Synthesis, chemical structure and properties of cross-linked poly(esterurethanes) based on unsaturated oligo(alkyleneester)diols

Abstract

The cross-linked poly(esterurethanes) (PEU) based on unsaturated oligo(alkyleneester)diol (OAE) are presented. OAE was prepared from adipic acid, maleic anhydride and ethylene glycol and then characterized by elemental analysis, FTIR, 1H NMR and 13C NMR spectroscopy in account of double bonds and -COOH end groups. The synthesis of PEU was conducted in two steps. In the first step the prepolymers, containing free NCO or OH groups, were obtained via the reaction of OAE with 4,4′-diphenylmethane diisocyanate (MDI) used in excess. The cross-linking was achieved in the next step, in which the prepolymers were dissolved in methyl methacrylate (MMA) of concentrations in the range of 30 to 50 wt% in the presence of 1 wt% of methyl ethyl peroxide and 0.003 wt% of cobalt (II) 2-ethylhexanoate. It is proved that both chemical structure and MDI content in prepolymer influence the static and dynamic mechanical properties and thermal stability of the poly(esterurethanes).