聚碳硅烷协效氢氧化镁阻燃聚乙烯复合材料的残炭结构演变

Structure Evolution of Residual Char of Polycarbosilane/Magnesium Hydroxide Flame Retardant Polyethylene Composites

以氢氧化镁等为代表的无卤阻燃聚烯烃材料由于具有无毒、环保等特点,在阻燃领域中一直占有重要地位。鉴于其阻燃机理决定的低阻燃效率需要高添加量的特点及分解后自身残留固相产物较多,相应的阻燃复合材料燃烧后能够产生较多的残炭,为陶瓷化提供了物质基础,但以氢氧化镁为主的陶瓷化阻燃聚烯烃材料研究较少。陶瓷化前驱体材料——聚碳硅烷具有较高的陶瓷化产率,常用于制备具有复杂结构的陶瓷构件,但其用于聚烯烃阻燃的报道较少。本工作将聚碳硅烷与氢氧化镁复合制备了阻燃聚乙烯复合材料,研究了聚碳硅烷对复合材料凝聚相炭层结构的影响。结果表明,聚碳硅烷能够有效地将氧化镁颗粒粘结在一起形成具有特殊结构的陶瓷化炭层。

Halogen⁃free flame retardant polyolefin materials represented by magnesium hydroxide flame retardant have been playing an important role in the flame retardant field because of their non⁃toxic and eco⁃friendly characteristics.In view of its high addition result from its low flame retardant efficiency determined by the flame retardant mechanism and the large number of solid phase products left after decomposition,more residual char of its composites will be left after combustion,which provides material basis for the ceramization.However,the ceramifiable flame retardant polyolefin materials based on magnesium hydroxide have been less studied.Polymer ceramic precursor materials-polycarbosilane,has high ceramic yield,which is often used to produce ceramic components with complex structures,but its application in flame retardant of polyolefin is rarely reported.In this paper,flame⁃retardant polyethylene(PE)composites were prepared with polycarbosilane and magnesium hydroxide,the effect of polycarbosilane on the structure of condensed char layer of the composites was studied.The results show that polycarbosilane can effectively bond magnesium oxide particles together and produce a ceramic carbon layer with special structure.