(eta(5)-indenyl)trichlorotitanium-catalyzed copolymerization of styrene and styrenic macromonomer carrying a functional group

Abstract

Styrenic macromonomers with/without a silyloxy-functional group were synthesized via chain-end functionalization using 4-vinylbenzyl chloride as a terminating agent insec-butyllithium-initiated polymerization of styrene. The yields were 92 mol% for the silyloxy group and 88 mol% for the styrenic unit. Crystalline polystyrene-g-amorphous polystyrenes were synthesized by (eta(5)-indenyl)-trichlorotitanium ((Ind)TiCl3)-catalyzed copolymerizations of the macromonomers with styrene in the presence of methylaluminoxane (MAO) in toluene at 40 degrees C. The macromonomer having alpha,alpha'-bis(4-[tert-butyldimethylsilyloxy]phenyl) group was also utilized for the preparation of a precursor of hydroxyl-functionalized syndiotactic polystyrene. The obtained polymers were characterized by a combination of H-1, C-13 NMR spectroscopic, size exclusion chromatographic, and differential scanning calorimetric analysis. The (Ind)TiCl3-catalyzed copolymerization of styrene with the macromonomer carrying the silyloxy functional group was found to be an efficient method to modify syndiotactic polystyrene without a great loss of physical property by controlling the feed ratio of the macromonomer.