The Effect of Nano-Silica on Rheological Behavior and Toughness of Modified Polypropylene

In this article a kindof nanometer silicon dioxide material which prepared by co-precipitation method was used to improve the properties of ordinary raw material of polypropylene packing film. The results show that the nanometer silicon dioxide material not only greatly increased the notched izod impact strength of modified PP but also increased its flexural modulus and flexural strength and when the content of nanometer silicon dioxide material is less than 1%, the HDT of the modified PP is also lightly increased, and the same time other mechanical properties like tensile stress stay as before. Non-isothermal crystallization behavior of modified PP by this nanometer silicon dioxide material was investigated by differential scanning calorimeter. According to the study on the melt rheology,at a low shear rate, apparent viscosities of PP modified by the nanometer silicon dioxide material were lower than that of pure PP, which proves the nano-silicon dioxide materials can improve the processability of PP and will be good for the producing of PP packaging film. SEM and XPS method has carried on the attribute to the size of SiO2 and its distribution.