Controlled anionic synthesis of star-shaped polystyrene by the incremental addition of divinylbenzene

• Published in: Journal of polymer science. Part A, Polymer chemistry Polymer chemistry, 2005-02, Vol.43 (4), p.870-878
• Main Authors: Lee, Hyung-Jae, Lee, Kwanyoung, Choi, Namsun
• Format: Article
• Language: English
• Subjects: anionic polymerization; Applied sciences; Exact sciences and technology; Organic polymers; Physicochemistry of polymers; Polymerization; polystyrene; Preparation, kinetics, thermodynamics, mechanism and catalysts; star polymers
• ISSN: 0887-624X; 1099-0518
• DOI: 10.1002/pola.20572

Star polystyrenes were synthesized from polystyryllithium with an incremental procedure in which equally divided portions of divinylbenzene (DVB) were added periodically. When the addition of DVB was repeated, the content of the unreacted polystyryllithium dramatically decreased, and complete conversion was readily achieved. In the conventional linking reaction, however, in which all the required amounts of DVB were added at once, there was an incomplete conversion of the arm polymer. The arm number of star polymers also continuously increased upon the subsequent addition of DVB. The incremental‐addition method effectively synthesized star polystyrene, minimizing uncoupled polystyrene and reproducibly controlling the arm number of star polystyrene without the formation of gel polymers. The intrinsic viscosity of star polystyrene was measured to determine the highly branched structure of star polystyrene prepared by incremental or one‐shot addition. © 2005 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 43: 870–878, 2005 The incremental addition of divinylbenzene (DVB) to polystyryllithium (PSLi) effectively synthesized star‐shaped polystyrene, minimizing uncoupled polystyrene and reproducibly controlling the arm number of star polystyrene without the formation of gel content.