γ-Substituted and unsubstituted poly(ε-caprolactone)s (PCLs) are used in the field of drug delivery due to their biocompatibility and biodegradability. PCLs are mainly synthesized by the ring opening polymerization of ε-caprolactone using Sn(Oct)2. Although the Sn catalyst polymerizes unsubstituted ε-caprolactone, it fails to polymerize some of the γ-substituted ε-caprolactone monomers which connects to the lactone ring via an ester linkage. We have observed that such monomers gives predominantly a transesterified product rather than the desired polymer with the Sn catalyst. Herein, we demonstrate the catalytic activity of NdCl3●3TEP/TIBA (TEP= triethylphsphate, TIBA= triisobutylaluminum) catalytic system for the ring opening polymerization of unsubstituted and γ-substituted ε-caprolactones. γ-Substituted ε-caprolactone monomers, which were unable to polymerize with Sn(Oct)2 and organic bases such as DBU (1,8-diazabicyclo[5.4.0]undec-7-ene), were successfully polymerized with high molecular weights by using the NdCl3●3TEP/TIBA catalytic system. Copolymerization and kinetic studies for the lactones were also carried out.

Ring opening polymerization of lactones by a neodymium coordination catalyst

255th National Meeting (2018)

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.