Surface Modification of Poly(vinyl alcohol) by Peroxide-Initiated Grafting of a Poly(organophosphazene)

A poly(organophosphazene) bearing allylic functions (POPZ (1)) has been grafted onto the surface of a poly(vinyl alcohol) (PVA) film with the aid of the benzoyl peroxide initiator. The PVA films were first coated with toluenic solutions of POPZ and peroxide and then heated. After grafting, they were extracted with toluene to remove ungrafted POPZ. The resultant surfaces were characterized by ATR-IR, UV, XPS spectroscopies, X-ray fluorescence spectrometry, and gravimetric and contact angle measurements. The presence of the covalently bonded and cross-linked POPZ on the PVA surface gives it hydrophobic character, which may be helpful in improving the oxygen-barrier properties at high humidity.