| dc.description.abstract | Polyester such as PCL and PLA are common products of lactone ring-opening polymerization. Due to their good biocompatibility and ease of degradation, they have been widely used in packaging materials and medical applications. Alkaline earth metals, which have lower toxicity, are readily available, and inexpensive, suitable as catalysts and have been widely used in the field of ring-opening polymerization. In this study, we used alkaline earth metal (Mg, Ca, Sr) catalysts to conduct ring-opening polymerization reactions at room temperature. By adding benzyl alcohol as an initiator, the catalysts generated alkaline earth metal benzyl alkoxide during the reaction. This method allowed the ring-opening of ε-caprolactone (ε-CL), δ-valerolactone (δ-VL), and (within 10 minutes) L-lactide (L-LA) , respectively to be completed in an extremely short time (1 minute), achieving conversion rates of over 90%. The resulting polymers exhibited narrow dispersity: PCL (optimal Đ 1.39), PVL (optimal Đ...), and PLA (optimal Đ 1.09). We conducted a kinetic study of the polymerization reactions, finding that the concentration of these lactone monomers followed second-order kinetics. The reaction rates were PCL Mg < Ca < Sr and PLA Ca < Sr < Mg. These research results demonstrate that alkaline earth metal catalysts exhibit excellent catalytic activity under mild conditions for ring-opening polymerization reactions and maintain good controlled polymerization. | en_US |