Effects of crystallinity on dielectric properties of poly(L-lactide)

Saki Hikosaka, Hiroto Ishikawa, Yoshimichi Ohki

    Research output: Contribution to journalArticle

    12 Citations (Scopus)

    Abstract

    Poly(L-lactide) is attracting much attention as a biodegradable polymer. In this paper, effects of crystallinity on dielectric properties of PLLA are discussed. At 80 $C, which is above the glass transition temperature (= about 60 °C), the conductivity increases with a decrease in crystallinity. A thermally stimulated polarization current (TSPC) peak, which seems to be due to segmental-mode relaxation, appears in all the samples at temperatures around 65 to 70 °C, and it becomes smaller as the crystallinity increases. All the samples show two thermally stimulated depolarization current (TSDC) peaks at around 65 °C and around 90 to 100 °C. The lower-temperature peak seems to be due to the segmental-mode relaxation, and the other due to the normal-mode relaxation. Moreover, all the samples show a drastic increase in the real part of the complex permittivity (εr′) and a peak in its imaginary part (Ïμr.) at frequencies from 10-1 to 104 Hz, depending on the measurement temperature. The crystallinity dependencies of the two parts are similar to those of the TSPC and TSDC peaks at around 65 to 70 °C. Therefore, the increase in εr′ and the peak in εr″ are ascribable to the segmental-mode relaxation.

    Original languageEnglish
    Pages (from-to)1-8
    Number of pages8
    JournalElectronics and Communications in Japan
    Volume94
    Issue number7
    DOIs
    Publication statusPublished - 2011 Jul

    Fingerprint

    Dielectric Properties
    Depolarization
    Dielectric properties
    dielectric properties
    crystallinity
    Polarization
    Biodegradable polymers
    Temperature measurement
    Permittivity
    depolarization
    Temperature
    Temperature Measurement
    Normal Modes
    Glass Transition
    Conductivity
    Polymers
    polarization
    Decrease
    glass transition temperature
    temperature measurement

    Keywords

    • Biodegradable polymer
    • complex permittivity
    • crystallinity
    • electrical conduction
    • glass transition
    • thermally stimulated current

    ASJC Scopus subject areas

    • Electrical and Electronic Engineering
    • Computer Networks and Communications
    • Physics and Astronomy(all)
    • Signal Processing
    • Applied Mathematics

    Cite this

    Effects of crystallinity on dielectric properties of poly(L-lactide). / Hikosaka, Saki; Ishikawa, Hiroto; Ohki, Yoshimichi.

    In: Electronics and Communications in Japan, Vol. 94, No. 7, 07.2011, p. 1-8.

    Research output: Contribution to journalArticle

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