Novel precursors for production of 3-hydroxyvalerate-containing poly[(<b><i>R</i></b>)-hydroxyalkanoate]s

Abstract

Polyhydroxyalkanoates (PHAs) with tailored properties are needed to meet consumer demands regarding the use of eco-compatible biobased polymeric materials and relevant plastic items. Inserting 3-hydroxvalerate (3HV) monomeric units in PHA biopolyesters results in poly[(R)-3-hydroxybutyrate-co-(R)-3-hydroxyvalerate] (PHBHV) copolyesters aimed at their conversion into production of biodegradable eco-friendly plastic items. As inexpensive novel precursor substrate structurally related to 3HV, a mixture of odd-numbered carboxylic acids with 9–17 carbon atoms was produced by oxidative ozonolysis of alkenes. This mixture was successfully applied for biomediated PHBHV production by Cupriavidus necator. Applying this mixture as carbon substrate, a molar 3HV fraction exceeding 0.12 was obtained. The isolated copolyesters featured a low degree of crystallinity, narrow molar mass distribution, and low melting temperatures. These properties should make application of the novel 3HV-precursors interesting for large-scale production of easily processable copolyesters.