Contribution of nanoclays to the performance of traditional flame retardants in ABS

The purpose of this study was to investigate contribution of nanoclays to the flame retardancy performance of a traditional brominated flame retardant compound with various combinations of antimony trioxide and zinc borate. The matrix polymer acrylonitrile butadiene styrene (ABS) was compounded by melt mixing in a laboratory size twin‐screw extruder. X‐ray diffraction analysis and transmission electron microscopy revealed that nanoclay silicate layers were mainly intercalated with certain level of exfoliation in ABS matrix. Flammability analysis investigated by mass loss calorimeter, limiting oxygen index, and UL‐94 tests indicated that use of nanoclays improved all flame retardancy parameters significantly. For instance, the increase in the limiting oxygen index was up to 32% O₂, while the suppression in peak heat release rate value was as much as 82%, of course in each specimen the highest rating of V‐0 in UL‐94 test was obtained. Thermogravimetric and other residue analyses pointed out that these contributions were especially due to the condensed phase flame retardancy mechanism of nanoclay which contributes stronger and carbonaceous char formation acting as a barrier to heat and flammable gases and retarding volatilization via tortuous pathway. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers     

机场行李分拣输送机用橡胶鳞板的研制

以丁腈橡胶为主体材料研制高耐磨、阻燃的机场行李分拣输送机用橡胶鳞板。研究了促进剂CZ/TT并用的活化次磺酰胺类硫化体系和聚氯乙烯、氯化石蜡、三氧化二锑、硼酸锌并用阻燃体系对胶料物理性能和阻燃性能的影响。结果表明,当促进剂CZ/TT并用比为0.7/0.35时,胶料的物理性能较好;聚氯乙烯、氯化石蜡、三氧化二锑、硼酸锌并用比为30/25/12/9时,胶料的物理性能和阻燃性能最好。     

微胶囊红磷在软质PVC电缆料的应用研究

研究了微胶囊红磷不同包覆、用量、粒径及与其他阻燃剂的协效作用等因素对软质聚氯乙烯（PVC）电缆料的阻燃性能、力学性能及抑烟性能的影响。蜜胺树脂／硼酸锌双层囊材包覆微胶囊红磷在PVC中的阻燃性最好；6份的微胶囊红磷添加量即可使材料的阻燃性能达UL94 V-0级。随着微胶囊红磷颗粒粒径减小，材料氧指数增大，阻燃性提高，拉伸强度和断裂伸长率有所提高。二元体系中，微胶囊红磷／氢氧化铝、微胶囊红磷／氢氧化镁和微胶囊红磷／硼酸锌复配具有良好的阻燃协效作用。微胶囊红磷／三氧化钼、微胶囊红磷／二茂铁二元复合体系对PVC有明显的抑烟作用，最大烟密度（有焰）分别下降为62．9和144．9。微胶囊红磷／硼酸锌二元复合体系有良好的抑烟协效作用。微胶囊红磷／硼酸锌／十溴联苯醚和微胶囊红磷／氢氧化铝／氢氧化镁三元复合体系有很好的阻燃和抑烟协效作用。     

Enhanced flame retardancy and thermal stability of zinc borate and magnesium carbonate as a promising alternative for Sb2O3 toward polyvinyl chloride

Inorganic zinc compounds such as zinc carbonate (ZC) and zinc borate (ZB) are considered as promising alternatives for harmful antimony trioxide in the future, but may result in poor thermal stability for flexible polyvinyl chloride (PVC). To enhance the flame retardancy and static thermal stability of flexible PVC, zinc compounds with environmentally friendly magnesium carbonate (MC) were introduced into PVC matrix. Findings reveal that the simultaneous use of 5 phr ZB and 5 phr MC for flexible PVC exhibits satisfactory properties containing pronounced flame retardancy with a limiting oxygen index of 30.2% and a UL-94 V-0 rating without dripping, enhanced static thermal stability with high color stability by discoloration tests, reduced smoke emission, and decent mechanical properties, which are advantageous over the standalone use of ZC, ZB, and MC. The enhancement mainly due to that the incorporation of ZB can accelerate the dehydrochlorination and promote the charring of flexible PVC in the early stage of flame burning, and MC can perform the long-term static thermal stability due to the HCl absorption capacity.     

Experimental investigation of related properties of asphalt binders containing various flame retardants

The improved flame retardancy of asphalt binders containing various kinds of flame retardants including antimony trioxide, decabromodiphenyl ether (EBPED), aluminium trihydroxide (ATH) and zinc borate (ZB) under different additive concentrations was investigated by limited oxygen index (LOI) and differential scanning calorimetry (DSC) test. To assess the effects of the type and concentration of the flame retardants on rheological properties of asphalt binders, the softening point, penetration, ductility, storage stability and viscosity were tested. The thin film oven test (TFOT) was used to investigate the effect of short-term oxidation on flame-resistant asphalt binders. Experimental results indicated that all of selected flame retardants had a relatively small effect of rheological properties of the asphalt binders, but a great effect on flame retardancy. Asphalt binder with LOI of 25.9 was obtained by adding 6 wt% mixed flame retardants of EBPED: antimony trioxide: ZB=3:1:1 by mass. Asphalt binder was transformed from inflammable materials into flame retardant materials. Therefore, the asphalt binder with both good flame retardancy and rheological properties is a novel road functional material to meet two respects' demands as flame retardant materials and road materials at the same time.     

阻燃抑烟剂对软聚氯乙烯材料燃烧性能的影响

针对氢氧化镁、硼酸锌、三氧化二锑等常用的阻燃抑烟剂对在软聚氯乙烯燃烧时的热释放速率和一氧化碳释放量进行了研究 ,发现氢氧化镁和硼酸锌虽然可以降低材料的热释放性能和发烟量 ,但是会大大增加烟气中一氧化碳的释放量 ;而三氧化二锑会增加材料的发烟量 ,但却能大大降低烟气中的一氧化碳的释放量     

阻燃剂与芳纶浆粕对三元乙丙橡胶性能影响的研究

以十溴二苯乙烷(DBDPE)、三氧化二锑和硼酸锌等作阻燃剂,以超细芳纶浆粕短纤维作耐烧蚀材料,通过共混方式制备了EPDM阻燃材料和耐烧蚀材料。研究了EPDM阻燃复合材料的阻燃性能、物理机械性能和燃烧炭化层微观结构形态。结果表明,三氧化二锑/硼酸锌/DBDPE用量分别为8份/20份/20份时,阻燃复合材料极限氧指数可达26.9%,垂直燃烧级别达到UL94—V0级;加入60份DBDPE时,极限氧指数达到36.3%;DBDPE/三氧化二锑/硼酸锌用量分别在60份/15份/20份以下时,对EPDM硫化胶拉伸性能无不利影响;三氧化二锑能明显提高DBDPE的阻燃性能;加入硼酸锌后氧指数略有提高,且明显改善抑烟效果和成炭效果;加入芳纶浆粕短纤维,对阻燃性能影响不大,但能明显改善炭化层致密性。     

锡酸锌包覆碳酸钙对聚氯乙烯的阻燃消烟作用

用氧指数、剩炭率、烟密度等方法测试了锡酸锌包覆碳酸钙对PVC的阻燃作用,同时采用热分析、扫描电镜的方法研究了锡酸锌包覆碳酸钙的阻燃机理。实验表明在锡酸锌含量相同的情况下,锡酸锌包覆碳酸钙对PVC的阻燃和消烟性能优于锡酸锌;在添加量为10份时,锡酸锌包覆碳酸钙阻燃PVC样品和三氧化二锑阻燃PVC样品具有相同的氧指数,但当添加量为20份时,前者的氧指数比后者的高3%,前者的烟密度等级比后者低约10%。     

微胶囊红磷阻燃剂在软质聚氨酯泡沫塑料中的应用研究

研究了微胶囊红磷不同包覆、用量、粒度及与其它阻燃剂的协效作用等因素对软质聚氨酯泡沫塑料的阻燃性能、力学性能及抑烟性能的影响。三聚氰胺～甲醛树脂／硼酸锌双层囊材包覆微胶囊红磷在聚氨酯中的阻燃性最好；3份的微胶囊红磷添加量即可使材料的阻燃性能达UL94V-0级，氧指数(LOI)从17．7％上升到28．8％；在适当的添加量范围内对材料的力学性能影响很小；粒径的逐渐减小，材料氧指数值逐渐增大，阻燃性提高，拉伸强度和伸长率随粒径增大而略有降低；二元体系中，微胶囊红磷／硼酸锌与微胶囊红磷／十溴联苯醚复配具有很好的阻燃协效作用，协效指数分别为2．4和1．4，三元体系中，微胶囊红磷／韧弭酸锌什溴联苯醚体系有很好的阻燃协效作用，协效指数为1．6，LOI为34．9％。     

复合型改性无机阻燃剂在PVC中的应用

文章介绍了阻燃剂的阻燃作用及其分类,并综述了各种常用阻燃剂的阻燃机理。研究了稀土改性氢氧化镁(Mg(OH)2)、氢氧化铝(Al(OH)3)、三氧化二锑(Sb2O3)、硼酸锌(2ZnO·3B2O3·3.5H2O(ZB))、改性红磷为主的复合阻燃体系对糊状PVC阻燃性能的影响。通过氧指数测定仪对样品的氧指数测定,根据单因素分析寻找出复合无机阻燃剂的最佳配方。     

Improvement of thermal stability and flame retardancy of polypolypropylene composite modified by ZnO and MoO3 nanowires

Herein, zinc oxide (ZnO) and molybdenum trioxide (MoO₃) nanowires were prepared via the hydrothermal method. Then as-prepared ZnO and MoO₃ nanowires were fabricated to form ZnO/MoO₃ compound nanostructure. ZnO/MoO₃ compounds were incorporated into polypropylene (PP) with various loadings by melt blending. The D-Optimal mixing design in Design-Expert software was employed to study the effects of ZnO/MoO₃ compound content on flame retardancy and mechanical properties of nanocomposites. Information on performance of thermal stability and flame retardancy of PP/ZnO/MoO₃ nanocomposites was obtained through thermogravimetric analysis, cone calorimeter tests, and limiting oxygen index (LOI). The results reflected that the synthesized ZnO/MoO₃ compound possessed high thermal stability and flame retardancy. The addition of 15 wt % ZnO nanowires and 13 wt % MoO₃ nanowires increased LOI from 18.2 to 23.0%. Meanwhile, the tensile strength of the PP/ZnO/MoO₃ nanocomposite decreased by 13.8% and the elongation at break of the PP nanocomposite increased by 20.4% compared with pure PP. Response surface analysis results also indicated that the loading of ZnO/MoO₃ compound had an influence on the mechanical properties and flame retardancy of PP. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 48312.     

The flame retardant effect of aluminum phosphinate in combination with zinc borate,borophosphate, and nanoclay in polyamide‐6

The effect of zinc borate (ZnB), borophosphate (BPO₄), and organoclay were studied to improve the flame retardancy of polyamide‐6 composites containing organic phosphinates. The flame retardancy of polyamide‐6 composites was investigated using limiting oxygen index (LOI), Underwriters Laboratories (UL‐94) standard, thermogravimetric analysis, Fourier transform infrared spectroscopy, and mass loss calorimeter. The addition of 15 wt% aluminum phosphinate (AlPi) increased the LOI value from 22.5 to 29.5, and V0 rating was obtained from UL‐94 test. The addition of organoclay, ZnB, and borophosphate does not change the predominant gas phase mechanism of AlPi during LOI and UL‐94 tests. The addition of organoclay increased the condensed phase mechanism of AlPi physically by the protective effect of layered silicate, whereas the addition of ZnB increased the condensed phase mechanism of AlPi chemically by the formation of boron aluminum phosphate species deducted from mass loss calorimeter studies. Copyright © 2012 John Wiley & Sons, Ltd.     

Hydrated and anhydrous zinc borate fillers for tuning the flame retardancy of epoxy nanocomposites

In this study, hydrous (Zn₃B₆O₁₂·3.5H₂O) and anhydrous (ZnB₂O₄) forms of zinc borates were synthesized at 150 and 175°C under moderate pressure conditions (85 and 150 psi, respectively). Synthesized zinc borates were controllably incorporated (1, 5, and 10 wt%) in epoxy resin to prepare their nanocomposites. The flame-retardant and mechanical properties of these nanocomposites were determined and compared in terms of their flame spread testing, smoke density, limiting oxygen index, and flexural strength. Superior properties in terms of flame retardancy were observed for epoxy composites containing hydrous filler as compared to anhydrous zinc borates. Although flexural strength was observed to be decreased with increasing filler concentration, the marked drop is lower for composites with hydrous zinc borate as compared to the anhydrous one. The variations in flame-retardant and mechanical properties of composites with both types of fillers are related to their morphological (field emission scanning electron microscopy), X-ray diffraction (XRD) analysis, Fourier Transform Infrared (FTIR), differential scanning calorimetry, and thermogravimetry analysis and explained with condensed phase mechanism.     

含锌阻燃剂对NER/OMMT-TPP体系阻燃聚丙烯的影响

将硼酸锌和氧化锌加入到酚醛环氧树酯/有机蒙脱土纳米复合材料(NER/OMMT)与磷酸三苯酯(TPP)阻燃聚丙烯(PP)体系,考察了硼酸锌和氧化锌用量对PP阻燃、抑烟性能和力学性能的影响.在NER/OMMT与TPP总用量仅为10wt%的情况下加入4wt%的硼酸锌后,制得了氧指数高达31.5%的阻燃聚丙烯,并且烟雾产生总量比加入前下降了46.6%,在降低了材料的毒害性的同时很好地提高了其综合性能.     

Recent studies on the use of zinc borate as a flame retardant and smoke suppressant in PVC

By the Oxygen Index test, zinc borate alone is an effective flame retardant in rigid PVC. In flexible PVC formulations containing 50 phr of dioctyl phthalate as the plasticizer, zinc borate in combination with antimony oxide displays a synergistic effect at a total loading of more than 10 phr (1-to-1 ratio). In the presence of 30 phr of alumina trihydrate, this synergism increases significantly at a total loading as low as 5 phr. Zinc borate also shows strong synergism with alumina trihydrate. Zinc borate acts as a smoke suppressant in plasticized PVC. With alumina trihydrate, a strong smoke-reducing synergism is created. Zinc borate in a flexible PVC formulation markedly increases the amount of char formed, whereas the addition of antimony oxide, a vapor phase flame retardant, has little effect on char formation. Zinc borate is a good afterglow suppressant. Volatilized zinc derived from the zinc borate probably contributes to flame retardancy but not to smoke suppression. Zinc compounds can alter the pyrolysis chemistry by catalyzing dehydrohalogenation and promoting crosslinking, resulting in increased char formation and a decrease in both smoke production and flaming combustion.     

软质PVC阻燃抑烟的研究

介绍了各类阻燃剂(如氢氧化铝、氢氧化镁、锑系、磷系、硼系、钼系)的性能及阻燃机理,并对软质PVC材料的阻燃抑烟性能进行了实验。结果表明：经偶联剂处理过的阻燃剂,由于增强了其与基体的界面结合力。从而使其力学性能得到提高;三氧化钼的用量对聚合物的阻燃效果影响不明显,而随着硼酸锌和三氧化二锑用量的增加,其阻燃效果越来越好。     

微胶囊红磷阻燃剂在低密度聚乙烯材料中的应用研究

研究了微胶囊红磷不同包覆、用量、粒径及与其它阻燃剂的协效作用等因素对低密度聚乙烯(LDPE)材料的阻燃性、力学性能及抑烟性能的影响。蜜胺树脂囊材包覆与蜜胺树脂／硼酸锌双层囊材包覆微胶囊红磷在聚乙烯(PE)中的阻燃性最好；8phr的微胶囊红磷添加量即可使材料的阻燃性能达UL 94V-0级，极限氧指数(LOI)从17．4％上升到22．5％；在添加量范围内对材料的力学性能影响很小；二元体系中，微胶囊红磷／氢氧化铝，微胶囊红磷／氢氧化镁与微胶囊红磷／硼酸锌复配具有良好的阻燃协效作用，协效指数分别为1．6、1．4和2．3，微胶囊红磷／硼酸锌二元复合体系有良好的抑烟协效作用，三元体系中，微胶囊红磷／硼酸锌／十溴联苯醚、微胶囊红磷／氢氧化铝／氢氧化镁和微胶囊红磷／硼酸锌／三聚氰胺体系有很好的阻燃协效作用，协效指数分别为2．6、2．1与2．0。     

Effect of boron‐containing materials on the flammability and thermal degradation of polyamide 6 composites containing melamine

Three different boron‐containing substances—zinc borate (ZnB), borophosphate (BPO₄), and a boron‐ and silicon‐containing oligomer (BSi)—were used to improve the flame retardancy of melamine in a polyamide 6 (PA‐6) matrix. The combustion and thermal degradation characteristics of PA‐6 composites were investigated with the limiting oxygen index (LOI), the UL‐94 standard, thermogravimetric analysis (TGA)/Fourier transform infrared (FTIR) spectroscopy, and differential scanning calorimetry (DSC). A slight increase was seen in the LOI values of a sample containing BSi (1 wt %). BPO₄ at high loadings showed a V0 rating (indicating the best flame retardancy) and slightly lower LOI values in comparison with samples with only melamine. For ZnB and BSi, glassy film and char formation decreased the dripping rate and sublimation of melamine, and this led to low LOIs. According to the TGA–FTIR results, the addition of boron compounds did not change the decomposition product distribution of melamine and PA‐6. The addition of boron compounds affected the flame retardancy by physical means. The TGA data showed that boron compounds and melamine reduced the decomposition temperature of PA‐6. According to the DSC data, the inclusion of boron compounds increased the onset temperature of sublimation of melamine and also affected the flame retardancy negatively. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

The effects of inorganic borates on the burning of PVC

The flammability of flexible poly(vinyl chloride) sheet containing barium, calcium and zinc borates, alone and in combination with antimony oxide, was measured by BS2782-508C and ASTM D2863. A statistical comparison of these tests was made. Barium and calcium borates, with or without antimony oxide, had little or no effect on flame retardancy, but zinc had a synergistic effect with antimony oxide. The value of these inorganic borates in reducing smoke is compared using the Stanton Redcroft F.T.B. Unit, an attachment of the manufacturer's Critical Oxygen Index (C.O.I.) test. This test consists of passing the smoke from the C.O.I, test directly into a chamber where the maximum smoke density is measured using a light source and photocell assembly. Formulations containing zinc borate and antimony oxide gave the least smoke. The advantages of zinc borate in flame retardant poly(vinyl chloride) were found to be offset by inferior mechanical and electrical properties and heat stability, unless small amounts of epoxidised oil were added. The degree of hydration of the zinc borate was not critical.     

低密度聚乙烯阻燃薄膜性能研究

以十溴二苯醚、三氧化二锑为阻燃剂,对包装用低密度聚乙烯薄膜制品的阻燃性能和力学性能进行了研究,并用氧指数测试仪和万能试验机评价其阻燃性能和力学性能。实验结果表明:在DBD-PO/Sb2O3/LDPE体系中,两种阻燃剂之间明显存在协同阻燃效应,极限氧指数大幅度提高;其力学性能也达到了相应的使用标准。