Synthesis of isopropenylbenzyl-terminated macromonomers and preparation of polymer brushes by anionic homopolymerization

摘要

Isopropenylbenzyl-terminated polystyrene (PS) macromonomers were synthesized by anionic addition in a two-stage process using styrene and 1,4-diisopropenyl-benzene (DIPB) in benzene. The reaction products of polystyryl anions with DIPB provided PS macromonomer possessing less than two isopropenylbenzyl groups at the propagating end under the condition of being in hydrocarbon solvent at 25degreesC (ceiling temperature) because of the anionic equilibrium nature. Subsequently, anionic homopolymerization of such macromonomers was carried out in tetrahydrofuran (THF) at -78degreesC using anionic initiators to prepare the polymer brushes. The conversion of polymer brushes was very low (ca. 5%). Moreover, the degree of polymerization (DP) was less than 50. The low concentration of propagating chain ends seemed to affect the formation of polymer brushes. (C) 2003 Wiley Periodicals, Inc. [References: 22]