New developments in fire retardant non‐halogen aromatic phosphates

Akzo Nobel Chemicals has recently introduced on the market an aromatic oligomeric phosphate (BDP) based on Bisphenol A. This product shows higher thermal and hydrolytic stability than other aryl phosphates. It provides similar or better fire retardant performance than an oligomeric phosphate (RDP) based on resorcinol. Fire retardant formulations with BDP based on polycarbonate/ABS plastic (PC/ABS) blend, polyphenylene oxide/high impact polystyrene (PPO/HIPS) blend, and HIPS alone show similar or better physical properties than those obtained with RDP. Upon thermal decomposition of the fire retarded polymers containing BDP, phosphorus tends to accumulate in the solid residue, a result which indicates that the primary fire retardant action of BDP is likely to occur in the condensed phase.     

Flame retardancy mechanisms of triphenyl phosphate,resorcinol bis(diphenyl phosphate) and bisphenol A bis(diphenyl phosphate) in polycarbonate/acrylonitrile–butadiene–styrene blends

The flame retardancy mechanisms of three aryl phosphates, triphenyl phosphate (TPP), resorcinol bis(diphenyl phosphate) (RDP) and bisphenol A bis(diphenyl phosphate) (BDP), in a polycarbonate/acrylonitrile–butadiene–styrene (PC/ABS) blend are investigated and compared. Further, the influence of polytetrafluorethylene (PTFE) on viscosity and thermal decomposition is discussed in the systems PC/ABS and PC/ABS + BDP. Mechanisms are proposed based on the results of various methods. Thermogravimetric analysis, Fourier transform infrared spectroscopy and kinetics are used to study the pyrolysis. The fire behaviour is studied by means of cone calorimeter measurements at different heat fluxes and the flammability is specified by limiting oxygen index (LOI) and UL 94. Rheology measurements are used to illuminate the changed dripping behaviour due to PTFE. TPP shows only a gas phase action. RDP shows mainly a gas phase action and some condensed phase action. BDP shows a crucial condensed phase action in addition to a gas phase action. TPP and RDP are somewhat superior in terms of flammability (LOI), whereas BDP shows superior performance in forced flaming combustion (cone calorimeter). Synergistic effects between PTFE and BDP are found. Copyright © 2007 Society of Chemical Industry     

不同芳基磷酸酯与膨胀型阻燃剂复配阻燃PP的研究

采用间苯二酚双(二苯基)磷酸酯(RDP)、双酚A双(二苯基)磷酸酯(BDP)、磷酸三甲苯酯(TCP)和异丙苯基磷酸酯(IPP)作为阻燃协效剂与膨胀型阻燃剂(IFR)复配阻燃聚丙烯(PP)。研究了芳基磷酸酯的种类对PP/IFR复合材料阻燃性能、热稳定性能和力学性能的影响,并通过热重分析(TGA)、扫描电镜(SEM)等对材料进行了表征。结果表明:芳基磷酸酯对PP/IFR复合材料具有一定的协同阻燃作用。当芳基磷酸酯用量为5.0%时,PP/IFR/TCP、PP/IFR/IPP、PP/IFR/RDP和PP/IFR/BDP复合材料的氧指数(OI)由PP/IFR的28.5%分别提高到29.5%、30.0%、30.5%和29.5%,垂直燃烧级别由UL 94V-1级提升至UL 94V-0级;同时,RDP和BDP可提高PP/IFR复合材料的热稳定性能,500℃时的残余率分别高达15.4%和12.9%。此外,RDP和BDP的加入有利于IFR粒子的分散,从而改善了材料的力学性能。     

Fire‐retardant action of resorcinol bis(diphenyl phosphate) in PC–ABS blend. II. Reactions in the condensed phase

The thermal decomposition of polycarbonate (PC), PC containing resorcinol bis(diphenyl phosphate) (RDP), and PC—acrylonitrile–butadiene–styrene (PC–ABS) blend containing RDP was studied by thermogravimetry. Volatile and solid products of thermal decomposition were collected at different steps of thermal decomposition and characterized either by gas chromatography–mass spectrometry or infrared and chemical analysis. It was found that phosphorus accumulates in the condensed phase. Upon combustion of the fire‐retardant mixture PC–ABS + RDP, accumulation of phosphorus is observed in the charred layer, at the surface of the burning specimens. It is suggested that PC undergoes a Fries‐type rearrangement upon thermal decomposition, and RDP reacts with the formed phenolic groups through a trans‐esterification mechanism. Kinetic analysis of the thermal decomposition of PC containing RDP supports the proposed mechanism. © 1999 John Wiley & Sons, Inc. J Appl Polym Sci 71: 1863–1872, 1999     

磷酸酯齐聚物阻燃剂的合成及应用

以三氯氧磷、间苯二酚、双酚A和苯酚等为原料合成了间苯二酚型磷酸酯齐聚物和双酚A型磷酸酯齐聚物，其结构经红外光谱、高效液相色谱和热重分析表征。研究了催化剂种类和用量对反应的影响以及反应物配比和溶剂对产物性能的影响，结果表明，MgCl2的催化效果最好，最佳用量为1％，三氯氧磷与双酚类化合物的最佳摩尔比为1：4．5-5．0。磷酸酯齐聚物阻燃剂在树脂阻燃方面的应用实验表明，其对聚碳酸酯、聚苯醚、聚苯醚倩抗冲聚苯乙烯和聚对苯二甲酸丁二醇酯的阻燃可达到UL94 V-0级。     

芳基磷酸酯/膨胀型阻燃剂协同阻燃PP的制备及性能研究

以间苯二酚双(二苯基)磷酸酯(RDP)为阻燃协效剂,与三聚氰胺焦磷酸盐(MPP)和季戊四醇(PER)组成的膨胀型阻燃剂(IFR)复配,制备了具有良好阻燃性能的无卤阻燃聚丙烯(PP)。研究了RDP的用量对PP/IFR体系阻燃性能和力学性能的影响,并通过热重分析(TGA)和动态热机械分析(DMA)等手段对阻燃材料进行了表征。结果表明:RDP与IFR具有明显的协同阻燃作用。当RDP质量分数为5.0%时,阻燃PP的氧指数(LOI)从28.5%提高至30.5%,UL-94由V-1级提升至V-0级;此外,体系的缺口冲击强度也有较大幅度提高。     

The flame‐retardance polylactide nanocomposites with nano attapulgite coated by resorcinol bis(diphenyl phosphate)

The nano attapulgite (ATP) coated by flame‐retardant resorcinol bis(diphenyl phosphate) (RDP) was prepared, and the modification effects were analyzed by scanning electron microscopy plus energy dispersive spectrometer, Fourier‐transform infrared spectra, the contact angles, and thermal gravimetry analysis. The results showed that RDP was adsorbed and formed a uniform layer on the surface of nano ATP with a content of about 25 wt%. The prepared polylactide (PLA) nanocomposites with the RDP‐coated nano ATP showed good mechanical properties, and the tensile strength of the nanocomposites containing 30 wt% of the RDP‐coated nano ATP reached 76.9 MPa in comparison with 66.2 MPa of pure PLA. The limiting oxygen index of the prepared PLA composites containing 30 wt% of the RDP‐coated nano ATP was about 24.5% and V‐0 rating was attained compared with 20.5% and with no rating of pure PLA. After the burning of the flame‐retardant PLA composites, a compact and coherent charred layer was formed; the flame‐retardance mechanism is discussed in detail. J. VINYL ADDIT. TECHNOL., 22:506–513, 2016. © 2015 Society of Plastics Engineers     

磷酸酯阻燃PC/ABS合金的研究及应用

研究了磷酸三苯酯（TPP）、间苯二酚双（二苯基磷酸酯）（RDP）、缩聚型固体磷酸酯（PX）和增容增韧剂对聚碳酸酯（PC）/丙烯腈-丁二烯-苯乙烯共聚物（ABS）合金阻燃性能的影响。结果表明,TPP、RDP、PX均可显著提高PC/ABS合金的阻燃性能,增容增韧剂可以改善体系的力学性能;当PC/ABS为7/3时,分别加入11 %、14 %和12 %（质量分数,下同）的3种阻燃剂,并配以适量的增容增韧剂和其他助剂,可以制得等级为UL94 V-0级的PC/ABS合金。     

磷酸酯类阻燃剂在PC／ABS合金中的应用

文章研究了磷酸酯类阻燃剂RDP、BDP以及它们与TPP的协同作用对PC／ABS合金的阻燃性能、热失重行为以及力学性能的影响。结果表明,PC／ABS合金的LOI随着阻燃和的增加而增加,当阻燃剂RDP和BDP添加量均为15％时,LOI达到最大值,分别为363％和35．3％,且均达FV-0级。通过热重分析表明,阻燃PC／ABS比纯PC／ABS合金的分解速率小得多。研究还表明,阻燃剂的协同作用使PC／ABS合金的阻燃性能优于添加单一阻燃剂的PC／ABS合金的阻燃性能。     

Influence of phosphorous-based flame retardants on the mechanical and thermal properties of recycled PC/ABS copolymer blends

The effects of three commercial aryl phosphate flame retardants (FRs; bisphenol A bis(diphenyl diphosphate) [BDP], triphenyl phosphate (TPP), and a proprietary oligomeric phosphate ester (OPE)) and a compatibilizer (methacrylate-butadiene-styrene copolymer [MBS]) on the thermal and mechanical properties of FR-recycled PC/acrylonitrile-butadiene-styrene copolymer (r-PC/r-ABS) blends are investigated. The addition of FRs to r-PC/r-ABS blends increases the storage, tensile, and flexural moduli, indicating a reinforcing effect. However, at elevated temperatures, FRs reduce the glass transition temperature and act as plasticizers. The thermal stability of r-PC/r-ABS/FR blends at 10% mass loss increases in the following order: r-PC/r-ABS/TPP < r-PC/r-ABS/BDP < r-PC/r-ABS/OPE < r-PC/r-ABS/OPE/MBS. Kinetics of thermal decomposition of the FR r-PC/r-ABS blends is studied calculating the thermal decomposition activation energies by the Flynn–Wall–Ozawa method. Scanning electron microscopy shows that r-PC/r-ABS/OPE blend is only partly miscible, while homogeneous structure is formed in the r-PC/r-ABS/OPE/MBS blend, which is supported by its good mechanical and thermal properties. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48377.     

Synergistic barrier flame‐retardant effect of aluminium poly‐hexamethylenephosphinate and bisphenol‐A bis(diphenyl phosphate) in epoxy resin

Two flame retardants, aluminium poly‐hexamethylenephosphinate (APHP) and bisphenol‐A bis(diphenyl phosphate) (BDP), were incorporated into diglycidyl ether of bisphenol A (DGEBA) thermoset with 4,4′‐diaminodiphenyl sulfone (DDS) as curing agent, and then the synergistic flame‐retardant behaviors of the cured thermosets were investigated. Compared with thermosets containing 10 wt% APHP and 10 wt% BDP alone, the sample with 3.3 wt% APHP and 6.7 wt% BDP (3.3%APHP/6.7%BDP/EP; EP is DGEBA/DDS) possessed a better flame‐retardant effect since its limited oxygen index reached 35.0% and in the UL94 test it passed the V‐0 rating. The cone calorimeter test revealed that the 3.3%APHP/6.7%BDP/EP sample generated less gaseous fragments and more smoke particles instead of fuels and verified that APHP and BDP exhibited an outstanding synergistic effect on the barrier effect. Macroscopic digital photos and micrographs from scanning electron microscopy further disclose that BDP facilitated the formation of a flexible film covering holes in the residue. The flexible film was combined with aluminium phosphate particles which were produced by decomposed APHP, thereby forming a char layer with increased barrier effect. The synergistic barrier effect from APHP and BDP imposed a better flame‐retardant performance for epoxy thermosets. © 2017 Society of Chemical Industry     

Halogen‐free flame‐retardant rigid polyurethane foams: Effect of alumina trihydrate and triphenylphosphate on the properties of polyurethane foams

Rigid polyurethane foam (PUF) filled with mixture of alumina trihydrate (ATH) and triphenyl phosphate (TPP) as fire retardant additive was prepared with water as a blowing agent. In this study, the ATH content was varied from 10 to 100 parts per hundred polyol by weight (php), and TPP was used at a higher loading of ATH (75 and 100 php) in a ratio of 1 : 5 to enhance the processing during PUF preparation. The effects of ATH on properties such as density, compressive strength, morphological, thermal conductivity, thermal stability, flame‐retardant (FR) behavior, and smoke characteristics were studied. The density and compressive strength of the ATH‐filled PUF decreased initially and then increased with further increase in ATH content. There was no significant change in the thermal stability with increasing ATH loading. We determined the FR properties of these foam samples by measuring the limiting oxygen index (LOI), smoke density, rate of burning, and char yield. The addition of ATH with TPP to PUF significantly decreased the flame‐spread rate and increased LOI. The addition of TPP resulted in easy processing and also improved FR characteristics of the foam. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Thermal stabilities and flame retardancies of phloroglucinol‐based organo phosphates when applied to polycarbonate

A series of organo phosphorus flame retardants (FRs) based on aromatic phosphate and cyclic phosphate were synthesized in an attempt to develop an efficient FR for polycarbonate. Their successful synthesis was confirmed by FT‐IR and ¹ H and ³¹P NMR. Their thermal stability and flame retarding efficiency as a single‐component additive were investigated and compared with the commercial FR, resorcinol bis(diphenyl phosphate). The thermogravimetric analysis results revealed that the aromatic phosphate synthesized in this study, phloroglucinol diphenyl phosphate (PDP), shows a higher thermal degradation temperature and better flame retardancy even though it has a lower P content than cyclic phosphate‐based FRs. The flame retarding efficiency was evaluated by the UL‐94 test method. The V‐0 rating was achieved at a PDP loading of 2 wt% in polycarbonate in the presence of an anti‐dripping agent (1 wt%), which is better than that of resorcinol bis(diphenyl phosphate) and cyclic phosphate‐based FRs. The high thermal stability and P–OH generation tendency is responsible for the better flame‐retarding performance of PDP. The degradation path of PDP is also discussed. Copyright © 2012 John Wiley & Sons, Ltd.     

Synergistic effect of organophosphate functionalized montmorillonite on properties and water resistance of intumescent flame‐retarded SEBS

Polystyrene‐b‐(ethylene‐co‐butylene)‐b‐styrene (SEBS) is a widely used thermoplastic elastomer. However, it suffers from poor flame retardancy. Proper combination of organic‐modified montmorillonite and intumescent flame retardant (IFR) works but is not stable due to easy absorption of moisture. In this study, a novel and stable halogen‐free flame‐retardant system is demonstrated by encapsulating a hydrophobic organophosphate, ie, bisphenol A bis (diphenyl phosphate) (BDP) into a stable micelle and then “attaching” the BDP micelles to the montmorillonite (called: side‐intercalation). The resulted BDP modified montmorillonite (BMMT) has a large inter‐platelet spacing and demonstrated synergistic effect with IFR on flame retardancy, tensile property, and water resistance for the composite with SEBS. In addition to more homogeneous dispersion of IFR and BMMT, a longer‐lasting interfacial interaction between IFR and SEBS matrix with addition of small amount of BMMT also plays the role. The results suggest that BMMT can serve as an effective additive for formulating novel halogen‐free flame retardants for the SEBS to meet increasingly stricter environmental requirements.     

双酚A双(磷酸二苯酯)/聚磷酸铵膨胀阻燃剂对环氧树脂阻燃性能研究

通过氧指数、垂直燃烧、热失重、锥形量热和电镜扫描等研究了由双酚 A 双(磷酸二苯酯)(BDP)与聚磷酸铵(APP)组成的膨胀型阻燃剂对环氧树脂的阻燃性能和阻燃机理。结果表明,BDP/APP 膨胀型阻燃剂对环氧树脂有较好的阻燃性能,使环氧树脂氧指数达到29.9%,垂直燃烧通过 UL94 V-0级,500℃残炭量达到34 8%,平均热释放速率下降70.7%,热释放速率峰值下降67.3%,有效燃烧热平均值下降24.1%。扫描电镜分析表明,经膨胀阻燃剂阻燃的环氧树脂燃烧后能够形成连续、致密、封闭、坚硬的焦化炭层。     

Resorcinol bis(diphenyl phosphate), a non-halogen flame-retardant additive

This paper is a review of Resorcinol bis(diphenyl phosphate) (RDP), a non-halogen aromatic oligomeric phosphate flame-retardant and flow modifier. Its high thermal stability and low volatility, compared with the triaryl phosphates, make it ideal for use in applications where high processing temperatures are requuired. Thermogravimetric data showing the effects of RDP on modified PPO and polycarbonate/ABS blends are presented. Current and potential end uses in thermoplastic resins and polyurethanes are discussed.     

NE/OMMT纳米复合物与RDP复配阻燃ABS的制备与性能

采用酚醛环氧树脂/有机蒙脱土(NE/OMMT)纳米复合物与间苯二酚双(二苯磷酸酯)(RDP)复配作为阻燃剂,制备了阻燃ABS;研究了OMMT用量对ABS阻燃性能及力学性能的影响;并通过TGA、XRD、TEM对材料进行了表征。结果表明:NE/OMMT纳米复合物与RDP对ABS具有很好的协同阻燃作用,当OMMT、NE和RDP用量分别为0.5%、6.0%和9.0%时,阻燃ABS氧指数高达39.0%,且力学性能优良;OMMT的添加提高了阻燃ABS的热稳定性;OMMT经NE插层后,层间距明显增大,与ABS熔融共混后可产生部分剥离。     

Effects of phosphate and polysiloxane on flame retardancy and impact toughening behavior of poly(2,6‐dimethyl‐1,4‐phenylene oxide)

Poly(2,6‐dimethyl‐1,4‐phenylene oxide) (PPO)‐based compounds containing resorcinol bis(diphenyl phosphate) (RDP) and poly(dimethyl‐diphenyl siloxane) (PDMDPS) were prepared through melt extrusion, and their flammability characteristics and mechanical properties were evaluated. The incorporation of RDP enhanced the flame retardancy of PPO compounds, but hardly made them obtain the UL 94 V‐0 rating unless RDP and PDMDPS were combined. Studies on the residual chars after vertical burning test suggested that the excellent flame retardancy be correlated with the retention from the combination effects of silica and phosphate in the char, whose cross‐linked silica enhanced the formation of a compact char to retard combustion. Thermogravimetric analysis indicated that the presence of PDMDPS and RDP improved the char yielding as well as the decomposition temperature of PPO compounds. Moreover, the Izod impact strength was improved significantly in the presence of RDP and PDMDPS, and this toughening effect was attributed to the deformation and multiple cracks induced by PDMDPS, which enhances the impact energy absorption of the matrix. This work provides a very effective flame retarding formulation for PPO compounds with improved impact toughness. POLYM. ENG. SCI., 2012. © 2011 Society of Plastics Engineers     

无卤阻燃PC/ABS合金性能及应用

通过非等温热失重方法对无卤阻燃剂双酚A双磷酸二苯酯(BDP)和Sb2O3及其复配体系,以及采用该类阻燃剂的聚碳酸酯(PC)/(丙烯腈/丁二烯/笨乙烯)共聚物(ABS)合金的热分解行为进行了研究;同时,对采用该类阻燃剂的PC/ABS合金的力学性能、阻燃性能进行了研究,并通过扫描电镜对加入BDP的PC/ABS合金的微观结构进行了研究.结果表明,BDP/Sb2O3为7/3、质量分数为10%时,合金的综合性能优良,氧指数达到29.5%,缺口冲击强度达到84.23 kJ/m2>;BDP对PC/ABS合金具有一定的增容效果.合金可用于汽车行业、电子电器等行业.     

How Phosphorous Flame Retardant Additives Affect Benzoxazine-Based Monomer and Polymer Properties

The phosphorous-based flame retardant additives poly(m-phenylene methylphosphonate) (PMP) and resorcinol bis(diphenyl phosphate) (RDP) are reacted with bisphenol F and aniline–based benzoxazine (BF-a). DSC, rheological analysis, FT-IR, and soxhlet extraction reveal the covalent incorporation of both FR additives—initiating phenols in PMP structure as well as free phenols generated via transesterification reaction in the case of RDP. In contrast to PMP, RDP elongates the processing window but decreases the thermo–mechanical properties. Both additives increase the resistance in reactions against small flames with solely a phosphorous loading of 0.3 wt%, resulting in a V-0 rating and an improvement in the OI value by up to 2% for RDP and 4% for PMP. Both FRs reduce the heat release rate but increase the smoke production and the smoke toxicity in the case of RDP.