Although Ziegler–Natta (ZN) catalysts play a major role in the polyolefin market, true understanding of their properties at molecular level is still missing. In particular, there lack knowledge on electronic Ti sites. Theoretical calculations predict that electron density sites precatalysts correlates with activation energy for olefin insertion Ti-alkyl bond generated these after by Al-alkyls. ...

This study was conducted in the Khartoum refinery Algylee to properties of polypropylene (grade 113 &114) which are produced by addition technique; they used refined propylene from Liquefied Petroleum Gas and Ziegler-Natta catalyst. The samples were taken (1-15)/08/2010 three features (powder, granulates, specimens). Both grades homopolymer isotactic polypropylene. They checked component li...

In a survey based on the biographical sketches, obituary notes and eulogies of notable scientists, eight were identified as belonging to an elite group, having authored more than 1000 research publications, which include books, monographs and patents. They were, in chronological order, Thomas Alva Edison, Paul Karrer, Margaret Mead, Giulio Natta, Hans Selye, Herbert C Brown, Tetsuji Kametani an...