Elucidating the structure-property relations and crystallization kinetics of polyhydroxyalkanoate biopolymers

Activity: Talk or presentationTalk or presentation at a conference

Description

Polyhydroxyalkanoates (PHAs) are biocompatible polymers produced through biosynthesis, potentially from renewable feedstocks. Fundamental knowledge on the structure-property relations of PHAs is still lacking, especially for less common copolymers such as poly(3-hydroxybutyrate-co-4-hydroxybutyrate), which is a very promising material for high value-added applications in the biomedical industry. A systematic study on P(3HB-co-4HB) is thus needed, although this is complicated due to the lack of commercial sample availability [1]. Therefore, shake-flask fermentation by Cupriavidus sp. USMAA2-4 was performed to produce P(3HB-co-4HB) samples with varying structural properties. By varying the synthesis conditions, including the carbon sources fed to the bacterial cultures, samples with varying 4HB molar fraction were obtained. Extensive thermomechanical analysis of these samples was performed and the crystallization kinetics of P(3HB-co-4HB) were studied by differential scanning calorimetry (DSC). The experimentally observed crystallization kinetics were modelled with an adapted Haudin-Chenot numerical model [2]. This model accurately describes the crystallization kinetics of P(3HB-co-4HB) with varying composition over a large temperature range. Slow crystallization is known to be an issue for the industrial melt processing of PHA materials, e.g. injection molding, where rapid polymer crystallization is critical. Characterization of the crystallization as function of time and temperature is therefore crucial to acquire fundamental understanding of the relation between structure, processing and properties. This project is the first to explore the variation of the kinetic and physical crystallization parameters, obtained through numerical modelling of experimentally observed crystallization kinetics, with P(3HB-co-4HB) composition.
Period30 Jun 2022
Event titleEuropean polymer congress EPF 2022
Event typeConference
LocationPrague, Czech Republic
Degree of RecognitionInternational