Synthesis, Characterization And Properties Of Star-shaped Poly (p-dioxanone)

Aliphatic polyesters, such as poly(glycolide) (PGA), poly(lactide) (PLA), poly(ε-caprolactone) (PCL) have been extensively studied for pharmacological, biomedical and environmental purposes due to their biodegradability, high drug permeability and biocompatibility. Poly(p-dioxanone)(PPDO) has its special characters comparing with other aliphatic polyesters. Except for its ultimate biodegradability due to the existence of ester bonds in polymer chains, the unique ether bonds also endue it with good flexibility.In recent years, there has been an increasing interest in the well-defined macromolecular architectures such as star polymers, hyperbranched polymers, and dendrimers. Star-shaped polymers (ssP) are branched polymers distinguished by a structure containing three or more linear arms attached to a centre core. Owing to their particular architecture, ssPs exhibit many characteristic properties. Star-shaped aliphatic polyesters may have a great potential in biomedical applications in the future.In this paper, star-shaped poly(p-dioxanone) (ssPPDO) was synthesized by the ring-opening polymerization of PDO initiated by pentaerythritol(PTOL) or trimethylolpropane(TMP) using stannous octoate as catalyst in bulk. The polymers were characterized by ¹H NMR and ¹³C NMR spectroscopy. The thermal stability of polymers was investigated by thermogravimetric analysis (TGA). The...