Hydrophobic modification of polymer surfaces via grafting to approach

Hydrophobic grafted polymer layers were permanently anchored from the melt onto poly(ethylene terephthalate) (PET) and nylon substrates modified with air plasma and poly(glycidyl methacrylate) (PGMA) anchoring layer. Polypentafluorostyrene (PPFS) of different molecular weights with an end carboxyl group was used for the grafting. Atomic force microscopy imaging revealed that, in general, the grafted chains evenly covered all substrates. Thickness of the grafted layer increased with temperature and time of grafting. To reach a significant level of grafting and consequently high hydrophobicity temperature above 140 degrees C, 5 min of grafting had to be used. For longer grafting time (I h) the hydrophobicity could be reached at 120 degrees C. The thickness of the grafted layer should be at least 2-3 nm to attain the high water-contact angle. The polymer grafting technique developed could be readily applied to surface modification of fibers and textiles leading to generation of hydrophobic fibrous materials.