The influence of consolidation and artificial weathering on all-PP composite behavior

The purpose of this work was to evaluate the effect of consolidation parameters on the mechanical properties of all-polypropylene composites. Consolidation time does not induce any significant influence, whereas processing temperature and in particular coextruded tape characteristics deeply affect laminate performance. The DSC analysis demonstrated that the proximity of copolymer and homopolymer melting points results in a reduction in the operating window. This suggests the implementation of a more effective temperature control during thermoforming to avoid reinforcement relaxation and localized melting. Artificial weathering was conducted under noon summer light condition to assess the effect of ultraviolet exposure on laminates. After 100 and 250 h, sample performance drops significantly, with overall strength and elongation reduction up to 70 and 88%, respectively. Low molecular weight by-products were identified using Raman spectroscopy on specimens surface, confirming the mechanical property decrement due to photo-oxidation process.