Types Of Flame Retardants Research Articles

Influence of flame retardant addition on the durability of epoxy based polymer concrete after exposition to elevated temperature

The use of the resin in the civil engineering applications for repair applications, precast elements, etc., was well-developed in the last decade. Polymer concrete (PC) is strongly prescribed for applications where chemical resistance, strength and stiffness are required.When exposed to high temperatures, PC losses significantly its strengths as a consequence of the matrix degradation mainly. Durability concern after exposure to high temperatures is investigated here. A comparison between the physical and mechanical characteristics of an optimized PC before and after adding flame retardant (FR) is undertaken in this study.Mechanical and ultrasonic propagation waves testing were performed on polymer concrete based on epoxy resin with 6, 9, 13 and 16% of resin show that the higher performances are obtained for polymer content of 13%. Two types of FR, consisting on Ammonium Polyphosphate (APP) and aluminium hydroxide (ATH) compounds, are then introduced to this formulation and the three types of concretes were exposed to thermal cycles.Porosity, thermal conductivity and mechanical resistance were measured and their evolution as a function thermal amplitude was studied. It appears that adding ATH improves considerably the mechanical properties of PC vs. Temperature rise. But the second has inversely influence on properties while increasing the effect of temperature.

In situ synthesized and dispersed melamine polyphosphate flame retardant epoxy resin composites

ABSTRACTThe dispersion of flame retardants in polymer matrix has significant impact on the final properties of the final materials. Homogenous dispersion for additive type flame retardant powder in polymer melt or solution with high viscosity is a challenge all the time. In the present research, melamine polyphosphate (MPP) is employed to flame‐retard the epoxy resin (EP). Different from direct addition of MPP powder in viscous EP glue like conventional means, MPP is firstly synthesized by melamine and polyphosphoric acid in a good solvent for EP. Keeping fine and even dispersion of the produced MPP particles, EP prepolymer is added into the MPP containing solution. By this way, perfect dispersion of the flame retardant can be achieved both in the glue and the cured resin. A series of tests such as the particle size analysis, flammability evaluation, and mechanical properties tests are conducted to compare the MPP flame retardant EP obtained by this method and the conventional one. It shows that the in situ synthesis and compounding method can endow the MPP incorporated EP glue system with better homogeneity and stability, hence leading to higher flame retardancy and obviously improved mechanical performance of the final composite. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47194.

Properties of flame‐retardant TPU based on para‐aramid fiber modified with iron diethyl phosphinate

In this paper, a new type of flame retardant (AF‐Fe) based on para‐aramid fiber (AF) which was modified with iron diethyl phosphinate was applied for thermoplastic polyurethane elastomer (TPU). The flame‐retardant properties of TPU were tested using cone calorimeter test, smoke density test, and thermogravimetric analysis/infrared spectrometry. The cone calorimeter test showed that AF‐Fe can greatly reduce the heat release rate, total heat release, smoke factor, and other parameters of TPU composites compared with the sample of TPU/AF. For example, the pHRR of the composite with 1.0 wt% AF‐Fe was reduced by 15.19% compared with the sample with the same content of pure AF. In addition, the smoke factor of TPU/AFFe3 was reduced by 50.52% and 15.63% compared with TPU0 and TPU/AF respectively. The results of smoke density test showed that the luminous flux of TPU/AFFe3 was increased by 79.26% compared with the sample of TPU/AF. The TG results revealed that the sample with TPU/AFFe3 had lower weight loss rate and higher char residue content at 700°C compared with the sample of TPU/AF.

Research progress on flame-retarded silicone rubber

Silicone rubber (SR) is widely used for its excellent temperature resistance, weathering resistance, chemical resistance and good transparence. In order to improve the flame retardancy of SR, many types of flame retardants (FRs) have been investigated. This paper summarized the research progress on flame-retarded SR, introduced different types of FRs for SR, analyzed the mechanisms of FR in condensed and gas phase, and finally predicted the prospective of flame-retarded SR.

Changes in Flame Retardant and Legacy Contaminant Concentrations in Indoor Air during Building Construction, Furnishing, and Use.

A newly constructed university building was selected for targeted assessment of changes in the levels of flame retardants and legacy contaminants during the installation of building equipment, furniture, electronics, and first year of building use. Indoor air samples were collected during several periods of intensive equipment installation to determine a relationship between newly introduced equipment and changes in the concentrations and profiles of contaminants in indoor air. Samples were analyzed for polybrominated diphenyl ethers (PBDEs), hexabromocyclododecanes (HBCDDs), and new types of flame retardants: brominated (BFRs) and organophosphate esters (OPEs). Additionally, typical outdoor contaminants such as polychlorinated biphenyls (PCBs) and organochlorine pesticides (OCPs) were also analyzed for comparison. From the set of 90 compounds analyzed here, hexabromobenzene (HBB) and tris(2-chloroisopropyl)phosphate (TCIPP) showed a significant concentration increase in indoor air concentrations during computer installation and operation, suggesting emission by operating computers, while an order of magnitude concentration increase in tris(1,3-dichloro-2-propyl)phosphate (TDCIPP) and tri-m-cresyl phosphate (TMTP) was observed after the furniture and carpet was introduced to the computer room, suggesting furniture or carpet as a source. However, the majority of compounds had no systematic change in concentrations during equipment installation, indicating that no sources of target compounds were introduced or, that source introduction was not reflected in indoor air concentrations. Generally, low levels of legacy flame retardants compared to their novel alternatives were observed.

Effects of nitrogen-phosphorus flame retardants in different forms on the performance of slim-type medium-density fiberboard

An orthogonal design was used to optimize the process of making slim medium-density fiberboard modified by a nitrogen-phosphorous series of flame retardants. Mechanical performance was the evaluating criterion. Subsequently, the combustion performances of each type of flame retardant, including in states solid, liquid, and their combination with a ratio of 1:1, were investigated to clarify the corresponding fire-retardant mechanism. The results showed that only physical bonding was responsible for connecting the wood fiber with the retardants, according to the Fourier transform infrared spectrum. Catalytic charring, flame retardancy, and the thermal insulation of three types of retardant were solidified by the results of a cone calorimeter (CONE) analysis, thermogravimetric (TG) analysis, and differential scanning calorimetry (DSC), and the mixture of solid and liquid was demonstrated as the primary choice. It was also found that after the mixture of the solid and liquid retardant was added, the limiting oxygen index of the board reached 43.3%, and it met the requirements of the B1 Class in the Chinese National Standard GB/T8624-2012 (2012).

Emerging and legacy flame retardants in indoor dust from East China

To understand human exposure to dust-associated flame retardants in the biggest metropolitan area (city of Shanghai) of East China, our study determined a suite of legacy and emerging flame retardants in dust from dwellings, cars, and university computer labs. The results exhibited a consistent dominance of organophosphate flame retardants (OPFRs) over polybrominated diphenyl ethers (PBDEs) and other alternative flame retardants (AFRs) regardless of microenvironments. In addition to OPFRs, some alternative flame retardants, such as decabromodiphenyl ethane (DBDPE), 2-ethylhexyltetrabromobenzoate (EH-TBB), bis(2-ethylhexyl)-3,4,5,6-tetrabromobenzoate (BEH-TEBP), and 1,2-bis(2,4,6-tribromophenoxy)ethane (BTBPE), were also frequently detected. Among them, DBDPE exhibited concentrations comparable to those of PBDEs. Comparison with international studies indicated that concentrations of ∑PBDEs (0.2–12.3 μg/g dry weight or dw) and ∑OPFRs (3.8–165.5 μg/g dw) from Shanghai dwellings (bedroom and living room) were generally in the middle of concentration ranges reported worldwide, whereas elevated DBDPE concentrations (0.1–9.5 μg/g dw) was observed compared with most other countries or regions. OPFR compositions in house dust from this study also differed from those from many other countries. This suggested inter-regional differences in market demands on the quantities and types of flame retardants. Human intake estimation suggested elevated exposure for toddlers when compared with adults, although the daily intake estimations of individual flame retardants were generally 2–4 orders of magnitude lower than the reference doses. The findings from this preliminary study developed a baseline for future evaluation of the sources and fate of emerging flame retardants and related human exposure risks in East China.

Compact ( $\lambda /45$ -Sized) Electromagnetic Bandgap Structures With Stacked Open-Circuit Lines

This letter introduces double layer layouts of open-circuit lines into the electromagnetic bandgap (EBG) structures to enable changing the shunt circuit of the parallel plate waveguide to inductance in compact spaces. That is, compact EBG structures were achieved. The EBG structures, fabricated using standard fabrication processes and using a low-cost substrate (flame retardant type 4), enable a 1-mm-order size for a 2.4-GHz BG. The size is less than 1/10 of the conventional mushroom structures and corresponds to 1/45 of a substrate wavelength. This compact as well as low-cost EBG structure is promising for noise suppression applications of power distribution networks, especially for wireless products with high-density circuit boards.

Study on the Rheological Behaviour of Sisal Fibre/HDPE Composites with Flame Retardant

The rheological behaviour of sisal fibre/HDPE composites containing two types of flame retardants as magnesium hydroxide and ammonium polyphosphate was studied using a capillary rheometer. The mass ratio of HDPE to sisal fibre was set as 20 phr. Flame retardants were added at 10, 20 and 30 phr. Results showed that the composites exhibited pseudoplastic behaviour as the shear viscosity decreased with increasing shear rate. Shear stress and real shear viscosity increased with increasing flame retardant, with magnesium hydroxide giving higher values than ammonium polyphosphate. Therefore, magnesium hydroxide had a marked effect on the processing power, while ammonium polyphosphate did not greatly affect the shear viscosity of the composites. An increase in elongation rate reduced the elongation viscosity. The flame retardant contents had no significant effect on the elongation viscosity at high elongation rate. The materials showed increased extrudate swell with increasing apparent shear rate, but this significantly decreased with the addition of flame retardant. The power law index (n) for all composites was less than 1 and the flow consistency index K was higher for composites with flame retardant than those without. Moreover, magnesium hydroxide was more effective than ammonium polyphosphate causing an increase in the K value.

Flame Retardancy of Carbon Fibre Reinforced Sorbitol Based Bioepoxy Composites with Phosphorus-Containing Additives.

Carbon fibre reinforced flame-retarded bioepoxy composites were prepared from commercially available sorbitol polyglycidyl ether (SPE) cured with cycloaliphatic amine hardener. Samples containing 1, 2, and 3% phosphorus (P) were prepared using additive type flame retardants (FRs) resorcinol bis(diphenyl phosphate) (RDP), ammonium polyphosphate (APP), and their combinations. The fire performance of the composites was investigated by limiting oxygen index (LOI), UL-94 tests, and mass loss calorimetry. The effect of FRs on the glass transition temperature, and storage modulus was evaluated by dynamic mechanical analysis (DMA), while the mechanical performance was investigated by tensile, bending, and interlaminar shear measurements, as well as by Charpy impact test. In formulations containing both FRs, the presence of RDP, acting mainly in gas phase, ensured balanced gas and solid-phase mechanism leading to best overall fire performance. APP advantageously compensated the plasticizing (storage modulus and glass transition temperature decreasing) effect of RDP in combined formulations; furthermore, it led to increased tensile strength and Charpy impact energy.

Preparation and properties of an efficient smoke suppressant and flame‐retardant agent for thermoplastic polyurethane

APP@ETA, as a new type of flame retardant, was prepared by chemically modifying ammonium polyphosphate (APP) with ethanolamine (ETA) and applied to thermoplastic polyurethane (TPU) in this study. Then, the smoke suppression properties and flame‐retardant effects of APP@ETA in TPU composites were evaluated using smoke density test, cone calorimeter test, etc. And, the thermal degradation properties of flame‐retardant TPU composites were investigated by thermogravimetric analysis/infrared spectrometry. The smoke density test results indicated that APP@ETA could obviously improve the luminous flux of TPU composites in the test with or without flame. The cone calorimeter test results showed that total smoke release, smoke production rate and smoke factor of the composites with APP@ETA were significantly decreased than those of the composites with APP. For example, when the loading of APP@ETA or APP was 12.5 wt%, the total smoke release of the sample with APP@ETA decreased to 3.5 m2/m2 from 6.0 m2/m2, which was much lower than that of the sample with APP, reduced by 41.7%. The thermogravimetric analysis results demonstrated that APP@ETA could decrease the initial decomposition temperature and improve the thermal stability at high temperature for TPU composites. Copyright © 2017 John Wiley & Sons, Ltd.

Highly Effective Flame Retardancy of a Novel DPPA-Based Curing Agent for DGEBA Epoxy Resin

The flame retardancy, thermal, and mechanical properties of the cured epoxy resins are difficult to be simultaneously improved. In the present work, a novel DPPA-based curing agent, 10-[(4-hydroxyphenyl)(4-hydroxyphenylimino)methyl]-5,10-dihydrophenophosphazine 10-oxide (H-DPPA), is successfully synthesized to serve as a co-curing agent of 4, 4′-diaminodiphenylmethane (DDM) for bisphenol A diglycidyl ether (DGEBA) epoxy resin. With the aid of 3.0 wt % of H-DPPA, the cured epoxy resin, in which the phosphorus content is as low as 0.22%, passes V-0 rating of UL-94 test with limiting oxygen index (LOI) of 31.8%. The high flame retardancy of epoxy resin modified by H-DPPA originated mainly from the formation of intumescent char layer during combustion. This new type of flame retardant containing both phosphine oxide structure and nitrogen moieties provides epoxy resins with excellent integrated performances.

Results from Screening Polyurethane Foam Based Consumer Products for Flame Retardant Chemicals: Assessing Impacts on the Change in the Furniture Flammability Standards.

Flame retardant (FR) chemicals have often been added to polyurethane foam to meet required state and federal flammability standards. However, some FRs (e.g., PBDEs and TDCIPP) are associated with health hazards and are now restricted from use in some regions. In addition, California’s residential furniture flammability standard (TB-117) has undergone significant amendments over the past few years, and TDCIPP has been added to California’s Proposition 65 list. These events have likely led to shifts in the types of FRs used, and the products to which they are applied. To provide more information on the use of FRs in products containing polyurethane foam (PUF), we established a screening service for the general public. Participants residing in the US were allowed to submit up to 5 samples from their household for analysis, free of charge, and supplied information on the product category, labeling, and year and state of purchase. Between February 2014 and June 2016, we received 1141 PUF samples for analysis from various products including sofas, chairs, mattresses, car seats and pillows. Of these samples tested, 52% contained a FR at levels greater than 1% by weight. Tris(1,3-dichloroisopropyl)phosphate (TDCIPP) was the most common FR detected in PUF samples, and was the most common FR detected in all product categories. Analysis of the data by purchasing date suggests that the use of TDCIPP decreased in recent years, paralleled with an increase in the use of TCIPP and a nonhalogenated aryl phosphate mixture we call “TBPP.” In addition, we observed significant decreases in FR applications in furniture products and child car seats, suggesting the use of additive FRs in PUF may be declining, perhaps as a reflection of recent changes to TB-117 and Proposition 65. More studies are needed to determine how these changes in FR use relate to changes in exposure among the general population.

The Cause of Whitening by Flame Retardants Treatment on Korean Wooden Cultural Heritage

Korean wooden cultural heritages are treated by flame retardants to protect fire hazards. Two types of flame retardants are used to treat wooden cultural heritage. These flame retardants cause some problems such as surface whitening, discoloration, and cracks due to the chemical reaction caused by Korean traditional wood painting (Dancheong), flame retardant and wood humidity. The Korean government is trying to cut down on the amount of flame retardants for the wooden cultural heritage because of these problems. This study was carried out to find the cause of whitening by flame retardants treatment. The reaction between pigment and flame retardant chemicals was analyzed by infrared spectroscopy.

Synthesis of a novel phosphorus-nitrogen type flame retardant composed of maleimide, triazine-trione, and phosphaphenanthrene and its flame retardant effect on epoxy resin

In this paper, a novel phosphorus/nitrogen-containing compound (DMT) constructed by maleimide, phosphaphenanthrene and triazine-trione was successfully synthesized. The chemical structure of DMT was characterized by Fourier transform infrared spectroscopy (FTIR), 1H and 31P nuclear magnetic resonance (NMR). DMT was then blended with diglycidyl ether of bisphenol-A (DGEBA) to prepare a series of flame-retardant epoxy resins. The flame retardancy and combustion behavior were evaluated using limited oxygen index (LOI), vertical burning (UL94) and cone calorimeter test. The results indicated that DMT dramatically enhanced the flame retardancy of epoxy resin. When the phosphorus content was only 1.0%, the EP/DMT-1.0 sample had a LOI value of 35.8%, and achieved UL94 V-0 rating. The combustion parameters disclosed that DMT obviously weakened the heat release intensity. Compared with the neat EP sample, the peak of heat release rate (pk-HRR), average of heat release rate (av-HRR) and total heat release (THR) of EP/DMT-1.25 sample were decreased by 59.4%, 28.2% and 27.4%, respectively. The decreased av-EHC of EP/DMT thermosets indicated that DMT inhibited the gaseous phase combustion due to the gaseous phase quenching effect of phosphorus-containing free radicals derived from the decomposed DOPO group. The condensed phase studies indicated that DMT promoted the charring of EP matrix and formation of phosphorus-containing char layer with compact and intumescent structure. DMT exerted bi-phase flame retardant effect.

The Effects of Graphene and Flame Retardants on Flammability and Mechanical Properties of Natural Fibre Reinforced Polymer Composites

The effects of incorporating three different types of flame retardant (FR) and two variants of graphene into 10 %wt palm EFB natural fibre (NF) filled epoxy composites were investigated in term of the flammability, thermal and mechanical properties through standard Bunsen burner experiment, bomb calorimetry, TGA and tensile tests. The types of FR employed include zinc borate (ZB), ammonium polyphosphate (APP) and alumina trihydrate (ATH) while a lab synthesised and a commercial form of graphene were used in the current work. Compared to the neat NF filled epoxy composite, specimens loaded with 15 %wt of either ZB or APP demonstrated a drip-free condition as observed from the Bunsen burner tests, which could be attributed to the strong char forming characteristic of the compositions. In specimens containing 15 %wt of either ZB or ATH, results from Bomb calorimetry revealed that these specific formulations produced the lowest mean gross heat release amongst others, suggesting better resistant to flame. Relative to the graphene incorporated composites, the post TGA measured mass residue was observed to be greater in FR rich formulations, suggesting that FR additives capable of yielding a much superior flame retardancy compared to graphene. While a slight increases in Young’s modulus was recorded in composites loaded with FR, such formulations produced several main drawbacks whereby reduction in ultimate tensile strength and elongation to break were being measured in large proportion of the specimens.

적인 함유량에 따른 LDPE 수지 film의 특성연구

Due to tightened environmental regulations on halogen type flame retardants, the portions of those based on phosphorous compounds that are non-halogen type is rising. When producing functional film, the physical and thermal properties become distinctly different depending on the amount of Red-phosphorus(RP) addition which causes flame resistance. The physical properties of resin fall in big scale when too much flame retardants are added, and it is hard to be applied to functional films such as shrink or anticorrosive film. The purpose of this research is to study the effects on mechanical, physical, and other properties of RP-LDPE films by changing the RP-MB contents. The LDPE film used for this study was produced through blow-type injection molding. The flame resistance was VTM-0, and the tear resistance showed inverse trends of MD and TD. Contraction percentage showed no relationship with the amount of RP content, but the anti-corrosive property showed 0.05 % better result than the national anti-corrosion shrink film reliability standard.

INTENSIDADE DE QUEIMA DE DIFERENTES RETARDANTES DE FOGO

RESUMOEsta pesquisa objetivou avaliar o efeito de diversos tipos de retardantes de fogo e dosagens na eficiência de combate aos incêndios florestais. O experimento foi realizado em mesa de combustão, em laboratório com quatro tipos de retardantes de fogo (WD 881, RFC-88, F-500 e HMIS 1-0-0 DPnb) em três concentrações (0,5%; 1%; e 1,5%), além de testemunha com água. A dosagem de calda da mistura de retardante com água utilizada foi de 0,5 L por metro quadrado de área. Para a análise, foi medido o tempo que o fogo levou para consumir a área com a aplicação do produto e a distância entre o início da parcela e o local onde o fogo se extinguiu. Durante a queima de cada parcela (tratamento/repetição), foram avaliadas as seguintes variáveis: umidade relativa, velocidade do vento, tempo gasto para o fogo queimar a parcela com e sem o produto e a distância que o fogo avançou na parcela com o produto. Os retardantes com maior eficiência foram o F-500, HMIS 1-0-0 DPnb e WD 881, que apresentaram diferença significativa pelo teste de Tukey a 5% de probabilidade, diferenciando-se da testemunha e do RFC-88. A concentração mais eficiente foi a de 1,5%, com as menores taxas de inflamabilidade em todos os casos.

Flame retardancies of novel organo-phosphorus flame retardants based on DOPO derivatives when applied to ABS

A series of novel organo-phosphorus flame retardants (FR) derived from 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide (DOPO) have been synthesized in order to investigate their flame retarding performances for acrylonitrile-butadiene-styrene copolymer (ABS). The success of synthesis was confirmed by 1H and 31P NMR. The flame retardancy performances evaluated by UL-94V test revealed that V-0 ratings are achieved when 27.5–30.0 wt% of FRs are added to the ABS/FR mixtures. The most dominating factors affecting the flame retardancy of phosphorus containing FR are the phosphorus (P) content in the mixture and the chemical structure of FR incorporated. It was found that 4.86–5.05 wt% P in the formulation is required to exhibit self-extinguishing ability when phosphinate or phophonate FRs are employed. On the other hand, no rating is obtained for phosphate type FR containing mixture even though higher amount of P, that is, 5.07 wt% is present in the mixture, indicating that oxidation state of the phosphorus element in FR is very important in governing the flame retardancy. The modes of actions of FRs in terms of gas versus condensed phase are also discussed. Thermogravimetric analysis (TGA) results showed that the FR containing compounds possess inferior thermal stability compared to neat ABS at the beginning of decomposition, suggesting that the thermal degradation of ABS is accelerated by the presence of FR at earlier stage of degradation and then hindered by the char formed at later stage of degradation.

Experimental Investigation of Program Voltage (20 V) Generation With Boost Converter for 3-D-Stacked NAND Flash SSD

This paper experimentally demonstrates program voltage (20 V) generation under emulated condition of a 3-D solid-state drive (3-D-SSD) which vertically integrates boost converter on an flame retardant type 4-interposer and Si-chips. The proposed program voltage generator is a boost converter using a coil on the interposer. A measured peak magnetic field power is approximately -49 dBm above the coil, which satisfies the international regulation. The magnetic field induces the eddy current in a conductor material. The eddy current degrades the boost converter performance due to the lowered effective inductance of the coil. The effects on the performance of the boost converter as a function of the distance from the coil to the conductor are experimentally investigated. A 3-D-SSD requires a >0.84-mm space between the coil and conductor to generate the program voltage. By inserting NAND flash memory chips between the coil and the conductor, a 3-D-SSD can be successfully realized without the output voltage degradation.