Relaxation behaviour in bulk PIMA and PIMA-PMMA copolymer near Tg

  • F. Alvarez
  • J. Colmenero
  • C. H. Wang
  • G. Fytas
Part of the Progress in Colloid & Polymer Science book series (PROGCOLLOID, volume 91)


The relaxation processes in the glass-transition temperature range of bulk PIMA and PIMA-PMMA copolymer have been studied by means of Photon Correlation Spectroscopy (PCS) and dielectric spectroscopy (DR). The experimental results were treated in a conistent way employing an inverse Laplace transform analysis of the density C ϱ(t) and dipole moment ϕμ(t) autocorrelation functions. The latter was obtained from the ɛ″ (ω) data utilizing a recently developed algorithm. For bulk PIMA, C ϱ(t) clearly shows two distinct relaxation processes, whereas ϕμ(t) is dominated by the slower (α-) relaxation mode. The fast process in C ϱ(t) is probably related to the rotation of the rigid isobornyl group about the C-O bond.

The copolymer displays a β-relaxation process and a slower α-relaxation dielectric process in agreement with the PCS results. The molecular origin of these processes is outlined.

Key words

PIMA PMMA PCS dielectric spectroscopy relaxation 


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Copyright information

© Dr. Dietrich Steinkopff Verlag GmbH & Co. KG 1993

Authors and Affiliations

  • F. Alvarez
    • 3
  • J. Colmenero
    • 3
  • C. H. Wang
    • 1
  • G. Fytas
    • 2
  1. 1.Department of ChemistryUniversity of NebraskaLincolnUSA
  2. 2.Forth-Iesl, HeraklionCreteGreece
  3. 3.Departamento de Física de MaterialesUPV/EHUSan SebastiánSpain

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