Nanofillers In Polyproylene : The Effect of the Aspect Ratio of Silica Nanofillers on the Rheology of Polypropylene

Polymers have become indispensable in our everyday life. They are used in a broad range of applications as a result of its ease of processing, low price and a combination of advantageous properties. The final performance of polymers is dictated by the chemical structure obtained during synthesis and by the processing conditions. The majority of synthetic polymers are processed via the melt. Low molecular weight is required for processing, while for desirable properties, high molecular weight is indispensable, making polymers an area of compromises. Addition of fillers is one of the ways to improve the material properties. As a result of their large surface to volume ratio, additives can improve the flow behavior, the thermal stability, the toughness and/or stiffness etc. Many researchers have used micrometer-sized fillers, but nowadays the focus has switched to nanometer-sized fillers, such as carbon nanotubes and nano-clays. The technological outcome of these nanocomposites can be advantageous for processing techniques like injection molding; still, the main problem for nanocomposites is nanoparticle dispersion.