铝离子改性MF/PVA阻燃纤维的研究

Research of aluminum ion-modified MF/PVA flame-retardant fiber

以三聚氰胺和甲醛为反应物,分别以氯化铵和硫酸铝为催化剂制得三聚氰胺甲醛(MF)树脂和Al^(3+)-MF树脂,再分别将MF树脂和Al^(3+)-MF树脂与聚乙烯醇(PVA)按质量比3∶7进行湿法纺丝,制得MF/PVA,Al^(3+)-MF/PVA阻燃复合纤维;同时将凝胶态的MF/PVA复合纤维在质量分数为50%的硫酸铝溶液中浸泡得到Al^(3+)吸附改性MF/PVA复合纤维(MF/PVA-Al^(3+)纤维);研究了不同Al^(3+)改性方式对MF/PVA复合纤维性能的影响,并分析了Al^(3+)与MF树脂的协同阻燃机理。结果表明:Al^(3+)加入使MF/PVA纤维热性能提高,力学性能稍有降低,基本不影响其使用性能;MF/PVA纤维、Al^(3+)-MF/PVA纤维、(MF-PVA)-Al^(3+)纤维在600℃时的残炭率分别为10.99%,34.53%,26.75%;断裂强度分别为2.83,2.68,2.64c N/dtex;Al^(3+)与MF树脂之间存在明显的协同阻燃作用,能够明显提高MF树脂对PVA纤维的阻燃效果;两种不同Al^(3+)改性方式对复合纤维阻燃性的影响差异不大,Al^(3+)-MF/PVA复合纤维和MF/PVA-Al^(3+)复合纤维的极限氧指数(LOI)都能达到33%;两者阻燃机理由于Al^(3+)分布方式的不同而有所差别,Al^(3+)-MF/PVA纤维主要呈现出气相阻燃机理,(MF/PVA)-Al^(3+)纤维主要呈现出凝聚相阻燃机理。

Melamine formaldehyde （MF） resin and Al^3＋-MF resin were prepared by using melamine and formaldehyde as re-actants and ammonium chloride or aluminum sulfate as a catalyst , and were separately wet-spun with polyvinyl alcohol （ PVA） at the mass ratio of 3：7 to produce MF/PVA and Al^3＋-MF/PVA flame-retardant composite fibers .The MF/PVA composite fiber in gel state was immersed in 50%aluminum sulfate solution to obtain an Al 3＋-modified MF/PVA composite fiber （ MF/PVA-Al^3＋fiber ） .The effect of different Al 3＋modification techniques on the properties of MF/PVA composite fiber was studied .The syner-gistic flame retardant mechanism of Al 3＋and MF resin was also analyzed .The results showed that the addition of Al 3＋made the thermal property increase and the mechanical properties slightly decrease , but hardly impacted other performance of MF/PVA fi-ber;the carbon yield of MF/PVA fiber, Al^3＋-MF/PVA fiber, （MF-PVA）-Al^3＋fiber was 10.99%, 34.53%and 26.75%, and the breaking strength was 2.83, 2.68 and 2.64 cN/dtex, respectively, at 600℃;the synergistic flame retardant effect between Al^3＋and MF resin was obviously observed , which profoundly improved the flame retardance of PVA fiber;the two different Al 3＋modification techniques gave similar effects on the flame retardance of the composite fibers ;the limiting oxygen index （ LOI） val-ue of Al^3＋-MF/PVA composite fiber and MF/PVA-Al^3＋composite fiber both reached 33%; the flame retardant mechanism of these two composite fibers was different due to the different Al 3＋distribution, namely, gas-phase flame retardant mechanism for Al^3＋-MF/PVA fiber and condensed-phase flame retardant mechanism for （MF/PVA）-Al^3＋fiber.