A versatile method for the synthesis of poly(glycolic acid): high solubility and tunable molecular weights

Poly(glycolic acid) (PGA) is an important biopolymer, especially in medical applications because of its suitable mechanical, biocompatible, and biodegradable properties. PGA can degrade within weeks, depending on its molecular weight. Production of high molecular weight PGA is important to achieve sufficient mechanical stability for biomedical applications. High molecular weight PGA is difficult to obtain by direct condensation of the related carboxylic acids; therefore, polyglycolide is typically made by ring opening polymerization of the cyclic diester glycolide. However, this procedure is restrictive because of the high cost of the raw material (glycolide) and the associated high energy consumption. Here, we describe the synthesis of PGA via an azeotropic distillation method that enables tunable molecular weights. The synthesized PGA is highly soluble in organic solvents and degrades faster than reference PGA. We described the synthesis of PGA via an azeotropic distillation method that enables tunable molecular weights. This alternative method produces a white powdered PGA rather than a waxy brown product that is obtained by conventional melt-solid condensation methods. Additionally, improved solubility renders this method useful for producing soluble high molecular weight PGA for further applications. Highly crystalline PGA with a high molecular weight (Mn = 32,100 g/mol) was obtained with a homogenous polydispersity index of 1.2–1.4.