纳米SiO_2粒子表面官能团对尼龙6原位聚合的影响

研究了无机纳米粒子表面反应性官能团对尼龙 6 纳米SiO2 原位聚合的影响 .红外光谱和热重分析结果证实了无论对SiO2 进行表面处理与否 ,在原位聚合过程中其表面均能形成一定量的接枝聚合物 .随表面反应性官能团数目的增加 ,SiO2 的表面接枝率呈上升趋势 .与纯的尼龙 6相比 ,带有不同反应性官能团的纳米SiO2 的加入使复合产物的分子量呈下降的趋势 .对应于复合体系中可能发生的反应 ,提出了几种可能的表面接枝的键接方式 .力学性能测试结果显示经表面处理的SiO2 的加入能同时提高复合物的强度和韧性 ,而加入未处理的SiO2 时 ,材料强度可得到提高 ,但韧性明显降低 ,表明由偶联剂处理引入的柔性界面层的存在对于复合材料的力学性能有重要的影响

THE INFLUENCE OF SURFACE FUNCTIONAL GROUPS OF NANO-SiO2 ON NYLON 6 in situ POLYMERIZATION

The influence of different surface functional groups of nano SiO 2 on nylon 6 in situ polymerization was investigated.FTIR and TGA measurements of silicas isolated from the composites showed that surface grafting was formed during polymerization of silica particles with or without silane pretreatment on the surface,and the percentage of grafting increased with increasing amount of surface functional groups.Compared with pure nylon 6,the presence of silicas with various functional groups resulted in a decreasing tendency of the average molecular weight of nylon 6 in the composites.According to the possibly occurred reactions in the composite systems several bonding styles of surface grafting were proposed.Mechanical tests revealed that the addition of silane treated silica improved the strength and toughness of the composite materials simultaneously,whereas the addition of untreated silica improved the strength at the sacrifice of toughness,indicating the importance of the flexible interlayers introduced by silane treatment.