Ishak KA, Velayutham TS, Annuar MSM, Sirajudeen AAO. Structure-property interpretation of biological polyhydroxyalkanoates with different monomeric composition: Dielectric spectroscopy investigation.
Int J Biol Macromol 2020;
169:311-320. [PMID:
33340632 DOI:
10.1016/j.ijbiomac.2020.12.090]
[Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2020] [Revised: 12/01/2020] [Accepted: 12/11/2020] [Indexed: 10/22/2022]
Abstract
Dielectric spectroscopy is employed to study the relaxation phenomena in natural polyhydroxyalkanoates (PHAs) upon temperature and frequency variations. Effects of PHAs molecular structure on the relaxation, arising from the differences in monomeric composition, are investigated under identical conditions in a frequency range of 10-2-106 Hz, and at different temperatures. All PHA samples showed different dielectric response at different temperature. Primary α-relaxation signals are observed at temperature corresponding to the glass transition temperature. On the other hand, secondary β- and γ-relaxations are detected at low temperatures, and attributed to local motions of polar groups and small segments of the polymer chain. The dielectric properties of representative PHA samples are compared and discussed.
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