Novel well-defined star homopolymers and star-block copolymers of poly(n-hexyl isocyanate) by anionic polymerization

Anionic polymerization high-vacuum techniques and appropriate multifunctional initiators/additives were employed for the synthesis of novel star structures of poly(n-hexyl isocyanate) (PHIC). A new trifunctional initiator prepared by the reaction of tris(4-isocyanatophenyl)methane with benzyl sodium was used for the synthesis of three-arm star PHIC. Divinyl benzene and the core-first or the arm-first/ core-first (in-out) approach were utilized for the synthesis of multiarm star homopolymers, (PHIC-b-PI)n, star-block copolymers, (PHIC-b-PI)n, and miktoarm star copolymers, (PS)n(PHIC)n, where PS is polystyrene. The molecular characteristics obtained by size-exclusion chromatography, equipped with refractive index and two-angle light scattering detectors, nuclear magnetic resonance, spectroscopy, and dilute solution viscometry showed that well-defined structures were synthesized in this study. (C) 2006 Wiley Periodicals, Inc.