Molecular Dynamics of PGA Bioabsorbable Polymer During Isothermal Cold Crystallization |
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| Authors: | Galder Kortaberria Amaia Jimeno Puy Arruti Koro de la Caba Pedro Remiro Arantxa Eceiza Iñaki Mondragon |
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| Affiliation: | “Materials + Technologies” Group, Departamento de Ingeniería Química y Medio Ambiente, Escuela Universitaria Politécnica, Universidad del País Vasco/Euskal Herriko Unibertsitatea, Pza. Europa 1, 20018 San Sebastian (Spain) |
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| Abstract: | An investigation was carried out on the molecular dynamics of poly(glycolide) (PGA) in its completely amorphous state and during isothermal cold crystallization. Experimental results were generated over a wide range of frequency and temperature by broad-band dielectric spectroscopy (DRS). The variation of the average relaxation time (defined as τ= ½πfmax where fmax is the frequency at maximum loss for the main α relaxation) has been studied during cold crystallization and the temperature dependence of this average relaxation time for completely amorphous and crystallized samples has been analyzed. This behaviour has been modelled by Havriliak-Negami and Vogel-Fulcher equations. The sensitiveness of the segmental dynamics to the degree of crystallinity has been analyzed, taking into account the relaxing segments and the amorphous layers between lamellae. Supporting evidence about the thermal behaviour of the polymers has been obtained with DSC. Complementarily, the evolution of the morphologies obtained during crystallization processes has been followed by optical microscopy. |
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| Keywords: | biopolymers crystallization dielectric relaxation spectroscopy molecular dynamics relaxation time |
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