The Reaction Mechanism of Ring-opening Polymerization of ε-Caprolactone Using Bis(benzoylacetonato)zirconium(IV) Catalyst With PM3 Semi-Empirical Method

Abstract

Acknowledged that polycaprolactone (PCL) is one of the prospective polymer category. This is due to PCL has a great mechanical properties, biodegradability, and excellent mixing ability with various other polymers. The effective technique to get PCL is through the ring opening polymerization (ROP) of caprolactone (ε-CL) using metal catalyst. The aims of this research was to determine a reasonable reaction mechanism of the ROP of ε-CL using bis(benzoylacetonato)zirconium(IV) chloride catalyst. In this investigation the PM3 semi-empirical method was assigned to calculate the monomer, intermediate structures, and polymer structure. Then, to compute and visualize geometry structure was employed by using the HyperChem 8.0 program. This software operates on the Windows 07 system. The calculation results imply that to get PCL using bis(benzoylacetonato)zirconium(IV) catalyst required a few steps i.e. coordination ε-CL in metal center, χ-CL deprotonation, the insertion of ε–CL, and propagation of the chain.