Ring-opening polymerization of 1,4,8-trioxaspiro-[4.6]-9-undecanone: A route to novel molecular architectures for biodegradable aliphatic polyesters

The ring-opening polymerization of 1,4,8-trioxaspiro-4.6]-9-undecanone (TOSUO) initiated by aluminum isopropoxide, Al(OⁱPr)₃, is typically “living” and allows random and block copolyesters of predictable molecular weight and composition to be prepared. Deacetalization of the polyester chains is complete, and reduction of the accordingly formed ketone groups into hydroxyl groups as well. No chain scission is observed when these two derivatization reactions are carried out. The potential of these novel functional aliphatic polyesters has been discussed as drug colloidal vectors and macroinitiators for the synthesis of biodegradable and biocompatible comb, graft and even hyperbranched polymers.