Lactides and Lactones Yielding Eco-Friendly and Biocompatible Polymers by Metal-Catalyzed Ring-Opening Polymerization

Currently, there is a growing interest in the development of suitable methods for the preparation of eco-friendly and biocompatible materials in order to increase environmental protection and reduce human health risk. Therefore, this mini-review summarizes several studies involving lactides and lactones as monomers for the synthesis of biodegradable and biocompatible polymers via metal-catalyzed Ring-Opening Polymerization (ROP). Hence, synthetic approaches involving mono, bi and trinuclear metallic catalysts, with different catalytic activity, were reviewed. Complexes mostly based on metals such as Na, Mg, Al, Ti, Zn are considered. Generally, from ROP reactions, it has been found that conversion, stereoselectivity, number-average molar mass (Mn) and dispersity of the molar mass (Ð) of polymers are influenced by the type of monomer, the characteristics of the catalyst, the nature of the solvent, temperature and reaction time. Additionally, the polymer properties can also be controlled by varying the molar ratios between the monomer and the initiating system. Thus, this review may be found helpful for the scientific community and students involved in research in different areas of chemistry such as organic chemistry, inorganic chemistry, polymers chemistry, and materials science. The survey covers selected data published between 2017 and 2020; however, previous relevant reports were also studied.