Polycarbonate Synthesis via Ring-Opening Polymerization: Catalysts, Mechanisms, and Sustainable Strategies

Abstract

Polycarbonates are treasured because of their transparency, impact resistance, and thermal stability. They are highly utilized in biomedical, packaging, and sustainable practices. Such an increase in demand has enhanced the quest to find greener ways of synthesis. The Ring-Opening Polymerization (ROP) of cyclic carbonates has become a flexible and manageable method to synthesize Aliphatic Polycarbonates (APCs) with tunable structures to overcome the drawbacks of Aromatic Polycarbonates (ArPCs) synthesized using phosgene. The present review entails an extensive discussion of the mechanism of ROP, such as cationic, anionic, and organocatalyzed pathways. It highlights catalyst innovations, including metal complexes to metal-free organocatalysts, which minimize side reactions like backbiting and decarboxylation. In the review, the authors also discuss the main factors influencing efficiency, including ring-strains, reaction parameters, and dual-activation strategies, as well as discuss the combination of new tools like Artificial Intelligence (AI)-driven optimization and Density Functional Theory (DFT) to predictively design catalysts. Improvement of enzymatic catalysis and ionic liquids has been demonstrated to improve sustainability through the ability to use milder reaction conditions and recyclability. Despite the problems that still exist in terms of control of molecular weight and achievability of scale, rational catalyst engineering does present the prospect of high-performance, biodegradable polycarbonates. The integration of experimental and computational approaches is expected to accelerate innovation and meet the demand for eco-friendly materials in high-value sectors.