Effect of sisal and hydrothermal ageing on the dielectric behaviour of polylactide/sisal biocomposites

QC 20170621
The dielectric properties of virgin polylactide (PLA) and its reinforced composites with different weight amounts of sisal fibres were assessed at broad temperature (from −130 °C to 130 °C) and frequency ranges (from 10−2–107 Hz), before and after being subjected to accelerated hydrothermal ageing. The synergetic effects of both the loading of sisal and hydrothermal ageing were analysed by means of dielectric relaxation spectra. The relaxation time functions were evaluated by the Havriliak-Negami model, substracting the ohmic contribution of conductivity. The intramolecular and intermolecular relaxations were respectively analysed by means of Arrhenius and Vogel-Fulcher-Tammann-Hesse thermal activation models. The addition of fibre increased the number of hydrogen bonds, which incremented the dielectric permittivity and mainly hindered the non-cooperative relaxations of the biocomposites by increasing the activation energy. Hydrothermal ageing enhanced the formation of the crystalline phase at the so-called transcrystalline region along sisal. This fact hindered the movement of the amorphous PLA fraction, and consequently decreased the dielectric permittivity and increased the dynamic fragility.

TEKNIK OCH TEKNOLOGIER Materialteknik Kompositmaterial och -teknik hsv//swe
ENGINEERING AND TECHNOLOGY Materials Engineering Composite Science and Engineering hsv//eng
Biocomposites
Crystallinity
Degradation
Dielectric spectroscopy
Dynamic fragility
Hydrothermal ageing
Natural fibre
poly(lactide) (PLA)
Segmental cooperativity
Sisal

Reig-Rodrigo, P. (author)
Teruel-Juanes, R. (author)
Kittikorn, ThorsakKTH,Fiber- och polymerteknologi,Prince of Songkla University, Thailand(Swepub:kth)u1ta2ri4 (author)
Strömberg, EmmaKTH,Fiber- och polymerteknologi(Swepub:kth)u1hnbchc (author)
Ek, MonicaKTH,Fiber- och polymerteknologi(Swepub:kth)u1hylg9m (author)
Karlsson, SigbrittKTH,Fiber- och polymerteknologi(Swepub:kth)u1g9umtq (author)
Ribes-Greus, A. (author)
KTHFiber- och polymerteknologi (creator_code:org_t)

By the author/editor: Badia, J. D.; Reig-Rodrigo, P.; Teruel-Juanes, R ...; Kittikorn, Thors ...; Strömberg, Emma; Ek, Monica; show more...; Karlsson, Sigbri ...; Ribes-Greus, A.; show less...

About the subject

ENGINEERING AND TECHNOLOGY: ENGINEERING AND ...; and Materials Engine ...; and Composite Scienc ...

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