Neat PGS by Conventional Method. PGS was synthesized in two steps. First, a 1:1 molar ratio of glycerol (99%, Sigma-Aldrich) and sebacic acid (SA; 99%, SigmaAldrich) were mixed together at room temperature, and the mixture was placed in a convection oven under nitrogen atmosphere at 120, 130, or 140 °C for 24 h. The prepolymerization process resulted in waxy or liquid-like materials when cooled to room temperature. Then, the prepolymers were dissolved in tetrahydrofuran (THF) to form prepolymer/THF solution (0.5 g/mL in THF), and then it was cast into the molds made of aluminum foil (length × width = 10 × 10 cm2). The prepolymers were placed in a vacuum oven, which was then slowly evacuated to ∼1 mTorr. The specimens were cured for 6−66 h at the same temperature as the prepolymerization process.