Polyhydroxyalkanoates are natural polyesters produced by certain bacteria.
Depending on the type of bacteria and the cultivation conditions, it is possible to obtain a whole range of PHAs with different properties.
Depending on the nature of the side carbon chain R and the number (x) of
carbons in the repeating unit constituting the main chain, it will be possible to play on their flexibility, extensibility or crystallinity. The most common PHAs are polyhydroxybutyrate (PHB) and poly(hydroxybutyrate-co-valerate) (PHBV)