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Design your own elastomeric or stereoregular polymer
Author(s) -
Shmulinson Michal,
Volkis Victoria,
Lisovskii Anatoli,
Nelkenbaum Elza,
Eisen Moris S.
Publication year - 2002
Publication title -
polymers for advanced technologies
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.61
H-Index - 90
eISSN - 1099-1581
pISSN - 1042-7147
DOI - 10.1002/pat.256
Subject(s) - cationic polymerization , polymerization , cyclopentadienyl complex , monomer , polypropylene , polymer chemistry , materials science , elastomer , polymer , metallocene , toluene , alkylation , medicinal chemistry , chemistry , catalysis , organic chemistry , composite material
This study reports the synthesis and activity as precatalysts for the polymerization of propylene of five racemic group 4 complexes, cis‐[p‐R′C 6 H 4 C(NR) 2 ] 2 MX 2 (R′ = CH 3 , R = SiMe 3 , M = Ti, X = Cl ( 1 ); R′ = CH 3 , R = SiMe 3 , M = Zr, X = Cl ( 2 ); R′ = H, R = i‐pr, M = Zr, X = Cl ( 3 ); R′ = CH 3 , R = SiMe 3 , M = Zr, X = CH 3 ( 4 )) and (acac) 2 MCl 2 (M = Ti ( 5 ), M = Zr ( 6 )) (acac = acetylacetone). The hydrocarbyl complex 4 was prepared by the alkylation of the corresponding complex 2 with MeLi·LiBr. Reaction of complex 4 with B(C 6 F 5 ) 3 or all complexes with MAO (MAO = methylalumoxane) results in the formation of a “cationic” intermediate complex which rapidly reacts with the incoming monomer. Some of the complexes catalyze the stereoregular polymerization of propylene only under pressure in either toluene or CH 2 Cl 2 , producing polypropylene with very large isotacticities (mmmm % = ∼95–98), high melting points (140–154 °C) and similar molecular weights as compared with cyclopentadienyl complexes, whereas complex 5 is active for the polymerization of elastomeric polypropylene. Copyright © 2003 John Wiley & Sons, Ltd.