4. Biodegradable polyesters derived from petrochemicals

4.1 Poly(butylene adipate terephthalate) or PBAT

PBAT is produced through condensation reactions between 1,4-butanediol, adipic acid (or hexanedioic acid), and terephthalic acid (Figure 5 ). It is an aliphatic-aromatic copolyester composed of rigid segments due to the terephthalic acid units and more flexible segments due to the units derived from 1,4-butanediol and adipic acid. Organometallic derivatives such as zinc, tin, or titanium can be used as polycondensation catalysts. The synthesis of PBAT can be divided into three successive steps: