화학공학소재연구정보센터
Macromolecules, Vol.35, No.6, 2055-2062, 2002
Star-block-linear-block-star triblock (pom-pom) polystyrene by convergent living anionic polymerization
Star-block-linear-block-star triblock polystyrene polymers with identical stars at each end of a linear block (pom-pom polymers) were synthesized by the convergent living anionic polymerization method. The sequential synthesis involved first the formation of a living anionic polystyrene star with a hyperbranched core via continuous addition of coupling agent, 4-(chlorodimethylsilyl)styrene, to living polystyrene chains. Subsequent addition of styrene monomer to the living polystyrene star anions produced star-block-linear diblock polystyrene anions that were then coupled with dichlorodimethylsilane to make the architectural triblock. The obtained pom-pom polymers were purified by fractionation. Gel permeation chromatography-multiangle laser light scattering characterization clearly showed the molecular weight changes due to the progression of polymerization. The star-block-linear-block-star triblock copolymers were characterized by NMR (H-1 and Si-29) spectroscopy and dilute solution viscometry. The architectural triblock copolymers demonstrate interesting dilute solution properties.