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Geometrical structure of star polymers in solution
Author(s) -
Ishizu Koji,
Ono Tomohiro,
Uchida Satoshi
Publication year - 1997
Publication title -
macromolecular chemistry and physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.57
H-Index - 112
eISSN - 1521-3935
pISSN - 1022-1352
DOI - 10.1002/macp.1997.021981022
Subject(s) - radius of gyration , cyclohexane , hydrodynamic radius , copolymer , polymer chemistry , gyration , micelle , polymer , heptane , lithium (medication) , star (game theory) , stars , radius , materials science , star polymer , dynamic light scattering , chemistry , physics , crystallography , composite material , thermodynamics , nanoparticle , nanotechnology , organic chemistry , geometry , astrophysics , mathematics , computer security , endocrinology , computer science , medicine , aqueous solution
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.