Study on photodegradation of injection-moulded β-polypropylenes

The effects of UV irradiation on β-nucleated injection-moulded polypropylenes (β-iPP) have been studied at several structural levels. Commercially available isotactic polypropylene was modified by 0.03 wt.% β-nucleating agent based on N,N′-dicyclohexylnaphthalene-2,6-dicarboxamide. β-iPP specimens were injection-moulded using a processing set-up in which only mould temperature was varied. It was found that specimens consisted of a skin-core structure, which was strongly influenced by varying mould temperatures. The structural development consequently affected the specimen degradability as shown by wide-angle X-ray scattering, light microscopy and micro-infrared microscopy.