TRANSPORT OF SMALL MOLECULES IN POLYOLEFINS .1. DIFFUSION OF IRGANOX 1010 IN POLYETHYLENE

Transport properties of antioxidants in polymers have a very important role in their effectiveness. Lifetime of a product is strongly influenced by the physical loss of the stabilizer. The diffusion coefficient (D) and solubility (S) of Irganox 1010 in low-density polyethylene (LDPE) were studied at 45 and 80-degrees-C, changing the physical state of the antioxidant in the additive source. Irganox 1010 is a polymorphous material; its actual morphology depends on the thermal history. It was proved that the morphology of the additive has a determining effect on the measured D and S values. Contradictions in the literature data can be explained by the differences in the experimental conditions, i.e., in the physical state of the penetrant in the additive source and the crystallinity and orientation of the polymer.