Biocompatible Catalysts for Lactide Polymerization-Catalyst Activity, Racemization Effect, and Optimization of the Polymerization Based On Design of Experiments

An original synthesis of Ca, Mg, and Zn 2-ethylhexanoate (octoate) obtained by reaction between metallic powder with 2-ethylhexanoic acid was achieved. The activities of obtaining biocompatible catalysts of lactide polymerization were tested. The most active catalyst was zinc 2-ethylhexanoate (ZnOct(2)), and the lowest activity catalyst was calcium 2-ethylhexanoate (CaOct(2)). The ROP process was successfully optimized by using the design of the experiment. Polylactide with M-w = 82.3 kg/mol with lactide conversion up to 85% and 8% content of D-lactic acid has been obtained. Thus, the obtained polylactides can be used in medical and pharmaceutical devices.