Polyhydroxyalkanoates (PHAs) are a class of biodegradable polymers which can be produced via bacterial synthesis. They have garnered interest due to their potential as a biodegradable alternative to petroleum-based plastics. PHA molecules have been shown to have a helical morphology, which organize into spherulitic crystal structures. The most common, naturally occurring PHA, poly(3-hydroxybutyrate) (PHB), typically has a crystallinity of up to 75-85% in its homopolymer form. The resulting material is thus brittle and has a narrow processing window. However, a broad range of mechanical properties has been achieved with the inclusion of varying quantities of 3-hydroxyhexanoate (HHx) units to form the polymer P(HB-co-HHx).
Zhu, Morgan and Neal, Matt, "Reorganization Behavior in Low Crystallinity Poly(Hydroxybutyrate-Co-Hydroxyhexanoate)" (2014). Clare Boothe Luce Undergraduate Research Scholars. 3.