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Viscoelastic behavior of poly(butyl methacrylate) densely grafted on silica nanoparticles
Author(s) -
Hayashida Kenichi,
Tanaka Hiromitsu,
Watanabe Osamu
Publication year - 2011
Publication title -
polymer international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.592
H-Index - 105
eISSN - 1097-0126
pISSN - 0959-8103
DOI - 10.1002/pi.3062
Subject(s) - materials science , fumed silica , polymer , methacrylate , nanoparticle , nanocomposite , dynamic mechanical analysis , viscoelasticity , atom transfer radical polymerization , composite material , polymerization , chemical engineering , polymer chemistry , nanotechnology , engineering
A series of poly(butyl methacrylate)s (PBMAs) with various molar masses (33 000–270 000 g mol −1 ), which were densely grafted on fumed silica nanoparticles (PBMA–SiO 2 ), were synthesized by surface‐initiated atom transfer radical polymerization. The dynamic viscoelastic behavior of PBMA–SiO 2 was systematically investigated in the solid and molten states with oscillatory strains, and compared to that of a conventional nanocomposite (PBMA/SiO 2 ). The storage moduli of PBMA–SiO 2 and PBMA/SiO 2 are equivalent in the solid state, whereas the storage modulus of PBMA–SiO 2 is lower than that of PBMA/SiO 2 in the molten state, especially at high silica loading. This is because the formation of a network structure composed of the silica nanoparticles in PBMA–SiO 2 is strongly suppressed by the polymer brushes on the particles. In contrast, even at low silica loading, the PBMA–SiO 2 system exhibits a gel‐like behavior resulting from a steric repulsion between the composite particles, because all of the tethered polymers behave as bound polymers. Copyright © 2011 Society of Chemical Industry