Large-Scale Polycondensation of Lactic Acid Using Microwave Batch Reactors

Chemical processes assisted by microwave heating are attractive energy-saving processes. We applied microwave heating to the polycondensation of lactic acid, which conventionally is known as a high-energy-consuming process. We herein studied the microwave-assisted reaction at scales ranging from several tens of milliliters to several tens of liters. Poly(lactic acid) polymers with average molecular weights exceeding 10,000 were obtained after 5 h of microwave heating. Analysis of the consumed microwave power also showed that the energy used by the polycondensation per mole of substrate was saved by scaling up the reaction.