Melting points polyhydroxyalkanoates

The family of polyhydroxyalkanoates (PHA) exhibits a wide variety of mechanical properties from hard crystalline to elastic, depending on the composition of monomer units [12]. Solid-state poly(3-hydroxybutyrate) (P(3HB)) is a compact right-handed helix with a two-fold screw axis (i.e. two monomer units complete one turn of the helix) and a fibre repeat of 0.596 nm [13]. The stereoregularity of P(3HB) makes it a highty crystalline material. Its melting point is around 177°C close to that of polypropylene, with which it has other similar properties, although the biopolymer is stiffer and more brittle. 

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