View More View Less
  • 1 Universidade Nova de Lisboa REQUIMTE/CQFB, Departamento de Química, FCT Caparica Portugal 2829-516 Caparica Portugal 2829-516
  • | 2 University of Minho 3B’s Research Group – Biomaterials, Biodegradables, Biomimetics, Department of Polymer Engineering Braga Portugal 4710-053 Campus de Gualtar Braga Portugal 4710-053 Campus de Gualtar
  • | 3 University of Minho Department of Polymer Engineering Guimarães Portugal 4800-058 Campus de Azurém Guimarães Portugal 4800-058 Campus de Azurém
Restricted access

Abstract  

A detailed dielectric characterization of the relaxation modes found in a poly(L-lactic acid), PLLA, film containing 0.4 mass% of water is provided. The sub-glass relaxation process is a superposition of two processes, one highly influenced by water with activation energy of 50 kJ mol–1, and another one, with longer relaxation times and lower intensity having activation energy of 38 kJ mol–1. Dried PLLA exhibits an abnormally broad secondary β-relaxation that probably corresponds to the superposition of multiple processes. Upon water sorption the strength of the more mobile process significantly increases being shifted to lower temperatures which allows the detection of the underlying process. The glass transition relaxation process is deviated to higher frequencies almost one decade due to the water plasticizing effect. The reported results show that small quantities of water may have a profound impact in the relaxational features in PLLA, which should be taken in account when considering the properties and performance of this system.

Manuscript Submission: HERE

  • Impact Factor (2019): 2.731
  • Scimago Journal Rank (2019): 0.415
  • SJR Hirsch-Index (2019): 87
  • SJR Quartile Score (2019): Q3 Condensed Matter Physics
  • SJR Quartile Score (2019): Q3 Physical and Theoretical Chemistry
  • Impact Factor (2018): 2.471
  • Scimago Journal Rank (2018): 0.634
  • SJR Hirsch-Index (2018): 78
  • SJR Quartile Score (2018): Q2 Condensed Matter Physics
  • SJR Quartile Score (2018): Q2 Physical and Theoretical Chemistry

For subscription options, please visit the website of Springer.

Journal of Thermal Analysis and Calorimetry
Language English
Size A4
Year of
Foundation
1969
Volumes
per Year
4
Issues
per Year
24
Founder Akadémiai Kiadó
Founder's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
Publisher Akadémiai Kiadó
Springer Nature Switzerland AG
Publisher's
Address
H-1117 Budapest, Hungary 1516 Budapest, PO Box 245.
CH-6330 Cham, Switzerland Gewerbestrasse 11.
Responsible
Publisher
Chief Executive Officer, Akadémiai Kiadó
ISSN 1388-6150 (Print)
ISSN 1588-2926 (Online)

Monthly Content Usage

Abstract Views Full Text Views PDF Downloads
Jun 2021 1 0 0
Jul 2021 1 0 0
Aug 2021 0 0 0
Sep 2021 1 0 0
Oct 2021 0 0 0
Nov 2021 1 0 0
Dec 2021 0 0 0