Formation of Vinylidene in Polypropylene/Ethylene Vinyl Acetate (PP/EVA) Blends During Degradation

The effect of natural exposure and artificial weathering on selected properties of PP/EVA blends was investigated. The vinyl acetate concentration decreased with exposure time due to acetylation. The most pronounced effect of radiation is associated with oxidative degradation. The cross-linking of PP/EVA blends was attributed to the formation of vinylidene group. Weathering decreased the tensile strength, elongation at break, and Young's modulus of the naturally and artificially exposed blends. This reduction was the result of blends' molecular weight reduction due to the degradation induced by weathering.