纳米水滑石/氧化锌抑烟阻燃复合体系对软质PVC性能的影响

The Effect of Nano-Hydrotalcite Composites on Smoke Suppression and Flame Retardant of Flexible PVC

研究了纳米水滑石（LDHs）／纳米氧化锌（ZnO）复合抑烟阻燃体系对软质聚氯乙烯材料抑烟阻燃、力学性能和热稳定性的影响。实验结果表明：当LDHs为3份、ZnO为2份时，纳米LDHs／ZnO复合抑烟阻燃体系组分之间具有良好的协同效应。阻燃抑烟PVC材料在燃烧过程中发生膨胀，膨胀厚度为2—4cm。当纳米LDHs／ZnO组分含量为5份时，材料的烟密度等级（SDR）由95．8降低到70．1，明显低于GB／T8627．1999国家标准要求，极限氧指数（LOI）由25．5％提高到32．5％，力学性能变化不明显。热重分析表明热失重率明显低于对照样品，600℃残重率由11．8％提高到22、6％。通过透射电镜观察纳米LDHs／ZnO复合组分为5份时，能够达到纳米级分散。

The effect of nano-LDHs/ZnO on flame retardant and smoke suppression of flexible PVC was investigated by means of smoke density rank （SDR） , limiting oxygen index （LOI） , TEM, TG analysis and mechanical test. The results indicated that the addition of nano-LDHs/ZnO had a significant effect on smoke suppression and flame retardance when the ratio of LDHs/ZnO was 3： 2. The expension was formed during the burning process. When the total mass content of flame retardant and smoke suppression was 5phr, the SDR decreased from 95.8 to 70. 1 ,the LOI exhibited a maximum value 32.5% compared to 25.5% ,the mechanical properties changed slightly. TG analysis showed that the mass loss of flexible PVC composite was obviously lower than which of the sample without nano-LDHs/ZnO, and the residue was increased from 11.8% to 22.6% at 600℃. According to TEM, the size of LDHs/ZnO particles was less than 100nm when their total mass content was 5 phr.