Polymers and paper as packaging materials of irradiated food - An NMR study

Effects of ?-irradiation on synthetic polymers and paper used as packaging materials for irradiated food have been studied by NMR. Polystyrene, polybutadiene and some copolymers were studied before and after the ?-irradiation treatment and in the presence or absence of antioxidants and stabilisers. In the absence of additives, the effect of ?-irradiation on polystyrene is negligible even irradiating at high doses. In turn, the role of antioxidants and stabilisers is crucial in polybutadiene and butadiene-containing copolymers. Wood pulp paper was also studied by NMR. Preliminary measurements on ?-irradiated wood pulp sheets show a shortening in the T2 relaxation time component due to the bound water, i.e. some of the bound water is lost.