硅橡胶粘弹行为的微观机理

Micro-Mechanism Viscoelastic Behavior of Silicone Rubber

应用原子力显微镜(AFM)与动态力学分析仪(DMA)对三种具有不同分子链结构的硅橡胶粘弹行为及其微观机理进行了研究。结果表明,苯基侧基的引入,破坏了聚硅氧烷分子链的规整性,降低其结晶度,增强硅氧烷链间的内摩擦,使硅氧烷分子链段的弛豫与运动需要消耗更多的能量。尤其是单苯基的引入,能更好地调节苯基链节在聚硅氧烷中的分布,在有效提高硅橡胶损耗因子的同时,更好地维持着-Si-O-链的柔顺性,使制得的三元共聚甲基苯基乙烯基硅橡胶(PVMQ-2)具有优越的综合力学性能。

The micro-mechanism viscoelastic behaviors of three kinds silicone rubber with different molecular structure were studied by atomic force microscope （AFM） and dynamic mechanical analyzer （DMA） in this paper. The results show that the introduction of phenyl side groups destroyes the regularity of the silicone rubber chains,decreases the crystallinity,enhances the internal friction between the silicone rubber chains,and makes the relaxation and movement of the silicone rubber chains consuming more energy. In particular the existence of the single phenyl siloxane chains regulates the distribution of the phenyl groups in the molecular backbones playing an important role in enhancing the internal friction and improving the damping properties of silicone rubber and maintaining the flexibility of the-Si-O-chains. The ternary copolymerized methyl phenyl vinyl silicone rubber （PVMQ-2） possesses predominant mechanical property.