阻燃苎麻/酚醛树脂复合材料的制备及性能

采用磷酸酯类和氮磷类两种不同类型的阻燃剂处理苎麻织物, 并与酚醛树脂复合制备苎麻/酚醛树脂层压板, 发现氮磷类阻燃剂能够更好地提高酚醛层压板的阻燃性能。氮磷类阻燃剂处理苎麻织物后使层压板的极限氧 指数由25.2%提高到39.1%, 并达到垂直燃烧试验UL94的V0级, 而磷酸酯类处理只能使极限氧指数提高到27.8%。锥形量热试验发现氮磷类的阻燃剂处理后使层压板的残炭量增加, 点燃时间大幅度延长, 而峰值热释放速率和平均烟密度则显著降低。同时, 阻燃剂处理苎麻织物时, 对麻纤维结构的破坏很小, 因此对材料力学性能影响很小。 

Preparation and properties of flame retarded ramie/phenolic resin composites

The ramie fabric was treated with two different types of flame retardants, namely phosphate type and nitrogen-phosphorous type, and composed with phenolic resin to prepare ramie/phenolic resin laminate. The flame retardancy of the laminate treated by nitrogen-phosphorous type flame retardant is better than that treated by phosphate type flame retardant. The limiting oxygen index (LOI) of the laminate with nitrogen-phosphorous type treatment increases from 25.2% to 39.1%, and reaches the V0 level in UL94 vertical burning test, while LOI of the laminate with the phosphate type treatment only increases to 27.8%. Cone calorimeter tests show that the laminates with the nitrogen-phosphorous type treatment have increased char residue, extended ignition time and decreased peak heat release rate and average smoke density. It is also found that the mechanical properties of the laminates are not changed because of the little damage on the fiber structure of ramie fabric with the flame retardant treatment.