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.     

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。     

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。     

Low‐melting sulfate glasses as additives to semirigid PVC and their flame retardant and smoke suppressant properties

The role of low‐melting sulfate glasses (LMSG) as additives on the flame retardant and smoke suppressant properties of semirigid poly(vinyl chloride) (PVC), as well as the mechanism for flame retardancy and smoke suppression, were studied through the Limiting Oxygen Index (LOI) test. Smoke Density Rating (SDR) test, DTA‐TG, and SEM. The results show that the LMSG have good smoke suppressant properties. When the PVC compound contains 40 parts of LMSG, the SDR value will be reduced by about 45%. The Cu²⁺, Zn²⁺, Mn²⁺, and Ni²⁺ sulfates, as well as MoO₃, cause PVC to crosslink and form char, and the melt can protect not only the char formed during combustion and thermal degradation, but also undecomposed polymer. That is the main mechanism for flame retardation and smoke suppression when the additives melt. The mechanical properties of the PVC compounds containing different levels of LMSG were also studied.     

Flame retardancy and mechanical properties of pet‐based composites containing phosphorus and boron‐based additives

Flame retardancy of poly(ethylene terephthalate), PET, was improved using different flame retardant additives such as triphenylphosphate, triphenylphosphine oxide, zinc borate, and boron phosphate (BP). Composites were prepared using a twin screw extruder and subsequently injection molded for characterization purposes. The flame retardancy of the composites was determined by the limiting oxygen index (LOI) test. Smoke emission during fire was also evaluated in terms of percent light transmittance. Thermal stability and tensile properties of PET‐based composites were compared with PET through TGA and tensile test, respectively. The LOI of the flame retardant composites increased from 21% of neat PET, up to 36% with the addition of 5% BP and 5% triphenyl phosphate to the matrix. Regarding the smoke density analysis, BP was determined as an effective smoke suppressant for PET. Enhanced tensile properties were obtained for the flame retardant PET‐based composites with respect to PET. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42016.     

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     

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。     

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。     

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     

超细硼酸锌阻燃剂的制备及其性能研究

以硼砂和氯化锌为原料,研究了原料浓度、搅拌速度、乳化剂种类和用量等因素对硼酸锌粒径和粒径分布的影响。通过优化实验,制备了超细硼酸锌,数均平均粒径73nm,比表面积31.5m2/g,90%的粒子在纳米尺度范围。XRD衍射图与采用化学分析测定结果证明产物为低水硼酸锌(2ZnO.3B2O3.3.5H2O),电镜分析表明其晶体形貌为不规则的球形。将超细硼酸锌应用于聚氯乙烯,当硼酸锌用量为树脂质量的10%~30%,成炭率比未阻燃的聚氯乙烯大幅增加。表明超细硼酸锌在提高聚氯乙烯阻燃性的同时有很好的抑烟效果。     

Zinc‐based compounds as smoke suppressant agents for an aerospace epoxy matrix

Smoke is considered to be the main hazard of fires involving epoxy resins but its production depends on many variables, principally the chemical character and the burning rate of the polymer plus the availability of oxygen. The work reported aimed to study the smoke suppressant effect and flammability performance of zinc‐based compounds (FR system) in epoxy matrix composites used in the aerospace and aeronautical industry. The flammability performance of neat and FR‐loaded systems was screened using microcombustion calorimetry, while smoke generation, in terms of carbon monoxide (CO) and carbon dioxide (CO₂) production, was analysed under dynamic conditions using cone calorimetry. Final results indicate that the dispersion of zinc borate and zinc hydroxystannate (ZHS) into epoxy matrices leads to a significant variation in flame retardant properties reducing both total heat release by about 25 and 30%, respectively, and heat release capacity by about 30 and 50%, respectively. The system containing ZHS shows an enhancement in all smoke suppressant properties; both tin compounds (zinc stannate (ZS) and ZHS) give a reduction of CO₂/CO ratio from 41 to 25 for ZS and from 41 to 36 for ZHS compared to neat matrix. Copyright © 2010 Society of Chemical Industry     

仿生合成羟基锡酸锌包覆碳酸钙及其对PVC的阻燃研究

采用仿生合成的方法,以十二烷基苯磺酸钠(SDBS)为模板,在水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模板制备的羟基锡酸锌包覆碳酸钙(ZHSCC-2)分别应用在PVC 中进行对比研究.结果表明:在ZHSCC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...     

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。     

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.     

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。     

电缆用高阻燃耐热软质PVC的制备及性能研究

以软质PVC为基体,选用氢氧化铝-氢氧化镁(ATH/MDH)为复配阻燃剂、硼酸锌(ZB)为阻燃协效剂及钙锌材料为复合热稳定剂(Ca-Zn),通过共混法对PVC进行改性,制备PVC/ATH/MDH、PVC/ATH/MDH/ZB及PVC/ATH/MDH/ZB/Ca-Zn等软质PVC复合电缆料。分析3种电缆料的阻燃性能、拉伸性能及热稳定性。结果表明:相较纯软质PVC,PVC/ATH/MDH与PVC/ATH/MDH/ZB的阻燃性能提高,拉伸性能显著下降,且热稳定性改善不明显。而PVC/ATH/MDH/ZB/Ca-Zn的阻燃性能显著提升,与纯软质PVC相比,其极限氧指数(LOI)增加34.90%,烟密度等级下降29.50%,复合材料的炭层更连续且致密;PVC/ATH/MDH/ZB/Ca-Zn的拉伸强度和断裂伸长率分别提高1.78%和2.48%。Ca-Zn的添加提高软质PVC的残炭率,热稳定性增强。PVC/ATH/MDH/ZB/Ca-Zn的综合性能最佳。     

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     

Fire and flame retardants for PVC

The flammability performance of PVC plays a significant role in its selection for many applications. Its relatively high chlorine content (56.8%) makes it more resistant to ignition and burning than most organic polymers. In the case of flexible PVC, the plasticizers that contribute flexibility in most instances detract from its resistance to fire. To meet specifications such as oxygen index, heat release, smoke evolution, or extent of burning in cable tests, flame‐retardant (FR) and smoke‐suppressant (SS) additives are often incorporated. Synergistic combinations of FR and SS additives help PVC formulations meet many stringent FR specifications cost effectively.     

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.