Table 1: Classification of the bacterial polyesters.

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Carbon sourcePoly(3-hydroxy alkanoate) (PHA)Thermal and mechanical properties
TypeSide chain (R)Name Elongation (%)

Sugar, glucose, acetic acidShort chain lengthMethyl,PHB151705
ethylPHV

Alkanoic acids, alkanes, and alkanolsMedium chain lengthpropyl,PHHx−4060800
butyl,PHHp
pentyl,PHO
hexyl,PHN
heptylPHD

Plant oily acidsLong chain lengthMore than 14 carbon−5040Soft, sticky
per repeating unit

B: butyrate, V: valerate, Hx: hexanoate, Hp: heptanoate, O: octanoate, N: nonanoate, D: decanoate, and are glass transition and melting temperatures, respectively.