Tin dioxide coated calcium carbonate as flame retardant for semirigid poly(vinyl chloride)

The flame retardant and smoke suppressant properties of semirigid PVC treated with calcium carbonate (CaCO₃), tin oxide (SnO₂), the mixture of CaCO₃/SnO₂ and SnO₂‐coated CaCO₃ have been studied through the limiting oxygen index, char yield, and smoke density rating (SDR) methods. The thermal degradation in air of the treated semirigid PVC was studied by thermogravimetry (TG) and differential thermal analysis (DTA) from ambient temperature to 1073 K. The morphologies of the additives and the char formation were studied through SEM. The mechanical property was also studied. The results showed that the semirigid PVC treated with SnO₂‐coated CaCO₃ has a higher limiting oxygen index and char yield, lower SDR and MSDR, a more compact structure of char formation than the semirigid PVC without flame retardant and the semirigid PVC with the equivalent CaCO₃, or SnO₂, or the mixture of CaCO₃/SnO₂, a similar tensile property and greatly improved impact strength compared with that of the semirigid PVC without flame retardant. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 101: 731–738, 2006     

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。     

低熔点硫酸盐对软质PVC的阻燃与消烟性能研究

制得的硫酸盐混合物熔点低，在适当温度下熔融时，能有效地保护PVC降解过程中形成的剩磷，从而能提高剩碳率，提高阻燃与消烟性能。氧指数、烟密度、DTA、TG、SEM等证明了低熔点的硫酸盐是一种优良的填料性的、具有阻燃与消烟性的阻燃消烟剂，具有很好的消烟性，当添加量达40份时，烟密度能下降45％。研究表明其对力学性能的影响比其它填料小。     

SnO2和SiO2用于PVC的阻燃消烟及协同作用

研究了二氧化锡和二氧化硅对软PVC阻燃消烟性的影响。通过对极限氧指数、剩炭率、烟密度的测定和DTATG曲线的分析证明,添加8g二氧化锡/二氧化硅复合阻燃剂的PVC的氧指数和剩炭率比未添加的分别增高5.5个单位和4.1%,烟密度降低16.4%,降解活化能分别降低38kJ/mol和23.1kJ/mol,从而证明二氧化锡/二氧化硅复合阻燃剂对于PVC是一种很好的阻燃消烟剂,二氧化锡和二氧化硅有很好的协同作用。同时证明这种复合阻燃剂能代替三氧化二锑,使产品的成本进一步降低。     

Synergistic flame retardant effects of activated carbon and molybdenum oxide in poly(vinyl chloride)

The synergistic effects of activated carbon (AC) and molybdenum oxide (MoO₃) in improving the flame retardancy of poly(vinyl chloride) (PVC) were investigated. The effects of AC, MoO₃ and their mixture with a mass ratio of 1:1 on the flame retardancy and smoke suppression properties of PVC were studied using the limiting oxygen index and cone calorimeter tests. It was found that the flame retardancy of the relatively cheaper AC was slightly weaker than that of MoO₃. In addition, the incorporation of AC and MoO₃ greatly reduced the total heat release and improved smoke suppressant property of PVC composites. When the total content of AC and MoO₃ was 10 phr, PVC/AC/MoO₃ had the lowest peak heat release rate and peak smoke production rate values of 173.80 kW m^?2 and 0.1472 m² s^?1, which represented reductions of 47.3 and 59.9%, respectively, compared with those of PVC. Furthermore, thermogravimetric analysis and gel content tests were used to analyze the flame retardant mechanism of AC and MoO₃, with results showing that AC could promote early crosslinking in PVC. Char residue left after heating at 500 °C was analyzed using scanning electron microscopy and Raman spectroscopy, and the results showed that MoO₃ produced the most compact char, with the smallest and most organized carbonaceous microstructures. © 2017 Society of Chemical Industry     

系列羟基锡酸盐对半硬质PVC的阻燃消烟作用

研究了系列羟基锡酸盐阻燃剂对半硬质PVC的阻燃消烟作用。通过对样品燃烧后剩炭含量及扫描电镜(SEM)分析,探讨了锡酸盐体系阻燃抑烟的机理。结果表明:经阻燃处理的样品具有较高的极限氧指数(LOI)和剩炭率,较低的烟密度等级(SDR)和最大烟密度(MSD),与未处理的样品相比具有较好的阻燃和消烟性能。由于阻燃剂的添加量较少,对材料力学性能影响不大。     

Influence of Cu2+‐organic montmorillonites on thermal decomposition and smoke emission of poly(vinyl chloride) by cone calorimetric study

Cu²⁺‐Organic montmorillonites were prepared by modifying Na⁺ montmorillonite (Na⁺‐MMT) with silane coupling agents and cupric sulfate. PVC/organic montmorillonite composites were prepared by the melt intercalation method. Morphological structure of modified MMT and PVC/MMT was obtained by using XRD and SEM. The XRD results showed that silanes and Cu²⁺ were intercalated among interlayers and that modified MMT may have exfoliated dispersion in PVC. Effects of Cu²⁺‐organic montmorillonites on decomposition and smoke emission of poly(vinyl chloride) (PVC) in the flaming mode were investigated by using a cone calorimeter at an incident heat flux of 25 kW·m^?2. Cone experimental data demonstrated that the Cu²⁺‐organic montmorillonites prepared were new effective smoke suppressants. They clearly promoted an early HCl elimination, crosslinking reactions, and char residue formation, based upon the decomposition parameters of mass loss, mass loss rate, and time of initial decomposition (t_initial). Cu²⁺‐Organic montmorillonites decreased peak heat release rate, total heat release, peak smoke production rate, total smoke production, and smoke extinction area during the flaming process. The smoke‐reducing efficiency of Cu²⁺‐organic montmorillonites (Cu²⁺‐OMMTs) was the best. However, the content of cupric ion was only 0.6–0.8% in Cu²⁺‐OMMTs and 0.03–0.04% in PVC composites. They may make the smoke‐reducing efficiency reach 45–50%. This result further demonstrates that Cu²⁺ ion is a very effective smoke suppressant for PVC. J. VINYL ADDIT. TECHNOL., 13:31–39, 2007. © 2007 Society of Plastics Engineers.     

羟基锡酸锌包覆纳米氢氧化镁在PVC中的应用

通过均匀沉淀法制备了羟基锡酸锌包覆纳米氢氧化镁并将其应用到聚氯乙烯(PVC)中。利用XRD、TG、DTA对羟基锡酸锌包覆纳米氢氧化镁的性能进行了研究,并通过氧指数、烟密度研究了羟基锡酸锌包覆纳米氢氧化镁对PVC的阻燃和抑烟性能的影响,同时对其力学性能也进行了研究。结果表明:纳米氢氧化镁表面均匀地包覆了羟基锡酸锌;羟基锡酸锌包覆纳米氢氧化镁对PVC的阻燃和抑烟性能明显优于单独添加羟基锡酸锌、纳米氢氧化镁以及羟基锡酸锌包覆微米氢氧化镁和羟基锡酸锌与纳米氢氧化镁混和物时的阻燃、抑烟性能;纳米材料的加入对PVC的力学性能也产生了有利的影响。     

ZnO与Mg(OH)_2在软PVC中的协同阻燃消烟作用

用热分析的方法研究了ZnO和Mg(OH)2复合阻燃剂对软PVC的协同阻燃消烟作用,考察了经阻燃处理的软PVC从室温到800℃的热降解过程,用Kissinger方程给出了热降解反应的活化能。通过极限氧指数(LOI)、剩炭率、烟密度等级(SDR)和最大烟密度(MSD)的测定以及用电子扫描显微镜(SEM)对燃烧后所生成炭层的观察,探讨了协同体系阻燃抑烟的机理。结果表明:经阻燃处理的样品尤其是加入适量ZnO和Mg(OH)2复合阻燃剂的样品具有较高的极限氧指数(LOI)和剩炭率、较低的烟密度等级(SDR)和最大烟密度(MSD),与未处理的样品相比具有较好的阻燃和消烟性能。ZnO的加入可改变PVC的热降解过程,使起始降解温度降低,并且使反应的活化能增大,可能属于固相Lewis酸催化机理。     

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     

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.     

Metal hydroxystannates as flame retardants and smoke suppressants for semirigid poly(vinyl chloride)

Metal hydroxystannates were studied as flame retardants and smoke suppressants for semirigid poly(vinyl chloride) (PVC). The flame‐retardant and smoke‐suppression mechanisms were investigated by using limiting oxygen index (LOI), smoke density rating (SDR), the solid yield test (SY), scanning electron microscopy (SEM), thermogravimetry, differential thermogravimetry, and differential thermal analysis. Results showed that semirigid PVC treated with the flame retardants had a higher LOI, and solid yield, but a lower SDR and maximum smoke density, thereby indicating that the flame‐retardance and smoke‐suppression properties of the treated PVC were improved and that the hydroxystannate compounds could be used as highly effective flame retardants. The tin compounds may exert their action in both the condensed and vapor phases, but mainly in the condensed phase as Lewis acids. J. VINYL ADDIT. TECHNOL., 2008. © 2008 Society of Plastics Engineers.     

Mechanical properties,flame retardancy,and smoke suppression of lanthanum organic montmorillonite/poly(vinyl chloride) nanocomposites

A dimethyl dioctadecyl ammonium chloride modified organic montmorillonite (OMMT_‐I.44P)/poly(vinyl chloride) (PVC) nanocomposite and anionic‐surfactant‐modified lanthanum organic montmorillonite (La‐OMMT)/PVC nanocomposites (with three different anionic surfactants for the La‐OMMTs) were prepared via melt‐intercalation technology. The effects of the La‐OMMTs and OMMT_‐I.44P on the mechanical properties, flame retardancy, and smoke suppression of PVC were studied. X‐ray diffraction characterization showed that the La‐OMMTs were exfoliated in the PVC matrix. The mechanical properties of the nanocomposites were enhanced by the incorporation of the La‐OMMTs. Cone calorimetry and gas chromatography–mass spectrometry analyses indicated that the incorporation of the La‐OMMTs enhanced the flame retardancy and smoke suppression of the PVC nanocomposites. Scanning electron microscopy photos further showed that the residual char surfaces of La‐OMMT/PVC were all intact and, thus, provided better barriers to energy and smoke transport. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016 , 133, 43951.     

Thermal stability and flame retardance properties of acrylonitrile-butadiene-styrene/polyvinyl chloride/organophilic Fe-montmorillonite nanocomposites

In the article, acrylonitrile-butadiene-styrene/polyvinyl chloride/organophilic Fe-montmorillonite (ABS/PVC/Fe-OMT) nanocomposites were prepared by melt intercalation method. In order to determine if the presence of iron ion in the structure of organophilic montmorillonite (OMT) lattice can affect thermal, flame retardance and smoke suppressant properties in the ABS/PVC blends. ABS/PVC/organophilic natural montmorillonite (Na-OMT) nanocomposites were prepared as the comparable sample. Fe-MMT and Na-MMT were treated by cetyl trimethylammonium bromide (CTAB). The information on morphologies and structures of ABS/PVC/OMT nanocomposites was obtained using X-ray diffraction (XRD) and transmission electron microscopy (TEM). The thermal properties of the nanocomposites were characterized by thermogravimetric analysis, and flame retardant properties were obtained via limiting oxygen index (LOI), UL-94 vertical burning test and smoke density. The nanocomposites, based on Fe-OMT, exhibited better flame retardance, better smoke suppressant properties, and lower degradation degree than those of pure ABS/PVC blends and the ABS/PVC/Na-OMT nanocomposites.     

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     

磷钼酸铵的制备及性能

对新型阻燃抑烟剂——磷钼酸铵的制备和性能进行了研究;利用XRD、IR、DSC和TG对所制备的磷钼酸铵进行了表征,为磷钼酸铵的应用提供了理论基础。将磷钼酸铵加入PVC中,并与常用的阻燃抑烟剂Sb2O3、MoO3、Al(OH)3等进行对比,通过对阻燃材料氧指数和烟密度的测试表明,磷钼酸铵具有良好的阻燃抑烟性能;力学性能测试表明,磷钼酸铵与高分子材料具有良好相容性,是一种性能出众的新型阻燃抑烟剂,具有广阔的应用前景。     

An investigation of inorganic tin flame retardants which suppress smoke and carbon monoxide emission from burning brominated polyester resins

In view of the current demand for novel, non-toxic, flame- and smoke- suppressant systems for synthetic polymers, certain inorganic tin compounds have been evaluated as fire retardants in a series of commercial brominated polyester resin formulations. The results obtained clearly show that zinc hydroxystannate (ZnSn(OH)₆) and zinc stannate (ZnSnO₃) impart beneficial properties to the polyesters in terms of flame retardancy and smoke/carbon monoxide suppression, and the improvements in performance are, in general, superior to those exhibited by tin (IV ) oxide or antimony (III ) oxide. The surface area and degree of dispersion of the fire-retardant additive has been shown to have a marked effect on its efficiency and, in this connection, colloidal tin (IV ) oxide is found to exhibit significantly improved flame-retardant properties compared to powdered SnO₂. Simultaneous thermal analyses (TG/DTG/DTA) and related mechanistic experiments have shown that tin additives markedly increase the amount of char formed during combustion, whereas Sb₂O₃, a vapour-phase flame retardant, has little effect on char formation. The zinc stannates also appear to exhibit a significant vapour-phase activity, and this may account for their flame-retardant superiority to SnO₂ itself.     

Flame‐retardant properties of magnesium hydroxystannate and strontium hydroxystannate coated calcium carbonate on soft poly(vinyl chloride)

The flame‐retardant and smoke‐suppressant properties of soft poly(vinyl chloride) (PVC) treated with zinc hydroxystannate (ZHS), calcium carbonate (CaCO₃), magnesium hydroxystannate [MgSn(OH)₆], strontium hydroxystannate [SrSn(OH)₆], ZHS–MgSn(OH)₆, ZHS–SrSn(OH)₆, MgSn(OH)₆‐coated CaCO₃, SrSn(OH)₆‐coated CaCO₃, ZHS–MgSn(OH)₆‐coated CaCO₃, and ZHS–SrSn(OH)₆‐coated CaCO₃ were studied with the limited oxygen index, char yield, and smoke density rating methods; the mechanical properties were also studied. The results showed that, with the equivalent addition of the corresponding hydroxystannate, the soft PVC treated with hydroxystannate‐coated CaCO₃ had a higher limited oxygen index than the corresponding hydroxystannate, and the soft PVC treated with the agents containing magnesium had a higher limited oxygen index than the soft PVC treated with the agents containing strontium, except for ZHS–MgSn(OH)₆‐coated CaCO₃. The improvement in the char formation of the hydroxystannate‐coated CaCO₃ was better than that of the corresponding hydroxystannate in most cases, and the aforementioned agents reduced the smoke density rating, decreased the tensile strength, and increased the elongation and impact strength basically. Thermal analysis showed that the additives promoted the evolution of hydrogen chloride, early crosslinking, and rapid charring through the strong catalyzing effect of Lewis acids. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

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     

磷钼酸钙阻燃抑烟剂的制备和性能研究

采用MoO3、磷酸、氢氧化钙制得磷钼酸钙，利用XRD、IR、DSC和TG对其进行了表征；将磷钼酸钙作为阻燃抑烟剂加入到PVC中，并与常用的阻燃抑烟剂Sb2O3、MoO3、Al(OH)3等对照。结果表明，加入了磷钼酸钙的PVC材料的氧指数达到27．1％，有焰燃烧的烟密度为297，无焰燃烧的烟密度为351，具有良好的阻燃抑烟性能，且对PVC的力学性能影响较小。