Effect of carboxylated poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) block copolymer on nanostructured unsaturated polyester resin

A carboxylated poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) (PEO-b-PPO-b-PEO) block copolymer was used to fabricate nanostructured unsaturated polyester materials. The commercial PEO-b- PPO-b-PEO block copolymer was carboxylated using succinic and maleic anhydrides in order to improve the miscibility between the carboxylated PEO blocks and the unsaturated polyester matrix and to hinder microphase separation of the PEO blocks during the Reaction Induced Phase Separation (RIPS). Atomic force microscopy (AFM) measurements were employed to detect the well-defined and stable structure of the nanostructured unsaturated polyester matrix. Furthermore, the strong effect of the chemical modification of the PEO-b-PPO-b-PEO block copolymer on the morphology, transparency and mechanical properties of the designed novel nanostructured thermosetting systems based on the unsaturated polyester was also investigated. The designed materials open up a new strategy of preparation of well-defined nanostructured systems modified with chemically modified block copolymers with enhanced toughness.