Synthesis and Characterization of Biodegradable Polyester by Ring-Opening Polymerization (ROP) Using Different Catalyst Systems

In this study, biodegradable polyethylene glycol (PEG)-based block copolymer polyester was synthesized and evaluated by ring-opening polymerization (ROP). Poly(ethylene glycol-b-ɛ-caprolactone) [PEG-b-PCL] block copolymer was prepared by ring-opening polymerization of ɛ-caprolactone (ɛ-CL) in the presence of polyethylene glycol (400 Da, 2000 Da, 3000 Da) as an initiator, employing two catalyst systems: dibutyltin dilaurate (DBTDL) and tin (II) 2-ethylhexanoate (Sn(Oct)2). Polymerization was conducted under both dispersion and bulk conditions to investigate the effect of solvent on copolymer molecular weight, dispersity, and polymerization time. The resulting biodegradable block copolymer polyester was characterized by Fourier transform infrared spectroscopy (FTIR), 1H nuclear magnetic resonance spectroscopy (1H-NMR), and gel permeation chromatography (GPC).