The invention concerns a radiopaque, non-biodegradable, water-insoluble iodinated benzyl ether of poly(vinyl alcohol) consisting of a PVA having covalently grafted thereon iodinated benzyl groups comprising 1-4 iodine atoms per benzyl group, a process for preparing the same comprising reacting a 0-100% hydrolyzed PVA with a iodinated benzyl derivative comprising 1-4 iodine atoms per benzyl group in a polar aprotic solvent in the presence of a base in anhydrous conditions. Said iodo-benzylether-PVA is particularly useful as embolic agent in an injectable embolizing composition. The invention also concerns an injectable embolizing composition comprising said iodo-benzylether-PVA and capable of forming a cohesive mass upon contact with a body fluid by precipitation of the iodo-benzylether-PVA. Said injectable embolizing composition is particularly useful for forming in-situ a cohesive mass in a blood vessel or into a tumor. The invention further concerns a coating composition containing said iodo-benzylether-PVA and capable of forming a radiopaque coating on a medical device. The invention further concerns particles formed of said iodo-benzylether-PVA.
