Biodegradation of Thermoplastic and hermosetting Polyesters from Z-Protected Glutamic Acid

In a previous article,1 the development and molecular characterization of three polyesters from N-carbobenzyloxy-L-glutamic acid (ZGluOH) were reported. The polymers were a linear, heterochain polyester (ZGluOH and ethylene glycol), a crosslinked heterochain polyester (ZGluOH and diglycidyl ether of 1,4-butanediol), and a crosslinked, heterochain aromatic polyester (ZGluOH and diglycidyl ether of bisphenol A). In this manuscript, results of biodegradation studies are reported. The three polymers hydrolyzed to low molecular weight oligomers similar to the monomers with lipase. When exposed to a mixed culture of micro-organisms, the first two resins degraded to biomass and respiratory gases. The crosslinked heterochain aromatic polyester resisted microbial degradation.