Geometrical structure of star polymers in solution

✍ Scribed by Koji Ishizu; Tomohiro Ono; Satoshi Uchida

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 514 KB
• Volume: 198
• Category: Article
• ISSN: 1022-1352
• DOI: 10.1002/macp.1997.021981022

✦ Synopsis

Abstract

Polyisoprene (PI) stars were prepared by copolymerizing PI‐lithium with divinyl‐benzene (DVB) in heptane. The dilute‐solution properties of these stars (arm numbers f = 43–237) were characterized by static and dynamic light scattering (SLS and QELS), and viscometric measurements. From the results of QELS, it could be concluded that the non‐uniformity of the number of arms in PI starts is relatively narrow due to the organized copolymerization of ω‐functional PI‐lithium with DVB in uniform micelles. The ratio of the radius of gyration over the Stokes radius (R~G~/R~H~) in cyclohexane decreases gradually and approaches unity as f becomes large. Even PI stars with multiarms behave not as neat hard spheres but as soft spheres which in good solvents were penetratable near the edges.