Microwave-assisted one-pot copolymerization of cyclic monomers and ethyl diazoacetate

The present contribution describes an innovation in the copolymerization of cyclic monomers, ε -caprolactam ( ε -CL) and 2,2-dimethyltrimethylene carbonate (DTC), with ethyl diazoacetate (EDA). The characterizations of the obtained copolymers, poly(EA- ran -EDA- ran-ε -CL) and poly(EA- ran -EDA- ran -DTC) (where EA refers to the ethyl acetate group from EDA after nitrogen release), were performed using 1 H NMR and 13 C NMR spectroscopies and size exclusion chromatography. Under optimized conditions, the copolymer of ε -CL with EDA possessing a number-average molar mass ( M n ) of 1300 g mol −1 and dispersity of 2.12 as well as that of DTC with EDA with M n of 8000 g mol −1 and dispersity of 1.47 were obtained. The incorporation of the azo group in the obtained copolymers was determined from the results of elemental analysis (3.30–10.22% nitrogen) and Fourier transform infrared spectroscopy. Furthermore, the thermal properties of the obtained copolymers were examined using differential scanning calorimetry. X-ray diffraction results showed that the synthesized copolymers were amorphous. © 2014 Society of Chemical Industry