Preparation And Mechanical Properties Of The Nanopowder / Polypropylene Composites Research

In this thesis we have studied the toughening and strengthing modifications of polypropylene (PP) by nano-particle such as CaC03) Si02 and Ti02. The performance of modified polypropylene and the modifying mechanism have been introduced. We have also explored the furthest dosage of Titanate coupling agent in CaC03/PP and the influence of coupling agent to the composites by the determination of the mechanical properties. Furthermore, we compared the mechanical properties between the modified nano-CaC03/PP and unmodified nano-CaC03/PP.We have investigated the composites by means of mechanical testing, DSC, XRD, FT-IR, TEM, SEM, etc. The relation between the structure and property of the composites has been discussed in this thesis. We studied the nano-particles by means of LS particles size analysis , we also studied the modified nano- CaC03 by means of FT-IR.The result show that PP filled with nano-particles has better mechanical performances than which filled with micron-particles. There is some furthest dosage of Titanate coupling agent in CaC03/PP. The mechanical properties of the modified nano~CaC03/PP is better than that of unmodified nano-CaC03/PP, especially the impact strength has been improved greatly. But when the dosage of nano-particles is too much, those nano particles will accumulate and this will lead to decreasing of strength of the material.Through investigated of XRD and DSC, we found that ?-PP was formed by addition of nano-particles. The distribution of modified and unmodified nano-particles in PP were studied by means of TEM, it showed that modified nano-particles dispersed much better than the unmodified nano-particles. The improved contribution of nano-particles lead to more(3 -PP formed and microscopic damage, all those structural changes caused the improvement of the mechanical properties.