Microwave-assisted synthesis of Poly(glycerol sebacate): Temperature-Controlled approaches for enhanced properties

Abstract

Poly(glycerol sebacate) (PGS) is a biocompatible, bioresorbable, and biodegradable elastomer obtained through a two-step process: pre-polymer synthesis and crosslinking. However, its conventional synthesis requires prolonged heating under an inert atmosphere, making it time-consuming and energy-intensive. Although synthesizing PGS pre-polymers in a domestic microwave oven offers a low-cost alternative that simplifies the production of this biomaterial, previous studies have reported that the resulting polymers exhibit poor properties. This study investigates the influence of the temperature reached by the mixture during microwave-assisted synthesis on obtaining a pre-polymer with enhanced properties. Two synthesis approaches were investigated: one that limits the maximum reaction temperature to 120 °C (S1) and another that allows temperatures up to 170 °C (S2). The thermal, physical, and chemical properties of pre-polymers and elastomers were compared using differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR), titration, and swelling tests. The results showed that limiting the reaction temperature to 120 °C significantly reduced glycerol volatilization, resulting in a pre-polymer with a higher degree of esterification. Although the swelling percentage indicated a lower crosslinking density in S1-derived elastomer, no excessive glycerol loss was observed. Based on these results, a PGS pre-polymer with preserved chemical characteristics can be synthesized using a domestic microwave, yielding elastomers with notable properties, offering a more efficient and cost-effective alternative to conventional methods.