Nushaba Gadirova In pure polypropylene, an absorption peak around 260 nm is uncommon and may indicate the presence of additives or oxidative degradation products, as pure PP typically absorbs below 220 nm due to σ → σ* transitions.

From what I know, additive-free polypropylene has essentially no chromophores in the near-UV above ≈220 nm, so you normally see its π→σ* and σ→σ* backbone absorptions only below 250 nm. An absorption band around 260 nm in a “pure” PP sample almost always means there’s something in the resin that does absorb there, possibly phenolic antioxidants or some oxydative byproducts Article Effect of Alteration of Antioxidant by UV Treatment on the D...

Alvena Shahid Thank you for your answer.Could this be due to an incorrect mode selected during the UV measurement, or could it be related to the polymer film preparation process?