Carbon Dioxide-Based Biodegradable Polycarbonate Macrodiols: Synthesis, Structure, and Performance

Using 1,4-butanediol (BDO) as a chain transfer agent and a metal-free Lewis acid-base catalyst, polycarbonate macrodiols (PECDLs) with arbitrarily adjustable carbonate content were successfully synthesized via the direct copolymerization of ethylene oxide (EO) and carbon dioxide (CO₂). The optimal reaction conditions were established through orthogonal experiments, and the effects of reaction pressure, reaction time, and reaction temperature on the copolymerization reaction were investigated. The molecular weight of the oligocarbonate diols can be conveniently and precisely controlled within the range of 1000-5000 g/mol, and the carbonate content can be controlled within 3-90%. PECDLs with a carbonate content lower than 70% exhibit significant water solubility. Due to the extremely low cost of carbon dioxide and epoxide, PECDLs with different compositions show extremely extensive attraction for many practical applications in the polyurethane industry, PVC environmentally friendly plasticizers, and novel biodegradable surfactants. This technology certainly triggers hot topics in both carbon dioxide utilization and biodegradable chemical feedstuffs.