Reinforcement of Epoxy Polymers with Micro/Nanosized and Mesostructured Silicas

摘要

Polymer nanocomposites exhibit improved performance properties compared to pristine polymers and conventional composites due to the enhanced interfacial interactions between the polymer and the high available external surface of the inorganic nano-particles. The mesoporous silicas which exhibit high intra-particle surface area (ca. 500-1300 m~2/g) and ordered meso-structure (with pore size of 2-50 nm) were initially described in the early 90's and were aimed for use as catalysts or catalyst supports, and later on as adsorbents, drug carriers, etc. Apart from the tunable structural characteristics, mesoporous silica nanoparticles have also a hydroxyl-rich surface, they can be easily functionalized with organic molecules and they aggregate with weaker interparticle forces compared to other types of micro/nanoparticles (e.g. clays and carbon nanotubes). So, mesoporous silicas could be used as potential polymer reinforcing agents utilizing the large intra-particle silica surface and offering unique properties to the resulting polymer nanocomposite materials. In the present study, two types of mesoporous silicas and two types of novel silica micro/nanoparticles where used for the reinforcement of rubbery epoxy polymers. The nanocomposites were tested for their mechanical and thermal properties. The effect of silica loading and the interaction of epoxy resin with functional groups on the silica surface were specifically investigated.