单层和双层包覆ZnSnO_3微胶囊对PVC膜阻燃及抑烟性能影响

采用极限氧指数(LOI)值、垂直水平燃烧测试、烟密度测试(SDR)、SEM、TG分析,研究了单层ZnSnO_3@Mg(OH)_2微胶囊和双层ZnSnO_3@Mg(OH)_2@三聚氰胺甲醛树脂(MF)微胶囊对聚氯乙烯(PVC)膜的阻燃及抑烟性能的影响。结果表明,ZnSnO_3@Mg(OH)_2和ZnSnO_3@Mg(OH)_2@MF微胶囊能有效提高PVC膜阻燃、抑烟、抗熔滴、自熄性能;且随着单层或双层微胶囊含量的增加,ZnSnO_3@Mg(OH)_2/PVC和ZnSnO_3@Mg(OH)_2@MF/PVC膜的极限氧指数增加,但其烟密度和自熄时间降低。TG结果表明,随着微胶囊含量增加,ZnSnO_3@Mg(OH)_2/PVC和ZnSnO_3@Mg(OH)_2@MF/PVC膜的初始降解温度向低温偏移,且其残炭量增加。ZnSnO_3@Mg(OH)_2/PVC和ZnSnO_3@Mg(OH)_2@MF/PVC膜的残炭SEM表明,添加ZnSnO_3@Mg(OH)_2和ZnSnO_3@Mg(OH)_2@MF微胶囊能有效地促进材料燃烧时产生致密碳层,不仅可以抑制氧气和热量进入PVC膜内部,而且可以抑制可燃性气体向PVC膜外逸出。SEM和拉伸强度结果显示,双层微胶囊可有效改善无机粒子在PVC基体中的分散性和相容性。

Effect of single-and double-layer encapsulated ZnSnO3 on flame retardancy and smoke suppression properties of poly(vinyl chloride) membrane composites

The influence of single layer ZnSnO3@Mg(OH)2 microcapsule and double layer ZnSnO3@Mg(OH)2@melamine formaldehyde resin(MF) microcapsule on the flame retardancy and smoke suppression properties of polyvinyl chloride(PVC) membranes were analyzed by limiting oxygen index(LOI), horizontal and vertical burning test, smoke density(SDR) test, SEM and TG instrument.The results show that ZnSnO3@Mg(OH)2 and ZnSnO3@Mg(OH)2@MF microcapsules can effectively enhance the flame retardancy, smoke suppression, anti-dripping and self-extinguishing properties of PVC membranes.The LOI value of ZnSnO3@Mg(OH)2/PVC and ZnSnO3@Mg(OH)2@MF/PVC membrane composites obviously increases, with increasing the content of the microcapsules.However, when the content of the microcapsules increases, the smoke density and self-extinguishing time of ZnSnO3@Mg(OH)2/PVC and ZnSnO3@Mg(OH)2@MF/PVC membrane composites decreases.The TG results show that the initial degradation temperature of ZnSnO3@Mg(OH)2/PVC and ZnSnO3@Mg(OH)2@MF/PVC membrane composites move to low temperature and the amount of residual carbon increases with the content of the microcapsules.The SEM micrographs of residual carbon of ZnSnO3@Mg(OH)2/PVC and ZnSnO3@Mg(OH)2@MF/PVC membrane composites show that the addition of the microcapsules effectively promotes the form compact carbon layer of ZnSnO3@Mg(OH)2/PVC and ZnSnO3@Mg(OH)2@MF/PVC membrane composites during burning, which not only can inhibit oxygen and heat to go into the PVC bulk, but also inhibit combustion gases to go out the PVC bulk.SEM and tensile strength results show that double layer microcapsule can availably improve the dispersion and compatibility between inorganic particles and PVC matrix.