Ring-opening polymerization of ε-caprolactam and ε-caprolactone via microwave irradiation

A novel process for synthesizing nylon-6 and poly(epsilon-caprolactone) by microwave irradiation of the respective monomers, epsilon-caprolactam and epsilon-caprolactone, is described. The ring opening of epsilon-caprolactam to produce nylon-6 was performed in a microwave oven by the forward power being controlled to about 90-135 W in the presence of an omega-aminocaproic acid catalyst (10 mol %) and for periods of 1-3 h at temperatures varying from 250 to 280 degreesC. The ring opening of epsilon-caprolactone to produce poly(epsilon-caprolactone) was performed in a microwave oven by the forward power being controlled to about 70-100 W for a period of 2 h in the presence of stannous octoate with and without 1,4-butanediol over a temperature range of 150-200 degreesC. The yields, conditions of the reactions, and properties of the products generated relative to the thermal processes are discussed. (C) 2002 Wiley Periodicals, Inc.