Shahriar. Arjmand - Department of Chemistry, Islamic Azad University, Jam Branch, Iran
Jamshid Askari - Department of Chemistry, Islamic Azad University, Jam Branch, Iran

Polypropylene is considered as one of the most important plastic types because of its substantial supreme properties such as high melting temperature, good chemical resistance and desirable mechanical properties, and achieving desired properties of Polypropylene is a significant activity, besides, gaining this properties isthe most important economical factor in reactor polymerization which gives a considerable curve for performance cost polypropylene. In this paper, polypropylene properties, finding physical factor_ the form, and other factors such as molecular weight _ the type of used catalyst and molecular mass which would be expanded to properties of final polypropylene application, are all described. The state of mechanical changes _thermal and photic changes of polymer which are closely dependant to foresaid factors_ is also discussed inpresent paper, and this indicates the path toward achieving desired quality

Polypropylene ¸ Stereo specificity Stereochemistry ،Ziegler-Natta catalysts، Atacticity