氢氧化镁粒径对其填充三元乙丙橡胶复合材料力学性能和阻燃性能的影响

Effect of particle size of Mg(OH)_2 on mechanical and fire retarding properties of ethylene propylene diene monomer

分别以粒径为 1 0 0nm ,6 2 9,3 5 7,2 92 μm的氢氧化镁为阻燃剂和增强剂 ,加入到 1 0 0份 (质量 )三元乙丙橡胶中 ,考察了填料粒径对复合材料力学性能和阻燃性能的影响。结果表明 ,随着氢氧化镁粒径的减小 ,复合材料的力学性能逐渐提高 ,纳米复合材料的力学性能远优于微米复合材料的。采用锥形量热仪和氧指数仪研究了复合材料的阻燃性能 ,发现对于未改性氢氧化镁填充体系 ,随着粒径的减小 ,复合材料的最大热释放速率降低 ,引燃时间增长。氢氧化镁经过硅烷偶联剂 (Si 69)改性后 ,纳米复合材料的力学性能显著提高 ,最大热释放速率和引燃时间变化不大 ;而微米复合体系的力学性能和阻燃性能都无明显变化。

A novel nano-magnesium hydroxide filler(less than 100 nm) and three kinds of micro- magnesium hydroxide filler with different particle size (6.29,3.57,2.92 μm) were chosen as fire retardants and reinforcing agents, and mixed with 100 phr of ethylene propylene diene monomer (EPDM) to research the effect of particle size on the mechanical and fire retarding properties of composites. The results showed that the mechanical properties of composites with untreated filler improved with the decrease of particle size. The nanocomposites were far stronger than the micro-composites. The effect of particle size on the fire resistance of composites was investigated by cone calorimeter and oxygen index analyzer. It was shown that the particle size of filler had a certain impact on the fire resistance of composites. For the composites filled with untreated fillers, the peak value of heat rate of releasing(HRR) decreased and kindling time increased with the reducing of particle size. Surface modification of particles could remarkably improve the mechanical properties of nanocomposites, but had no effect on the peak value of HRR and kindling time of nanocomposites. The mechanical and fire retarding properties of micro-composites had no obvious change after treated.