The most efficient and environmentally friendly method to synthesize a biodegradable polymer with a high molecular weight using renewable resources as starting materials is through the process of ring-opening polymerization ROP of cyclic esters derived from renewable resources, such as lactic acid, glycolic acid, and caprolactone.Lactic acid, for example, can be obtained from the fermentation of biomass feedstocks like corn, sugarcane, or cellulose. The cyclic ester of lactic acid, known as lactide, can be synthesized through the condensation and cyclization of lactic acid. Similarly, glycolic acid can be obtained from renewable resources and converted into its cyclic ester, glycolide.Ring-opening polymerization of these cyclic esters, such as lactide and glycolide, can be catalyzed by metal complexes or organic catalysts under mild conditions. This process leads to the formation of biodegradable polymers like polylactic acid PLA and polyglycolic acid PGA , which have high molecular weights and excellent mechanical properties.These biodegradable polymers are environmentally friendly as they can be degraded by microorganisms in the environment, releasing carbon dioxide and water as byproducts. Additionally, the use of renewable resources as starting materials reduces the dependency on fossil fuels and contributes to a more sustainable and circular economy.