Synthesis, Properties, and Biodegradation of Sequential Poly(Ester Amide)s Containing γ-Aminobutyric Acid

Poly(ester amide)s are attracting attention because they potentially have excellent thermal and mechanical properties as well as biodegradability. In this study, we synthesized a series of novel poly(ester amide)s by introducing gamma -aminobutyric acid (GABA) regularly into polyesters, and investigated their properties and biodegradabilities. GABA is the monomer unit of biodegradable polyamide 4 (PA4). The new poly(ester amide)s were synthesized from the reaction of ammonium tosylate derivatives of alkylene bis(gamma -aminobutylate) and p-nitrophenyl esters of dicarboxylic acids. All the obtained polymers showed relatively high melting temperatures (T-m). Their thermal decomposition temperatures were improved in comparison with that of PA4 and higher enough than their T-m. The poly(ester amide)s exhibited higher biodegradability in seawater than the corresponding homopolyesters. Their biodegradabilities in activated sludge were also studied.