POLYPHOSPHAZENES AS BIOMATERIALS - SURFACE MODIFICATION OF POLY(BIS(TRIFLUOROETHOXY)PHOSPHAZENE) WITH POLYETHYLENE GLYCOLS

Investigations were carried out on the metathetical exchange reaction between the -O-CH2CF3 moieties of poly(bis(trifluoroethoxy)phosphazene ) (PTFP), in the state of slightly swollen films, and the alkoxide ion s derived from methoxypolyethylene glycol (MPEG) of molecular mass ran ging from 350 to 5000 g/mol. The substitution of these hydrophilic cha ins, mostly confined to thin surface layers, was revealed by means of optical microscopy and scanning electron microscopy observations, surf ace elemental analysis by energy-dispersive X-ray analysis (EDXA), FTI R-ATR analysis and water contact angle measurements. The surface bioco mpatibility was enhanced in all cases, whilst the mechanical propertie s of the original PTFP films were substantially retained in the modifi ed samples exhibiting low substitutions. Such samples were obtained es pecially when the metathetical reaction was carried out with MPEG5000.