Ethylene/hindered phenol substituted norbornene copolymers: Synthesis and NMR structural determination

A new family of ethylene-based copolymers with controlled amounts of a norbornene comonomer (NArOH) bearing a stabilizing antioxidant functionality (2,6-di-tert-butyl phenol) was prepared. Due to unavoidable exo/endo equilibrium operative in NArOH comonomer, a complete and detailed NMR assignment of the structure of the prepared ethylene/NArOH copolymers was carried out for the determination of the exo/endo ratio inside the polymer. These novel functionalized comonomers can be considered suitable starting material for preparing ethylene-based copolymers, with tunable comonomer content, as non-releasing macromolecular antioxidant additives for specific application in safe food and/or drug packaging