Please use this identifier to cite or link to this item: http://hdl.handle.net/1959.3/224605

Title

Creep behavior of PLA-based biodegradable plastic exposed to a hydrocarbon liquid

Author(s)

Widiastuti, Indah;  Sbarski, Igor;  Masood, S. H.

Abstract

This study explores the effect of hydrocarbon liquid on creep behavior of polylactic acid (PLA)-based plastic. Evolution of the mechanical properties of the material was investigated experimentally by measurement of creep under tensile load. Tensile creep behavior was studied with a constant load over a temperature range from 30 to 50°C using specimens containing different levels of liquid. It was shown that the hydrocarbon liquid diffusion obeys the Fickian law of diffusion. The viscoelastic properties vary with temperature and these properties dramatically decrease above the glass transition temperature (Tg). Significant decreases in modulus and in the peak of tan δ were observed with an increase in liquid concentration at low temperatures. In contrast, at high temperatures, drier material recorded lower storage modulus. However, only small changes of Tg were recorded. Dependence of compliance on temperature was observed in the creep test at all levels of liquid content. With respect to drier samples, it was noted that the high liquid content material had a lower rate of increasing creep strain with temperature. Therefore, at elevated temperatures, higher creep strain of dry specimens was observed compared to those with a higher liquid content. The improvement of creep resistance and stiffening of material at high temperatures can be attributed to the significant increase of crystallinity fraction induced by liquid absorption. Understanding the effect of liquid diffusion in conjunction with temperature provides useful information for assessment of the potential use of this biodegradable plastic in load-bearing applications exposed to an organic liquid.

Publication type

Journal article

Research centre

Swinburne University of Technology. Faculty of Engineering and Industrial Sciences. Industrial Research Institute Swinburne

Source

Journal of Applied Polymer Science, Vol. 127, no. 4 (Feb 2013), pp. 2654-2660

Publication year

2013

FOR Code(s)

03 Chemical Sciences;  09 Engineering

Keyword(s)

Biodegradable;  Creep;  Crystallization;  Diffusion;  Viscosity and viscoelasticity

Publisher

Wiley Periodicals

ISSN

0021-8995

Publisher URL

http://dx.doi.org/10.1002/app.37575

Copyright

Copyright © 2012 Wiley Periodicals, Inc.

Peer reviewed