Cone calorimeter tests (CCTs). Then, the flame retardancy mechanism of the modified asphalt was studied based on Thermogravimetric analyzer (TGA), Fourier-transform infrared (FTIR), and Scanning electron microscopy (SEM). The results show that adding HNTs could improve the flame retardancy of the CFR modified asphalt binder. When 1 wt % HNTs and 8 wt % CFR were used, the limiting oxygen index of asphalt increased by 40.1%, the ignition temperature increased by 40 °C, while the heat release rate, total heat release, the smoke production rate, total smoke release, and other parameters decreased with varying degrees. Based on TG, FTIR, and SEM, the targeted flame retardancy mechanism and synergistic effect of HNTs/CFR flame retardancy system were revealed and summarized as three stages: (1) Stage 1, aluminum hydroxide (ATH) absorbs heat through thermal decomposition and inhibits the decomposition of lightweight components in asphalt; (2) Stage 2, aluminum diethyl phosphate (ADP) decomposes and produces organic phosphoric acid, which catalyzes crosslinking and ring thickening of asphalt and the quenching effect of phosphorus free radicals to block the combustion; and (3) Stage 3, HNTs plays an important role in increasing the integrity and density of the barrier layer. In addition, the Al2O3 produced by the decomposition of ATH, the carbon layer formed by the ADP catalyzed pitch, and HNTs play a significant synergistic effect in the formation of the barrier layer. Thus, the combination of HNTs and CFR has been proved to be a prospective flame retardancy system for asphalt.

scholarly journals Synergistic Effects of Ladder and Cage Structured Phosphorus-Containing POSS with Tetrabutyl Titanate on Flame Retardancy of Vinyl Epoxy Resins

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1363
Author(s):  
Xu Han ◽  
Xiaohua Zhang ◽  
Ying Guo ◽  
Xianyuan Liu ◽  
Xiaojuan Zhao ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Heat Release ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Tetrabutyl Titanate ◽  
Thermal Stabilities ◽  
Limiting Oxygen Index ◽  
Char Layer ◽  
Smoke Production ◽  
Phosphorus Containing

The cage and ladder structured phosphorus-containing polyhedral oligomeric silsesquioxanes (DOPO-POSS) have been synthesized through the hydrolytic condensation of 9,10-dihydro-9-oxa-10-phosphenanthrene-10-oxide (DOPO)-vinyl triethoxysilane (VTES). The unique ladder and cage–ladder structured components in DOPO-POSS endowed it with good solubility in vinyl epoxy resin (VE), and it was used with tetrabutyl titanate (TBT) to construct a phosphorus-silicon-titanium synergy system for the flame retardation of VE. Thermal stabilities, mechanical properties, and flame retardancy of the resultant VE composites were investigated by thermal gravimetric analysis (TGA), dynamic mechanical analysis (DMA), three-point bending tests, limiting oxygen index (LOI) measurement, and cone calorimetry. The experimental results showed that with the addition of only 4 wt% DOPO-POSS and 0.5 wt% TBT, the limiting oxygen index value (LOI) increased from 19.5 of pure VE to 24.2. With the addition of DOPO-POSS and TBT, the peak heat release rate (PHRR), total heat release (THR), smoke production rate (SPR), and total smoke production (TSP) were decreased significantly compared to VE-0. In addition, the VE composites showed improved thermal stabilities and mechanical properties comparable to that of the VE-0. The investigations on pyrolysis volatiles of cured VE further revealed that DOPO-POSS and TBT exerted flame retardant effects in gas phase. The results of char residue of the VE composites by SEM and XPS showed that TBT and DOPO-POSS can accelerate the char formation during the combustion, forming an interior char layer with the honeycomb cavity structure and dense exterior char layer, making the char strong with the formation of Si-O-Ti and Ti-O-P structures.

Synthesis and characterization of flame-retardant-wrapped carbon nanotubes and its flame retardancy in epoxy nanocomposites

2021 ◽  
pp. 096739112110245
Author(s):  
Jiangbo Wang
Keyword(s):  
Carbon Nanotubes ◽  
Heat Release ◽  
Flame Retardant ◽  
Flame Retardancy ◽  
Total Heat Release ◽  
Pristine Cnts ◽  
Peak Heat Release Rate ◽  
Ep Matrix ◽  
Better Than

A novel phosphorus-silicon containing flame-retardant DOPO-V-PA was used to wrap carbon nanotubes (CNTs). The results of FTIR, XPS, TEM and TGA measurements exhibited that DOPO-V-PA has been successfully grafted onto the surfaces of CNTs, and the CNTs-DOPO-V-PA was obtained. The CNTs-DOPO-V-PA was subsequently incorporated into epoxy resin (EP) for improving the flame retardancy and dispersion. Compared with pure EP, the addition of 2 wt% CNTs-DOPO-V-PA into the EP matrix could achieve better flame retardancy of EP nanocomposites, such as a 30.5% reduction in peak heat release rate (PHRR) and 8.1% reduction in total heat release (THR). Furthermore, DMTA results clearly indicated that the dispersion for CNTs-DOPO-V-PA in EP matrix was better than pristine CNTs.

scholarly journals Effects of collagen fiber addition on the combustion and thermal stability of natural rubber

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Weixing Xu ◽  
Xintao Wu ◽  
Qilin Wen ◽  
Shuangyang Li ◽  
Yongjiao Song ◽  
...  
Keyword(s):  
Natural Rubber ◽  
Flame Retardant ◽  
Nitrogen Content ◽  
Flame Retardancy ◽  
Collagen Fiber ◽  
Oxygen Index ◽  
Air Pockets ◽  
Thermal Stability Of ◽  
Limited Oxygen ◽  
Properties Of Composites

Abstract Collagen fiber (CF) and silane coupling agent-modified collagen fiber (MCF) were used as flame retardant filler for natural rubber (NR) modification. The combustion phenomena and properties of composites blended with different dosages of CF or MCF were compared to elucidate the flame retardant mechanism of the composites. The flame retardancy of NR can be enhanced effectively by increasing nitrogen content (the nitrogen content of CF is about 18%), creating air pockets, and structuring the flame retardant network in the composites. MCF failed to structure a flame retardant network in the composite, indicating that its modification effects of MCF are weaker than those of CF. When CF dosage was 30 wt%, the composite can achieve the best flame retardancy, with limited oxygen index of 29.4% and without smoke and dripping during burning. This study demonstrated a new method for the flame retardant modification of NR. Graphical abstract

scholarly journals Influence of mica mineral on flame retardancy and mechanical properties of intumescent flame retardant polypropylene composites

2021 ◽  
Vol 19 (1) ◽  
pp. 904-915
Author(s):  
Merve Kahraman ◽  
Nilgün Kızılcan ◽  
Mehmet Ali Oral
Keyword(s):  
Synergistic Effect ◽  
Flame Retardancy ◽  
Oxygen Index ◽  
Mechanical Tests ◽  
Efficiency Enhancement ◽  
Cost Performance ◽  
Limiting Oxygen Index ◽  
Polypropylene Composites ◽  
Polymeric Compounds ◽  
Ul 94

Abstract In many plastic applications, improvement of the flame retardancy is a very significant topic. Polypropylene (PP) is used in many applications such as housing industry due to its cost performance efficiency. Enhancement of flame retardancy properties of PP is necessary in many applications. In this study, the investigation focuses on the synergistic effect of mica mineral and IFR in enhancing the flame retardancy properties of PP in order to achieve cost competitive solution, so as to provide that different/various ratios of IFR and mica mineral were added into PP to compose 30 wt% of the total mass of the polymeric compounds. The synergistic effect of mica mineral with IFR in PP was investigated by limiting oxygen index (LOI), glow wire test (GWT), UL-94 test, thermal gravimetric analyses (TGA), and mechanical tests. The results from LOI, UL 94, and GWT tests indicated that mica added to PP/IFR compound has a synergistic flame retardancy effects with the IFR system. When the content of mica was 6 wt%, LOI value of PP compound reaches to 34.9% and becomes V-0 rating (3.2 mm) in UL 94 flammability tests and compounds pass GWT tests both at 750 and 850°C.

The Flammability of Polyacrylonitrile and Its Copolymers I. The Flammability Assessment Using Pressed Powdered Polymer Samples

1993 ◽  
Vol 11 (5) ◽  
pp. 442-456 ◽  
Author(s):  
Jun Zhang ◽  
Michael E. Hall ◽  
A. Richard Horrocks
Keyword(s):  
Flame Retardant ◽  
Flame Retardancy ◽  
Flame Retardants ◽  
Oxygen Index ◽  
Char Residue ◽  
Acrylic Polymer ◽  
Limiting Oxygen Index ◽  
Convenient Means ◽  
Burning Rates ◽  
Polymer Flammability

This paper is the first in a series of four which investigates the burning behaviour and the influence of flame retardant species on the flam mability of fibre-forming polymer and copolymers of acrylonitrile. A pressed powdered polymer sheet technique is described that enables a range of polymer compositions in the presence and absence of flame retardants to be assessed for limiting oxygen index, burning rate and char residue deter minations. The method offers a rapid, reproducible and convenient means of screening possible flame retardant systems, and LOI values compare favourably with those of films and fabrics comprising the same polymeric type. Burning rates, however, are sensitive to changes in physical sample character such as form (film vs. powder sheet) and density. Thus the technique forms an excellent basis for the generation of burning data which will enable comprehensive studies of acrylic polymer flammability and flame retardancy to be undertaken.

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