Structure evolution in α- and β-polypropylenes under UV irradiation

Abstract

Commercially available isotactic polypropylene (PP) was modified by a specific β-nucleating agent based on N,N'-dicyclohexylnaphthalene-2,6- dicarboxamide. From both neat (α-iPP) and nucleated (β-iPP) polypropylenes compression-moulded plates were prepared using various processing conditions, and then exposed to UV-irradiation. Molecular degradation and the evolution of supermolecular structure were determined using infrared and UV spectroscopy, wide-angle X-ray scattering and differential scanning calorimetry. Different impact of UV irradiation on both α-iPP and β-iPP is presented. Furthermore, the effect of processing conditions on photodegradability is proved.