Tuning of polypropylene wettability by plasma and polyhedral oligomeric silsesquioxane modifications

In this work, we have exposed polypropylene (PP) to plasma treatment and then reactively coated with polyhedral oligomeric silsesquioxane-isothiocyanate (POSS-NCS) in order to modify both of its surface characteristics: chemical composition and roughness. The results of scanning electron microscopy (SEM), atomic force microscopy (AFM), and attenuated total reflectance-Fourier transform infrared spectroscopy (ATR-FTIR) showed a strong relation between plasma exposure time and PP roughness, as expected. On the other hand, the POSS-coating promoted the reduction of surface roughness, but induced a substantial increase in the water contact angle (WCA), probably due to the modification of the surface chemical nature. Besides, the surface tuning method discussed here is a fast, industrial-suitable procedure which can be applied to different polymers.