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Influence of Morphology on the Dynamics of the PB Glass Process in SBS
Author(s) -
Mohammady Sayed Z.,
Mansour Ashraf A.,
Stoll Bernhard,
von Soden Wolfgang,
Pechhold Wolfgang
Publication year - 2001
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 - 10.1002/1521-3935(20010601)202:9<1883::aid-macp1883>3.0.co;2-c
Subject(s) - polybutadiene , materials science , differential scanning calorimetry , phase (matter) , polymer , copolymer , morphology (biology) , dielectric , composite material , dynamic mechanical analysis , elastomer , transmission electron microscopy , polymer chemistry , glass transition , chemical engineering , chemistry , thermodynamics , nanotechnology , organic chemistry , physics , genetics , optoelectronics , biology , engineering
The molecular dynamics of two styrene‐butadiene‐styrene block copolymers with different morphologies and stiffness but with the same phase dimensions (thickness of domains) were investigated. Dynamic mechanical and dielectric measurements were done over wide ranges of frequencies, 10 –4 –10 Hz and 0.1–10 5 Hz, and temperatures from –95°C to –17°C and from –93°C to –72°C, respectively. In addition, differential scanning calorimetry (DSC), transmission electron microscopy (TEM) and stress‐strain behavior investigations were also used in the characterization. The dielectric and dynamic mechanical results showed that the dynamics of the glass process of the polybutadiene phase (PB phase)in both polymers is the same. Therefore, it could be concluded that the difference in morphology does not influence the dynamics of the glass process of the polybutadiene phase in these materials, where the geometrical confinement applied on the PB phase is the same in both polymers. Fitting of the activation curves of the glass process, to evaluate the length of the cooperative reorienting region of the PB phase, delivered a length of 10.3 nm. This result means that the domains seen by TEM (9 & 20 nm) are formed either from one or by association of two structural units (≈ 10 nm).