The structure of PHAs composed of 3-hydroxy fatty acids is shown in Fig. 3. The most common polymers,with a structure given in Fig. 3, are shown in Table 1.
The value of n in Figs 3 and 4a,b depends on the pendant group and the micro-organisms in which the polymer is produced.
It is typically between 100 and 30 000 (Lee 1996).