SURFACE GRAFTING OF A POLY(ORGANOPHOSPHAZENE) ONTO POLY(VINYL ALCOHOL) AND POLY(ETHYLENE-CO-VINYL ALCOHOL) USING TRIETHOXYSILANE AS A COUPLING AGENT

Triethoxysilane HSi(OEt)(3) was used a; coupling agent to graft a poly ( organophosphazene) (POPZ) containing allylic functions to the surfac e of poly(vinyl alcohol) or poly( ethylene- cc-vinyl alcohol) films. H ydrolyzed HSi(OEt)3, which contained both inorganic (Si-OH) and organi c (Si-H) reactivities, acted at the interface between the hydroxylated substrates (via a condensation reaction) and the allylic functions in POPZ (via a hydrosilylation reaction). Starting materials and graftin g surfaces were studied by ATR-IR and XPS spectroscopies and contact a ngle measurements. Data obtained indicated that different POPZ layers were produced, depending on whether the functionalization of materials with silane, and the grafting reaction were separately or simultaneou sly made. The POPZ layer thickness was higher when the grafting reacti on was preceded by the POPZ functionalization. In each cases, the modi fied surfaces showed marked increases in hydrophobicity character. (C) 1998 John Wiley & Sons, Inc.