Thermal behavior and flame retardancy of flexible poly(vinyl chloride) treated with zinc hydroxystannate and zinc stannate

The flame‐retardant and smoke‐suppressant properties of inorganic tin compounds such as zinc hydroxystannate (ZHS) and zinc stannate (ZS) were studied in comparison with those of alumina trihydrate and magnesium hydroxide through the limiting oxygen index test and a smoke density test. The thermal degradation in air of flexible poly(vinyl chloride) (PVC) treated with the above compounds was studied by thermal analysis from ambient temperature to 800°C. The activation energy was calculated by using the Vyazovkin model‐free kinetic method and the Kissinger method. The results showed that tin compounds such as ZHS and ZS could be used as highly effective flame retardants for flexible PVC; these flame retardants enhanced the stability and the activation energy of the oxidation of the char. J. VINYL ADDIT. TECHNOL, 2008. © 2008 Society of Plastics Engineers     

Effect of co-additives on the flame/smoke suppression properties of zinc borates

Two zinc borates are useful partial replacements for the antimony oxide flame retardant normally used to flame retard flexible PVC products. The effect of using various co-additives with zinc borates on the flame retardancy and smoke formation of a model flexible PVC cable jacket was evaluated in an attempt to further improve the properties of the formulation. The use of ammonium octamolybdate with the borates yields products with improved properties. Highly flame retarded formulations that yield low levels of smoke can be prepared by using alumina trihydrate or magnesium compounds as replacements for the usual calcium carbonate filler. Replacement of part of the phthalate ester plasticizer with brominated ester, a phosphate ester, or a brominated phosphate ester also results in formulations with oxygen values as high as 39.5 which produce lower levels of smoke.     

Zinc hydroxystannate and zinc stannate as flame‐retardant agents for flexible poly(vinyl chloride)

The flame‐retardant and smoke‐suppressant properties of inorganic tin compounds such as zinc hydroxystannate (ZHS) and zinc stannate (ZS) were investigated in a comparison with alumina trihydrate, magnesium hydroxide, and Sb₂O₃ through the limiting oxygen index test and smoke density test. The flame‐retardant mechanisms were studied through the char yield test, SEM, quantitative analysis, thermogravimetry and differential thermal analysis. The thermal degradation in air of flexible PVC treated with the above compounds was studied by thermal analysis from ambient temperature to 800°C. The results showed that tin compounds such as ZHS and ZS could be used as a highly effective flame retardant for flexible PVC, and it appears that the tin compound may exert its action in both the condensed and vapor phases, but mainly in condensed phases as a Lewis acid. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 98: 1469–1475, 2005     

锡酸锌对软质聚氯乙烯的阻燃和抑烟作用

采用氧指数法、热重分析及烟密度测试法就锡酸锌对软质PVC的阻燃抑烟行为进行了研究。发现锡酸锌不仅是软质PVC的良好阻燃剂，更是一种性能优异的抑烟剂，添加15份时，最大烟密度只是空白试样的32．5％，氧指数为30．8，有可能代替三氧化二锑用于软质PVC的阻燃和抑烟。     

羟基锡酸锌的制备及其对PVC电缆材料的阻燃消烟作用

研究了在Sn4+和Zn2+共存的水溶液中,以氢氧化钠为沉淀剂合成的纳米羟基锡酸锌（ZHS）。采用X射线粉末衍射、傅里叶红外和环境扫描电镜表征证明合成的ZHS是边长为380nm左右的纳米立方体。采用"熔融共混法"制备PVC电缆材料,通过极限氧指数、烟密度、环境扫描电镜炭渣形貌表征比较了ZHS与三氧化二锑（AO）对PVC的阻燃消烟作用。通过真空裂解气相色谱－质谱联用分析了阻燃PVC电缆材料的裂解产物,并结合燃烧性能的测试结果,推断了ZHS对PVC电缆材料阻燃消烟作用的机理。结果表明,用量相同时,ZHS对PVC电缆材料的成炭作用总是优于AO。添加量小于10份时,AO对LOI和SDR的影响优于ZHS;但添加量大于15份后,增加ZHS的用量可以进一步提高氧指数和降低烟密度值。     

Zinc compounds as flame retardants and smoke suppressants for rigid PVC

Abstract

The effect of the concentration of zinc hydroxy-stannate and zinc borate on the fire performance of rigid PVC formulations has been investigated. Fire testing was carried out using cone calorimetry as well as the limiting oxygen index (LOI) test. In addition, further testing was done to check that incorporation of the fire retardant additives did not have any detrimental effects on other properties of the formulated PVC, such as heat stability, colour or impact strength. The results demonstrated that zinc hydroxy-stannate is an excellent fire retardant and smoke suppressant at additions levels of 3 parts per hundred parts of PVC. Zinc borate did not have the excellent fire retardant properties of zinc hydroxy-stannate, but was found to be an efficient and cost-effective smoke suppressant, although the presence of free zinc oxide in the sample affected the thermal stability of the formulation.     

Flame‐retardant and smoke‐suppressant properties of zinc borate and aluminum trihydrate‐filled rigid PVC

The effects of zinc borate (ZB), aluminum trihydrate (ATH), and their mixture on the flame‐retardant and smoke‐suppressant properties of poly(vinyl chloride) (PVC) as well as their mechanism for flame retardancy and smoke suppression were studied through the limiting oxygen index (LOI) test, smoke density test, TGA, GC–MS, and SEM. The results show that incorporation of a small amount of ZB, ATH, and their mixture can greatly increase the LOI of PVC and reduce the smoke density of PVC during combustion. The mixture of ZB with ATH has a good synergistic effect on the flame retardance and smoke suppression of PVC. TGA and GC–MS analyses results show that incorporation of a small amount of ZB, ATH, and their mixture greatly promotes the char formation of PVC and decreases the amount of hazardous gases such as benzene and toluene released in PVC during combustion. Their mechanism is also proposed. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 77: 3119–3127, 2000     

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     

Advances in the use of molybdenum compounds as smoke suppressants for PVC

Molybdenum-based compounds are effective smoke suppressants for rigid and flexible polyvinyl chloride formulations, both unfilled and filled with calcium carbonate and alumina trihydrate. These compounds, two of which are new compounds based on zinc molybdate with or without a phosphite synergist, are useful as is or extended onto core materials such as clay or talc. The addition of molybdenum-containing additives to flexible PVCs containing antimony trioxide usually raises the oxygen index and thus improves flame retardancy. Tests indicate that molybdenum acts as a flame and smoke suppressant in the solid phase.     

Zn2SnO4的制备及其对软质聚氯乙烯的阻燃研究

以结晶四氯化锡和硝酸锌为原料,通过2步煅烧法制备锡酸锌(Zn2SnO4)阻燃剂;通过极限氧指数、烟密度等级和残炭量研究了Zn2SnO4对软质聚氯乙烯（PVC）的阻燃和消烟性能的影响,同时对力学性能进行了研究。结果表明,Zn2SnO4的用量为15份时,对软质PVC的阻燃消烟效果明显,其极限氧指数可达36.0 %、烟密度等级为86.2 %、残炭率为29.7 %、拉伸强度为25.47 MPa、断裂伸长率为168 %;利用热重分析、差热分析和扫描电子显微镜等方法对阻燃PVC进一步进行表征,结果表明Zn2SnO4的加入促使软质PVC的起始分解温度降低,残炭量增加,燃烧后剩炭结构致密,阻燃效果明显。     

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。     

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.     

The influence of novel zinc hydroxystannate-coated fillers on the fire properties of flexible PVC

Zinc hydroxystannate (ZHS), at levels of 2-5 phr, and the hydrated fillers, magnesium hydroxide (MH) and alumina trihydrate (ATH), at levels of 20–50 phr, are effective flame retardants and smoke suppressants for flexible PVC. Novel ZHS-coated hydrated fillers are found to exhibit markedly improved fire-retardant properties, particularly with regard to increasing LOI values, reducing heat release rates and suppressing smoke generation, when compared with conventional uncoated forms. The ZHS coating appears to change the filler particle morphology and there is evidence that the coating is largely retained on the filler surface after melt processing into the PVC. The improved dispersion of the active tin compound in the polymer matrix leads to enhanced fire retardancy and this, in turn, allows significant reductions to be made in overall filler loading, with no loss in flame-retardant or smoke-suppressant performance. © 1997 John Wiley & Sons, Ltd.     

混合模板控制合成羟基锡酸锌包覆碳酸钙及其阻燃PVC研究

依据生物矿化原理,以十二烷基苯磺酸钠(SDBS)为模板,加入到乙二醇和水的混合溶液中制备了羟基锡酸锌包覆碳酸钙(ZHSCC-1),并将其和不添加SDBS/乙二醇模板制备的羟基锡酸锌包覆碳酸钙(ZHSCC-2)分别应用在聚氯乙烯（PVC）中进行对比研究,并通过X射线衍射、扫描电子显微镜、热重分析及差示扫描量热分析等方法对其性能进行了研究。结果表明,SDBS/乙二醇对碳酸钙形貌有调控作用,羟基锡酸锌对碳酸钙进行了较好的包覆,包覆产物粒径为5 μm的六方形薄片;在含量相同时,ZHSCC-1对PVC的阻燃消烟效果明显优于ZHSCC-2,且前者对PVC的拉伸强度、断裂伸长率、冲击强度的有益影响均优于后者。     

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.     

羟基硅油对无卤阻燃HDPE的改性

用氧氧化镁(MH)和水合硼酸锌(ZB)无卤阻燃高密度聚乙烯(HDPE)。测试了试样的拉伸强度、弹陛摸量、断裂伸长率、氧指数、维卡软化点。针对无卤阻燃体系韧性下降很大的缺点．采用羟基硅油进行增韧。结果表明：1000份MH和10份ZB可使体系氧指数达到28.0%，但同时韧性大幅下降，加入6份羟基硅油可在一定程度上改善材料的韧性     

Use of zinc borate as the third component of a traditional brominated flame retardant system in acrylonitrile butadiene styrene

Because zinc borate is an effective smoke suppressant and cheaper than antimony trioxide, the main aim of this study was to investigate usability of zinc borate as the third component of a traditional binary Br/Sb₂O₃ system in acrylonitrile butadiene styrene. Limiting oxygen index, UL‐94, and mass loss cone calorimeter studies indicated that almost all flame retardancy parameters were kept when certain percentages of antimony trioxide were replaced with zinc borate. Residue analysis revealed that the predominant flame retardancy mechanism of the traditional system was gas phase action, whereas zinc borate contributes especially in the condensed phase action by forming thicker and stronger char layer. Copyright © 2012 John Wiley & Sons, Ltd.     

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.     

FR characteristics of phosphate ester plasticizers with inorganic additives in PVC

Two common approachs to flame retard flexible PVC are phosphate ester plasticizers and antimony oxide. When used individually, each displays excellent flame suppressing characteristics. However, the combination of the two has been reported to show lower than expected flame resistance. Zinc borate plays a synergistic role with mixtures of phosphate ester plasticizers and antimony oxide, producing one of the most effective FR composite in this study. A review of this behavior in various PVC formulations is presented.     

半硬质聚氯乙烯塑料的阻燃性研究

本文研究了用于增塑半硬质聚氯乙烯材料的锑、硼、硅、钼、铝、锌等的化合物的复配阻燃体系。结果表明,该阻燃体系的协同作用是显著的,使用５～１０份复配阻燃剂的增塑半硬质聚氯乙烯材料的氧指数［０Ｉ］可提高８％～１２％,且发烟量较少