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D. Jamanek, Z. Wieczorek, I. Leszczyńska, W. Skupiński

Hydrogenation of C=C bonds in styrene-isoprene-styrene block copolymers in the presence

of monocyclopentadienyl titanium(IV) catalytic systems (in English)

Polimery 2012, No 4, 266


DOI: dx.doi.org/10.14314/polimery.2012.266

Summary

Hydrogenation of C=C bonds in styrene-isoprene-styrene (SIS) block copolymers in the presence of CpTiCl2(OC6H4Y-p)/BuLi and CpTiCl2(OC6H4Y-p)/Et3Al catalytic systems (Cp = cyclopentadienyl, Bu = butyl, Et = ethyl; Y = Cl, H, OCH3) was investigated. All of the catalytic systems were active in these reactions. Their activity depended on the kind of the metal alkyl, the copolymer composition, reaction time, temperature and hydrogen pressure. It was established that access of catalytic species to the C=C bonds in the isoprene blocks is the most important factor in the hydrogenation efficiency. The smallest steric hindrances occur when phenoxy ligands in the catalytic systems are unsubstituted (Y = H) and styrene-isoprene diblocks (SI) are present in the SIS copolymer. Thus, the catalytic systems CpTiCl2(OC6H4Cl)/BuLi were the most active in Kraton® D-1161 copolymers hydrogenation.


Key words: styrene-isoprene-styrene copolymer, cyclopentadienyl titanium complexes, hydrogenation, buthyllithium, triethylaluminum

e-mail: wincenty.skupinski@ichp.pl

D. Jamanek, Z. Wieczorek, I. Leszczyńska, W. Skupiński (158.5 KB)
Hydrogenation of C=C bonds in styrene-isoprene-styrene block copolymers in the presence of monocyclopentadienyl titanium(IV) catalytic systems (in English)