Polymerization processes with high reproducibility, traceability, and nontoxic compounds are required for biomedical applications. Here an automated solvent-free polymerization of hyperbranched polyglycerol has been established on a multiple-hundred gram scale. Performed is an anionic ring-opening multibranching (ROMB) polymerization with slow addition of glycidol. The solvent-free approach avoids commonly used organic solvents during the polymerization and work-up. Due to the automation of the polymerization process a high reproducibility and traceability is accomplished. The used reactor is equipped with an anchor stirrer and stirrer control, which measures the applied torque. A linear correlation of the increasing torque and the degree of polymerization is observed, which can be used to monitor the molecular weight in situ during the polymerization.
