可分散性纳米二氧化硅增强硅橡胶

Silicone rubber reinforced by a dispersible nano-silica

采用表面经过硅烷偶联剂原位修饰的纳米二氧化硅增强硅橡胶。通过扫描电子显微镜和Payne效应考察了纳米二氧化硅在硅橡胶中的分散特性;用DSC分析了复合体系的低温结晶行为;考察了填料对硅橡胶力学性能的影响。结果表明,由于修饰后纳米颗粒表面非极性有机基团的存在和表面能的降低,无须加入分散剂,纳米颗粒就能在硅橡胶中有较好的分散;在各自最优添加量时,DNS-3链状纳米二氧化硅增强的硅橡胶相对于气相法二氧化硅增强的硅橡胶在拉伸强度、撕裂强度及断裂伸长率上有显著提高;DNS-2纳米二氧化硅增强性能与气相法二氧化硅的相当,但前者混炼胶黏度较小,有较好的加工性。

A novel nano-silica surface-modified by silane was used as a reinforcing filler for HTV（heat vulcanization） silicone rubber. The dispersion morphologies and network structure of the composites were analysed by scanning electronic microscopy （SEM） and Payne effect; the crystal behavior at low temperature was studied by differential scanning calorimetry（DSC）. And the effect of these fillers on the mechanical properties of silicone rubber was investigated. Because the surface of these nanoparticles was enwrapped by apolar methyl , they can disperse in the rubber perfectly without adding any dispersant. The results indicate that at respective optimum content, the catenarian nano-silica （DNS-3） has evidently better reinforcement to silicone rubber in the tensile strength, tear strength and elongation at break than the silica nanoparticle synthesized by aerosol method （A-200）. The DNS-2 nano-silica has a similar reinforcing effect to nano-silica compared with A-200, but the gross rubber of the DNS-2 system was softer and has better processability than that of A-200.