ISSN:
0887-6266
Keywords:
polystyrene
;
poly(2,6-dimethyl-1,4-phenylene oxide)
;
blend
;
molecular relaxation
;
low temperature relaxations
;
Physics
;
Polymer and Materials Science
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Physics
Notes:
Molecular relaxation behavior in terms of the α, β, and γ transitions of miscible PS/PPO blends has been studied by means of DMTA and preliminary work has been carried out using DSC. From DSC and DMTA (by tan δ), the observed α relaxation (Tα or Tg) of PS, PPO, and the blends, which are intermediate between the constituents, are in good agreement with earlier reports by others. In addition, the β transition (Tβ) of PS at 0.03 Hz and 1 Hz is observed at -30 and 20°C, respectively, while the γ relaxation (Tγ) is not observed at either frequency. The Tβ of PPO is 30°C at 0.03 Hz and is not observed at 1 Hz, while the Tγ is -85°C at 0.03 Hz and -70°C at 1 Hz. On the other hand, blend composition-independent β or γ relaxation observed in the blends may be a consequence of the absence of intra- or intermolecular interaction between the constituents at low temperature. Thus it is suggested that at low temperature, the β relaxation of PS be influenced solely by the local motion of the phenylene ring, and that the β or γ relaxation of PPO be predominated by the local cooperative motions of several monomer units or the rotational motion of the methyl group in PPO. © 1998 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 36: 1981-1986, 1998
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
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