Surface modification of polypropylene. I. Surface enrichment of poly(ethylene glycol) on polypropylene/poly(ethylene glycol) blends

The enrichment of poly(ethylene glycol) (PEG) on the surface of poly(ethylene glycol)/polypropylene (PEG/PP) blends was investigated by using attenuated total reflection infrared spectroscopy (ATR-FTIR), contact angle measurement (CDA), and scanning electron microscopy (SEM). The preferred aggregation of the PEG component on the film surface of PP/PEG blends was affected mainly by the content, the molecular weight, and the segregated domains of PEG. Lower content and dies with higher surface energy favored the surface enrichment of PEG. The PEG with higher molecular weights was distributed in PP with larger phase domains, which resulted in a lower tendency toward preferred aggregation and surface enrichment.