Plasticization effects of epoxidized vegetable oils on mechanical properties of poly(3‐hydroxybutyrate)

<jats:title>Abstract</jats:title><jats:p>The effect of various epoxidized vegetable oils as potential plasticizers for poly(3‐hydroxybutyrate) (<jats:styled-content style="fixed-case">PHB</jats:styled-content>) was evaluated in terms of changes in mechanical and thermal properties and morphology. <jats:styled-content style="fixed-case">PHB</jats:styled-content> is a biodegradable aliphatic polyester obtained from bacterial fermentation. High stiffness and fragility are two of its main drawbacks. To overcome this behaviour, <jats:styled-content style="fixed-case">PHB</jats:styled-content> was plasticized with various amounts of two different epoxidized vegetable oils: epoxidized linseed oil (<jats:styled-content style="fixed-case">ELO</jats:styled-content>) and epoxidized soybean oil (<jats:styled-content style="fixed-case">ESBO</jats:styled-content>). The total <jats:styled-content style="fixed-case">ELO</jats:styled-content> and <jats:styled-content style="fixed-case">ESBO</jats:styled-content> content varied in the range 5 phr (per hundred resin) to 20 phr and plasticized <jats:styled-content style="fixed-case">PHB</jats:styled-content> materials were obtained by melt extrusion and compounding followed by injection moulding. The results show that the plasticizing effect provided by <jats:styled-content style="fixed-case">ELO</jats:styled-content> is more efficient than that by <jats:styled-content style="fixed-case">ESBO</jats:styled-content> with balanced properties at a concentration of 10 phr <jats:styled-content style="fixed-case">ELO</jats:styled-content>. <jats:styled-content style="fixed-case">ELO</jats:styled-content> addition leads to an improvement in mechanical ductile properties with a noticeable increase in elongation at break and impact absorbed energy. With regard to thermal properties, the addition of both <jats:styled-content style="fixed-case">ELO</jats:styled-content> and <jats:styled-content style="fixed-case">ESBO</jats:styled-content> leads to a marked increase in thermal stability of <jats:styled-content style="fixed-case">PHB</jats:styled-content>. All these findings suggest that addition of 10 phr <jats:styled-content style="fixed-case">ELO</jats:styled-content> leads to optimized <jats:styled-content style="fixed-case">PHB</jats:styled-content> formulations with potential uses in technical applications. © 2016 Society of Chemical Industry</jats:p>