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Molecular architectures of four‐arm star‐shaped styrene‐butadiene copolymer
Author(s) -
Zhang Lina,
Ma Zhaocheng,
Xiong Xiaopeng,
Xu Xiaojuan,
Ma Rui,
Li Yang
Publication year - 2005
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/app.21533
Subject(s) - radius of gyration , copolymer , star (game theory) , branching (polymer chemistry) , polymer chemistry , intrinsic viscosity , tetrahydrofuran , hydrodynamic radius , materials science , styrene , polystyrene , styrene butadiene , molar mass distribution , viscometer , gyration , analytical chemistry (journal) , viscosity , chemistry , physics , composite material , polymer , chromatography , mathematics , organic chemistry , astrophysics , geometry , solvent
To understand the molecular architectures of styrene‐butadiene four‐arm star (SBS) copolymers, a size exclusion chromatography combined with laser light scattering (SEC‐LLS) has been used to determine their weight‐average molecular weight ( M w ) and radius of gyration (〈 S 2 〉 1/2 ), and a new method for the establishment of the Mark‐Houwink equation from one sample has been developed. Based on the Flory viscosity theory, we successfully have reduced the 〈 S 2 〉 1/2 values of numberless fractions estimated from many experimental points in the SEC chromatogram to intrinsic viscosities ([η]). For the first time, the dependences of 〈 S 2 〉 1/2 and [η] on M w for the four‐arm star SBS in tetrahydrofuran at 25°C were found, respectively, to be 〈 S 2 〉 1/2 = 2.62 × 10 −2 M w 0.54(nm) and [η] = 3.68 × 10 −2 M w 0.64(mL/g) in the M w range from 1.4 × 10 5 to 3.0 × 10 5 . From data of [η] and 〈 S 2 〉 1/2 for linear and star SBS, we have obtained the information about the branching, namely, the ratios ( g and g ′) of 〈 S 2 〉 and [η] for star SBS to that of the linear SBS of the same molecular weight, which agree with theoretical predictions. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 96: 961–965, 2005