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Supported titanium catalysts based on magnesium dichloride—silicon tetraethoxide adduct for propylene polymerization
Author(s) -
Gupta V. K.,
Jain R. C.,
Ravindranathan M.
Publication year - 1997
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19970516)64:7<1445::aid-app24>3.0.co;2-u
Subject(s) - titanium tetrachloride , lewis acids and bases , catalysis , polymer chemistry , polymerization , titanium , chemistry , magnesium , alkyl , adduct , propylene oxide , materials science , organic chemistry , copolymer , polymer , ethylene oxide
Anhydrous magnesium dichloride was reacted with silicon tetraethoxide to form a solid adduct. The adduct was treated with titanium tetrachloride and an internal Lewis base to prepare supported titanium catalysts. Alkyl benzoate (PhCOOR, R = Me, Et, n ‐ Bu) or dialkyl phthalate [Ph(COOR) 2 , R = Me, Et, n ‐ Bu] was used as an internal Lewis base. The prepared catalysts (MT) in combination with triethylaluminum as a cocatalyst polymerize propylene to yield polypropylene. The nature and concentration of internal Lewis base influence the composition, specific surface area, and performance of the catalysts. The addition of diphenyl dimethoxysilane into the MT/Et 3 Al catalyst system increases the isotactic index of polypropylene from 75 to 97 at a Si/Al mol ratio of 0.05. The overall results indicate that a dialkyl phthalate‐incorporated catalyst shows better physical, chemical, and polymerization characteristics compared to a corresponding alkyl benzoate catalyst. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 64: 1445–1450, 1997