铁酸锌/包覆型氢氧化镁复配阻燃剂对PVC膜的阻燃抑烟性能分析

Analysis of flame retardant and smoke suppression performance of the PVC film with zinc ferrite/coated magnesium hydroxide

软质聚氯乙烯(PVC)膜在加工过程中添加了大量的增塑剂,导致其在空气中极易燃烧且在燃烧时会产生大量有毒有害烟雾。为了同时提升软质PVC膜的阻燃和抑烟性能,将单宁酸锌(TAZn)-羟基锡酸锌(ZHS)-氢氧化镁纳米片(MHS)多层包覆型杂化阻燃剂(TAZn-MHS@ZHS)与铁酸锌(ZnFe_(2)O_(4))复配获得复配阻燃剂,通过机械共混法将所得复配阻燃剂添加到PVC基体中,经热塑成型制备得到软质PVC复合膜。采用扫描电子显微镜(SEM)和拉曼光谱对PVC复合膜的形貌和残炭进行表征,通过垂直燃烧、烟密度、热失重等测试分析PVC复合膜阻燃抑烟性和热稳定性。结果表明:TAZn-MHS@ZHS与ZnFe_(2)O_(4)复配的阻燃剂与PVC基体具有良好的相容性,可以均匀分散于PVC基体中;当复配阻燃剂中TAZn-MHS@ZHS与ZnFe_(2)O_(4)复配比为3∶1,PVC复合膜的垂直燃烧等级达到V-0级,最大烟密度比纯PVC膜下降了67.5%;阻燃机理分析表明,TAZn-MHS@ZHS与ZnFe_(2)O_(4)复配比为3∶1的阻燃剂可以提高PVC膜燃烧后的炭层致密性及石墨化程度,有效隔绝氧气和可燃性气体的溢出,高效抑制了烟雾的释放,同时提高了PVC膜的阻燃和抑烟性能。该研究可为阻燃抑烟PVC复合材料的制备提供参考。

A large amount of plasticizers are added to the flexible polyvinyl chloride(PVC) film, which makes it easy to burn in the air and produces a large amount of toxic and harmful fumes. In order to simultaneously improve the flame retardant and smoke suppression properties of the flexible PVC film, zinc tannin(TAZn)-zinc hydroxystannate(ZHS)-magnesium hydroxide nanosheets(MHS) multilayer coated hybrid flame retardant(TAZn-MHS@ZHS) was compounded with zinc ferrite(ZnFe_(2)O_(4)), and the flexible PVC composite film was prepared by adding the compound flame retardant to the PVC matrix by solution blending. The morphology and carbon residue of the PVC film were characterized by SEM and Raman test while the flame retardant and smoke suppression properties and thermostability of the PVC composite film were analyzed by vertical combustion, smoke density and TGA, respectively. The results show that the compound flame retardant has good interfacial compatibility with PVC matrix and can be evenly distributed in it. When TAZn-MHS@ZHS is compounded with zinc ferrate(ZnFe_(2)O_(4)) spinel at a compounding ratio of 3∶1, the vertical combustion level of PVC film reaches V-0, and the smoke density decreases by 67.5 % compared with pure PVC films. The flame retardant mechanism analysis shows that the carbon layer of the PVC composite film after combustion is dense and has a high degree of graphitization, effectively isolating oxygen and combustible gases, inhibiting the release of smoke, and improving the flame retardant and smoke suppression performance of the PVC film. This study provides a reference for the preparation of flame-retardant and smoke-suppressed PVC composite materials.