Influence of chemical structure on the morphology and physical properties of crosslinked macromolecules synthesised by polyaddition reaction

By reacting acid polyesters with di‐epoxides and crosslinking them with anhydrides it was possible to increase the energy of deformation in the transition range by a factor of 10, compared with the conventional highly crosslinked epoxy resins. A further increase in toughness could be realised by introducing hydrogen bonds, e.g. urethane groups along the chains of the polymers. The syntheses of epoxy resins containing urethane groups are described. The physical properties of the crosslinked systems caused by different densities of the crosslinks are demonstrated and discussed.