The formation of poly(ester–urea) networks in the absence of isocyanate monomers

Abstract

The polymerization of N, N′ carbonylbis (caprolactam) (CBC) and polyol in the presence of alcoholate as catalyst produced cross-linked poly(ester–urea)s via ring opening addition reaction. In contrast to conventional synthetic routes, the use of non-toxic CBC eliminates the need for toxic isocyanate-based monomers. The structure of the molecules resulting from model reactions was confirmed using FT-IR and 1H- and 13C-NMR spectroscopy. Poly(ester–urea) networks exhibit rubber-like mechanical properties and high-temperature stability. Cell adhesion and cell growth on the polymers evidenced the high biocompatibility of the material. Degradation of the poly(ester–urea)s was investigated at 70°C in neutral and basic aqueous solution. The degradation depends on the swelling behavior of the samples. Mechanical properties, good biocompatibility, and degradation behavior of the CBC/polyol-based polymers make them interesting materials for biomedical applications.