• Xiao Yan Yang
  • Shao Shuai Liu
  • Alexander V. Korobko
  • Stephen J. Picken
  • Nicolaas A.M. Besseling

Dielectric relaxation spectroscopy (DRS) of poly(ε-caprolactone) with different draw ratios showed that the mobility of polymer chains in the amorphous part decreases as the draw ratio increases. The activation energy of the α process, which corresponds to the dynamic glass transition, increases upon drawing. The enlarged gap between the activation energies of the α process and the β process results in a change of continuity at the crossover between the high temperature a process and the α and β processes. At low drawing ratios the a process connects with the β process, while at the highest drawing ratio in our measurements, the a process is continuous with the α process. This is consistent with X-ray diffraction results that indicate that upon drawing the polymer chains in the amorphous part align and densify upon drawing. As the draw ratio increases, the α relaxation broadens and decreases its intensity, indicating an increasing heterogeneity. We observed slope changes in the α traces, when the temperature decreases below that at which τα ≈ 1 s. This may indicate the glass transition from the ‘rubbery’ state to the non-equilibrium glassy state.

Original languageEnglish
Pages (from-to)665-674
Number of pages10
JournalChinese Journal of Polymer Science (English Edition)
Issue number5
Publication statusPublished - 1 May 2018

    Research areas

  • Dielectric relaxation spectroscopy, Molecular mobility, Semicrystalline polymer

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