Styrene-free unsaturated polyester resins derived from itaconic acid curable by cobalt-free accelerators

Abstract A series of polyester prepolymers was synthesized from itaconic acid, phthalic anhydride, propane-1,2-diol and diethylene glycol by condensation polymerization. The use acid as a source unsaturation (instead more common maleic anhydride giving fumarate moieties) enabled to replace styrene reactive diluent methyl methacrylate. Room temperature curing model resin initiated butanone peroxide in combination with several cobalt-, iron- vanadium-based accelerators. Measurements gelation time exothermic behavior thermally isolated installation revealed very promising catalytic properties for oxidovanadium(IV) dibutylphosphate. In follow-up tests, mechanical the unsaturated were tuned variation propane-1,2-diol/diethylene ratio composition acrylate/methacrylate diluent. Mixtures methacrylate secondary crosslinking agents (e.g., ethylene dimethacrylate, triethyleneglycol dimethacrylate trimethylolpropane triacrylate) improve ultimate tensile strength, Young’s modulus, toughness impact toughness. Reported experimental data indicate that described styrene- cobalt-free system is reduction health ecological issues currently used resins curable at room temperature. Graphical