Effect of novel TiCl4/MgCl2 catalyst on propylene polymerization - Effect of diketone inner electron donor with different substituents on performance of the catalyst

A series of novel MgCl2-supported catalysts with diketone compounds as inner electron donor were prepared; the effects of the catalysts on propylene polymerization were studied. Polymerization temperature of 40°C and n(Al)/n(Ti) ratio of 100 were taken as the best conditions for propylene slurry polymerization reaction in the presence of the catalyst The catalyst with electron donor of 2, 4-pentadione bearing a substitute in the 3-position gained the advantage over its counterpart without a substitute in the same position in catalytic activity. Similarly, the polymer prepared with the former was superior to the polymer made with the latter in isotactic index. The larger the volume of the substitute in 3-position of the diketone as inner electron donor, the higher the activity of the catalyst and the higher the isotactic index of the resultant polymer.