Effects of crystallinity on thermally stimulated current and complex permittivity of poly(L-lactide)

S. Hikosaka, H. Ishikawa, Y. Ohki

Research output: Chapter in Book/Report/Conference proceedingConference contribution

11 Citations (Scopus)

Abstract

Recently poly(L-lactide) synthesized from starch is attracting much attention as a biodegradable polymer. In this paper, effects of crystallinity on dielectric properties of PLLA were studied by preparing four kinds of PLLA samples with different crystallinities. A thermally stimulated polarization current (TSPC) peak was found to appear in all the samples at temperatures around 65 to 70 °C, which is due to the glass transition. The magnitude of the TSPC peak was found to be in the reverse order of crystallinity. This is presumably because the segmental-mo de relaxation, which brings about the TSPC, is restricted more 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, while the other due to the normal-mode relaxation. Moreover, all the samples show a drastic increase in the real part of complex permittivity and have a peak in its imaginary part 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 around 65 to 70 °C. Therefore, the increase in the real part and the peak in the imaginary part are ascribable to the segmental-mode relaxation.

Original languageEnglish
Title of host publication2008 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2008
Pages497-500
Number of pages4
DOIs
Publication statusPublished - 2008 Dec 1
Event2008 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2008 - Quebec City, QC, Canada
Duration: 2008 Oct 262008 Oct 29

Publication series

NameAnnual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP
ISSN (Print)0084-9162

Conference

Conference2008 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2008
CountryCanada
CityQuebec City, QC
Period08/10/2608/10/29

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ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Electrical and Electronic Engineering

Cite this

Hikosaka, S., Ishikawa, H., & Ohki, Y. (2008). Effects of crystallinity on thermally stimulated current and complex permittivity of poly(L-lactide). In 2008 Annual Report Conference on Electrical Insulation and Dielectric Phenomena, CEIDP 2008 (pp. 497-500). [4772773] (Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP). https://doi.org/10.1109/CEIDP.2008.4772773