Scale-up of microwave-assisted polymerizations in batch mode:: The cationic ring-opening polymerization of 2-ethyl-2-oxazoline

The use of microwave heating in polymer science is a rapidly growing field of research leading to faster and cleaner polymerization procedures. However, the majority of the investigations are performed at small scales (approximate to 1 mL), which is far away from potential commercial applications of microwave-assisted polymerizations. In addition, it has been shown in organic chemistry that microwave-assisted reaction protocols can be directly scaled without the need for process optimization. In this contribution, we have investigated the direct scaling of microwave-assisted polymerization procedures under pressure conditions using the cationic ring-opening polymerization of 2-ethyl-2-oxazoline as the model system. This polymerization was performed at scales ranging from 4.0 mmol (1 mL) to 1.0 mol (250 mL) in different microwave synthesizers covering both monomode and multimode devices.