Flame Retardancy Of Polymeric Materials Research Articles

A review on flame retardant technology in China. Part II: flame retardant polymeric nanocomposites and coatings

AbstractThe progress of flame retarded polymer nanocomposites and coatings in China over the past decades are described in this review. Emphasis on flammability performance of polymer nanocomposites containing nanofillers, mainly layered inorganic compounds, nanofibers and nanoparticles, combined with conventional flame retardant additives are addressed based on the open literature. Polymeric coatings with improved flame retardancy prepared using a wide variety of additives and UV‐curing technology are also introduced. Derived from this research, the combination of multiple methods and technologies including catalyst and nanotechnology, is predicted to have a high probability to enhance char formation and improve the flame retardancy of polymeric materials. Copyright © 2011 John Wiley & Sons, Ltd.

Simple Identification of Brominated Flame Retardants in Polymeric Materials by HPLC with Ultrasonic Extraction

A fast and simple method for the qualitative identification of brominated flame retardants (BFRs) in polymeric materials using ultrasonic-assisted extraction and liquid chromatography with PDA detection (HPLC-PDA) was developed. The identification of polybrominated diphenyl ethers (PBDEs), decabromobiphenyl (DeBB) was achieved within from 11 min to 19 min using ultraviolet detection in the scanning mode. On the other hand, tetrabromobisphenol A (TBBPA) and ethylenebis(pentabromophenyl) (EBPBP) were detected at 4.0 min and 26 min, respectively. The calibration curves from the peak areas of decabromodiphenyl ether (DeBDE), DeBB, TBBPA and EBPBP were linear with high correlation coefficients (R2 = 0.999). The detection limits of DeBDE, DeBDE, TBBPA and EBPBP were 0.1 μg/g for a 3 : 1 S/N ratio. The recoveries of DeBDE in standard plastic samples, which were certified by the GC-MS method (IEC62321 Annex A) ranged from 84% to 125%. The developed method can be applied to the screening of DeBDE in standard plastic samples.

Thermal properties and combustion characterization of nylon 6/MgAl-LDH nanocomposites via organic modification and melt intercalation

The nylon 6/MgAl layered double hydroxide (MgAl-LDH) nanocomposites have been prepared by melt intercalation of nylon 6 into the part organic dodecyl sulfate (DS) anion-modified MgAl(H-DS) interlayers. The structures and properties of MgAl(H-DS) and corresponding nanocomposites were characterized by ion chromotography, X-ray diffraction (XRD), transmission electron microscopy (TEM), differential scanning calorimetry (DSC), thermogravimetry analysis (TGA), and cone calorimeter test (CCT). The nanoscale dispersion of MgAl(H-DS) layers in the nylon 6 matrix has been verified by the disappearance of d 001 XRD diffraction peak of MgAl(H-DS) and the observation of TEM image. DSC tests evince that these exfoliated MgAl(H-DS) layers play the role of nucleating agents with strong heterogeneous nucleation effect on the crystallization of nylon 6 and increase its crystallization temperature over 12 °C with only 5 wt% MgAl(H-DS). TGA tests show that the effect of alkaline catalysis degradation from LDH on nylon 6 decreases the thermal stability of nylon 6/MgAl-LDH nanocomposites. The data from the cone calorimeter tests show that the HRR and MLR values of the sample with 5 wt% MgAl(H-DS) decrease considerably to 664 kW/m 2 and 0.161 g/m 2 s from 1064 kW/m 2 and 0.252 g/m 2 s of pure nylon 6, respectively. This kind of exfoliated nanocomposite is promising for the application of flame-retardant polymeric materials.

A Review of Recent Progress in Phosphorus-based Flame Retardants

Recent patent and technical works indicate a growing interest in halogen-free solutions with the predominance of the literature focusing on phosphorus-based flame retardants. Patents published on the flame retardancy of polycarbonate and its blends significantly exceed the number of patents on flame retardancy of any other polymer. Bridged aromatic diphenyl phosphates, especially resorcinol bis(diphenyl phosphate) and bisphenol A bis(diphenyl phosphate) have found broad application because of their good thermal stability, high efficiency, and low volatility. Another actively reported group of compounds are the metal salts of dialkylphosphonic acid as well as calcium hypophosphite, which have recently been found to be particularly effective in poly(butylene terephthalate) and polycarbonate. These products are synergistic with a number of phosphorus and nitrogen-containing compounds, such as melamine salts, which seem to be very efficient and commercially useful in nylons. Printed wiring boards comprise the largest market for flame-retardant polymeric materials. Recently, there has been a strong interest in halogen free solutions in East Asia and Europe. A recent halogen-free introduction is the 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, which can be reacted into epoxies. Another reactive product with some processing and property advantages is poly(m-phenylene methylphosphonate). Because of the banning of pentabromodiphenyl ether in Europe and voluntary withdrawal of this product from the market in the US, the polyurethane (PU) industry is searching for a more environmentally acceptable low-scorch alternative. Both halogenated and halogen-free solutions are being considered but the PU industry seems to have a preference for the halogen-free products, generally containing phosphorus.

Use of Boron Compounds as Flame Retardants for Polymeric Materials

Use of Boron Compounds as Flame Retardants for Polymeric Materials

Thermal degradation of 2,4,6-tri[(bromo)x anilino]-1,3,5-triazines

The need for more efficient and 'greener' flame retardants for polymeric materials is ever present and of increasing intensity as regulatory agencies continue to display concern about the environmental impact of traditional materials. Compounds capable of multiple modes of action would be particularly desirable. Compounds containing both bromine (for good gas-phase activity) and nitrogen (to promote solid-phase activity) should be good candidates for development as flame retardant agents. A series of 2,4,6-tri[(bromo)xanilino]-1,3,5-triazines have been synthesized and characterized spectroscopically. The degradation characteristics of these compounds have been examined using thermogravimetry. They undergo step-wise decomposition beginning at about 400°C.

CONFERENCE REPORT: Recent Advances in Flame Retardancy of Polymeric Materials

The fifteenth annual BCC Conference on flame retardancy (FR) of polymeric materials was held on June 7–9, 2004 in Stamford, Connecticut, USA. The conference was organized by Professor Menachem Lewin of the Polymer Research Institute of the Polytechnic University, Brooklyn, NY. It was sponsored by Business Communications Co. of Norwalk, CT. The program consisted of 35 presentations presented in five sessions, namely, general mechanisms of flame retardancy, halogen and non-halogen FR additives, nano-composites, customer focus/industrial products, and testing/standards/methods. There were also several posters and some exhibits. The symposium attracted about 100 participants from 15 countries. The day before the symposium a short course was presented on flame retardancy.

Aromatic polyimide foams: factors that lead to high fire performance

In this research, three different, closely related, polyimide foams (namely TEEK-H, TEEK-L, and TEEK-C) were comparatively studied including thermal, mechanical, surface, flammability, and degradation properties. TEEK-H series was the name given to ODPA/3,4′-ODA (4,4-oxydiphthalic anhydride/3,4-oxydianiline), TEEK-L series for BTDA/4,4′-ODA (3,3,4,4-benzophenenone-tetracarboxylic dianhydride/4,4-oxydianiline), and TEEK-CL for BTDA/4,4′-DDSO 2 (3,3,4,4-benzophenenone-tetracarboxylic dianhydride/4,4-diaminodiphenyl sulfone). With varying chemistries, densities, and surface areas of these foams, one has the ability to investigate the effects of subtle changes in density, surface area, and chemical structure on fire and thermal properties. Foams have much higher surface areas than solid polymers and are a greater challenge to fire retard [Weiser ES, Johnson TF, St. Clair TL, Echigo Y, Kaneshiro H, Grimsley B, Journal of High Performance Polymers 12 (2000) 1–12; Weiser ES, Baillif FF, Grimsley BW, Marchello JM, High temperature structural foam, Proceedings of the 43rd International SAMPE Symposium, May 1998, p. 730–44; Williams MK, et al., In: Nelson GL and Wilkie CA (Eds.), Fire and polymers: materials and solutions for hazard prevention, ACS Symposium Series 797, American Chemical Society/Oxford Press, Washington, D.C., 2001, p. 49–62; Williams MK, Nelson GL, Brenner JR, Weiser ES, St.Clair TL, Cell surface area and foam flammability, Proceedings of recent advances in flame retardancy of polymeric materials, 2001]. Detailed fire and thermal properties are discussed.

難燃剤ポリ臭素化ジフェニルエーテル（ＰＢＤＥｓ）による食品・母乳汚染

Polybrominated diphenyl ethers (PBDEs) have been used worldwide as additive flame retardants in polymeric materials. Commercial products consist predominantly of deca-, octa-, and pentabromodiphenyl ether mixtures. PBDEs are resistant to degradation in the natural environment and Penta-BDE in particular accumulates in the fatty tissues of fish, birds and mammals (including humans). Several toxic effects on the thyroid system or on neurodevelopment have been reported in experimental animals exposed to PBDEs. It is likely that human exposure is predominantly through the ingestion of contaminated food and/or mother's milk. The potential health effects of dietary exposure to PBDEs have now become a great concern because of the increasing PBDE levels in the biosphere. In this review, published information on the toxicology of PBDEs, levels in foodstuffs and human milk, and analytical methods has been compiled.

Synthesis and Characterization of PE‐g‐MA/MgAl‐LDH Exfoliation Nanocomposite via Solution Intercalation

AbstractAn organo‐modified MgAl‐layered double hydroxide (OMgAl‐LDH) was successfully exfoliated in the xylene solution of polyethylene‐grafted‐maleic anhydride (PE‐g‐MA) under re‐fluxing condition. A PE‐g‐MA/MgAl‐LDH exfoliation nanocomposite was formed after the precipitation of PE‐g‐MA from the dispersion system. The structure and thermal property of the PE‐g‐MA/MgAl‐LDH exfoliation nanocomposite were characterized by X‐ray diffraction (XRD), transmission electron microscopy (TEM), and thermogravimetry analysis (TGA). The disappearance of d001 XRD peak of OMgAl‐LDH at 20 = 3.2° suggests that the MgAl hydroxide sheets are exfoliated in the nanocomposite. The TEM image shows that the MgAl hydroxide sheets of less than 70 nm in length or width are exfoliated and dispersed disorderly in PE‐g‐MA matrix. TGA profiles indicate that the PE‐g‐MA/MgAl‐LDH nanocomposite with 5 wt% OMgAl‐LDH loading shows a faster charring process in temperature range from 210 to 390 °C and a greater thermal stability beyond 390 °C than PE‐g‐MA does. The decomposition temperature of the nanocomposite is 25 °C higher than that of PE‐g‐MA as measured at 50% weight loss. The PE‐g‐MA/MgAl‐LDH nanocomposite is promising for application of flame‐retardant polymeric materials.

Structural Characteristics and Thermal Properties of PE-g-MA/MgAl-LDH Exfoliation Nanocomposites Synthesized by Solution Intercalation

Exfoliated nanocomposites (PE-g-MA/MgAl-LDH) were synthesized by solution intercalation of polyethylene-grafted-maleic anhydride (PE-g-MA) into the galleries of organo-modified MgAl layered double hydroxide (OMgAl-LDH) under reflux in xylene. Their structural elucidation and thermal characterization were carried out by X-ray diffraction (XRD), Fourier transfer infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), selected area electron diffraction (SAED), thermogravimetric analysis (TGA), and differential thermal analysis (DTA). The molecular dispersion of OMgAl-LDH layers within the PE-g-MA matrix has been verified by the disappearance of d001 XRD diffraction peak of OMgAl-LDH and the observation of TEM image. The OMgAl-LDH layers of about 70-nm length or width show a disordered phase in PE-g-MA matrix. The SAED pattern demonstrates that the MgAl hydroxide sheets of about 0.48-nm thickness have a hexagonal crystal structure with a = 0.305 nm. TGA profiles of the PE-g-MA/MgAl-LDH nanocomposites show a faster charring process in temperature range from 210 to 360 °C and greater thermal stability above 370 °C than PE-g-MA. The decomposition temperature of the nanocomposites with 5 wt % OMgAl-LDH can be 60 °C higher than that of PE-g-MA when 50% weight loss was selected as a measuring point. Dynamic FTIR spectra reveal that this nanocomposite has a slower thermo-oxidative rate than PE-g-MA from 200 °C to 320 °C. This kind of exfoliation nanocomposite is promising for use in flame-retardant polymeric materials.

Polymer Combustion Processes. 3. Flame Retardants for Polymeric Materials

The nature and function of flame retardants for polymeric materials is discussed in this review of polymer combustion processes. The phenomenon of combustion is explained, together with the nature of the mechanism of retardation of combustion. Types of agents used to retard the combustion of polymers are discussed, and include metal hydroxides, organic halogen compounds, phosphorous compounds, and antimony trioxide synergists. Synergism is also described in a nitrogen/phosphorous and phosphorous/halogen system.

Polymer Combustion Processes. 3. Flame Retardants for Polymeric Materials

The nature and function of flame retardants for polymeric materials is discussed in this review of polymer combustion processes. The phenomenon of combustion is explained, together with the nature of the mechanism of retardation of combustion. Types of agents used to retard the combustion of polymers are discussed, and include metal hydroxides, organic halogen compounds, phosphorous compounds, and antimony trioxide synergists. Synergism is also described in a nitrogen/phosphorous and phosphorous/halogen system.

Synergistic and Catalytic Effects in Flame Retardancy of Polymeric Materials— An Overview

Synergistic and antagonistic effects of two or more additives are often encountered in flame retardancy of polymeric materials. Halo gen-antimony synergism is the best known. Evidence for bromine-ammonium, bromine-chlorine and bromine-phosphorus synergisms has been observed in some systems. Useful phosphorus-nitrogen synergism has frequently been ob served and has been studied in detail, with the result that various postulates can explain the effect. Combinations of phosphorus compounds are sometimes syner gistic and various combinations of phosphorus with intumescent char-forming agents are often highly efficacious as flame retardants.

Phosphonium Bromide Salts as Potential Flame Retardants for Polymeric Materials

Highly halogenated compounds. particularly multiply brominated aromatics, continue to be effective and widely uKd flame retardants for a vOricty of applications Phosphorus compounds, although somewhat more expensive than the brominated aromatics are effective at lower levels and function in both the solid and gas phase. The combination ofboth halogen and phosphorus in the m e compound can lead to a synergy of action and superior performance w a flame retardant.[1] The preparation of flame retardant compounds containing both halogen and phosphorous requires. first, the synthcsk of a hdogrmtcd compound that would dlow for a rusonable mount of phosphine to be incorpomtcd into the compound and. second, a compound that would also contain a rusonable percentage of hrlogen after phosphrus incorporation The halogenated compound rlccIed was 1,3,5-tri(bromomethyl)benzene. 1,3,5-Tri(bromomethy)benzene is a crystalline, tri-functional compound that is emnomid to produce and has a relatively high percentage of bromine (67.2%). Treatment of this cornpound with a variety of phosphines (which were generally available from reaction of the appropriate Grignard or orgrnolithium reagent with phosphorus trichloride) in dimcthylfomumide, usually at reflux, afforded the corresponding phosphonium bromides in excellent yields. [2] These salts are granular powders which should make excellent additives. The decomposition behavior of these materials as demonstrated by thermogravimctry suggest that they should be uxful in high temperature applications. Several of them have decompostion temperatures in excess of 300 C.

Identification of brominated flame retardants in polymeric materials by reversed-phase liquid chromatography with ultraviolet detection

A fast and simple method for the qualitative identification of technical flame retardants in polymeric materials is described. The LC separation was achieved on a reversed-phase C 18 column. The identification of a large variety of flame retardants in a single analytical LC run was achieved using a mixture of aqueous phosphate buffer and methanol with ultraviolet detection in the scanning mode. The method was used for the analysis of flame retardants in a number of polymeric waste materials from TV sets and personal computers, on the basis of a comparison with standards.

A comparative evaluation of a novel flame retardant, 3-(tetrabromopentadecyl)-2,4,6-tribromophenol (TBPTP) with decabromodiphenyloxide (DBDPO) for applications in LDPE- and EVA-based cable materials

Flame retardation of polymeric materials for cables is becoming a statutory requirement due to governmental regulations to protect life and property from damages caused by fire. This and other factors such as the ever-increasing cost of existing flame retardants (FRs) have given rise to the search for better FRs. In this article, the suitability of an FR, 3-(pentadecyltetrabromo)-2,4,6-tribromophenol (TBPTP) developed from cardanol was evaluated for use in cable insulating and jacketing materials based on low-density polyethylene (LDPE) and ethylene vinyl acetate (EVA). The processability, mechanical properties, compatibility and miscibility, thermal behavior, flammability behavior, smoke generation, acid emission, aging characteristics etc., of the blends of the FR with LDPE and EVA were studied in comparison to those of decabromodiphenyl oxide (DBDPO), which is a standard FR used by the cable industry. Although TBPTP is found to be less thermally stable than is DBDPO, it exhibited better flame retardancy and has comparable thermal stability when blended with LDPE and EVA. Both LDPE-TBPTP and EVA-TBPTP blends produced less smoke than did the corresponding blends of DBDPO. In the case of the EVA-TBPTP blend, the percentage emission of smoke was almost negligible, placing EVA-TBPTP under the low smoke grade. Formulations containing a synergistic agent, promoter, and filler with the corresponding FR and polymer polymer along with an antioxidant were extruded out into wire and tested for cable properties. At 20% loading, the LOI values of the blends were 34.6 and 32.5, respectively, for the TBPTP-EVA and DBDPO-EVA blends. Vertical burning tests carried out with EVA-TBPTP cable showed that it is self-extinguishable. The processability of the compositions containing TBPTP were better than those of DBDPO. The improved processability was found to be due to the plasticising effect of TBPTP. SEM pictures of the blend showed excellent distribution of TBPTP in the polymer, indicating good compatibility and miscibility. Comparatively, DBDPO did not exhibit uniform distribution. The mechanical properties of the blends were within specifications of standard cable materials except that the % elongation of the DBDPO-LDPE blend was far too low. Aging studies also gave better properties for the TBPTP system than for those of the DBDPO system. The overall results show that the properties of EVA-TBPTP cable fall within specifications for the FARLS grade, whereas the EVA-DBDPO cable did not. In the case of LDPE, both TBPTP and DBDPO did not satisfy specifications for the FRLS grade, but the data indicate that they can be used as FRs. The superiority in properties of the TBPTP system over DBDPO is explained in terms of the structure of TBPTP characterized by the distribution of the flame-retardant element, bromine, almost evenly between the aliphatic and aromatic moieties of the molecule, which can, in contrast to the fully aromatic DBDPO, provide halogen over a wide range of temperatures to the combustion zone of the decomposing polymer. Moreover, the presence of the aliphatic segment assures improved processability and compatibility.

高分子難燃化技術の最新動向

高分子難燃化技術の最新動向

Recent Advances in Flame Retardancy of Polymeric Materials (Materials, Applications, Industry Developments, Markets)

Abstract The Fifth Annual Conference on Flame Retardancy was held May 24–26, 1994, at the Ramada Plaza Hotel, Stamford, Connecticut, USA. The conference was organized by Business Communications Company, Inc., Norwalk, Connecticut (Company President, Mr. Louis Naturman; Conference Coordinator, Mrs. Sharon D. Faust). New materials (polymers, blends, composites), their applications, industry developments, and markets were considered. Specifically, the most important topics were: Introduction of new technological achievements and development in the field of flame retardancy (FR) Review of the current state of science and technology in FR Review of applications and markets for FR products Presentation of recent developments in local and global standardization and in testing technology Discussion of toxicity and environmental issues Provision of a unique opportunity for newcomers to FR research technology and marketing to become acquainted with the FR field in all its aspects Discussion of halogen-based and non-halogen-based flame retardant chemicals, syngergism, intumescence, FR mechanisms, modeling, flame parameters, inherently FR polymers, and polymer blends

Recent Advances in Flame Retardancy of Polymeric Materials: Materials, Applications, Industry Developments, Markets

Abstract The Fifth Annual Conference on Flame Retardancy was held on May 24–26 in Ramada Plaza Hotel, Stamford, Connecticut, USA. The Conference was organized by Business Communications Company, Inc., Norwalk, CT (President of company is Mr. Louis Naturman), conference coordinator—Mrs. Sharon D. Faust.