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Acrylonitrile (AN) has been grafted onto Polyvinylchloride (PVC) dissolved in Dimethylformamide (DMF) by means of gamma rays from a Co6' source. The grafting yield has been studied as a function of irradiation dose and initial AN/PVC ratio in the solution. The ratio PAN/PVC has been evaluated both in the grafted copolymer and its fractions by infrared spectroscopy. Ultrafiltrationmembranes have been prepared from the grafted PVC and its fractions,usingthe phase inversion technique. The UF performances have been studied as a function of PAN grafted % . The results show that both rejection water flux and increase with the grafting. Electron microscopy has also been employed to investigate the membrane structure.

The following conclusions can be drawn from our study: -Grafting of AN onto radiochemical methods gas). The PVC dissolved in DMF can be easily achieved by (that is by ganunairradiation in presence of grafted polymer so obtained can be separated and its inert fractioning shows the presence of two main constituents: the one mainly containing PVC and the other PAN, which are nevertheless compatible,in agreement with the findings elsewhere reported [20]. -UF membranes can be prepared from different PVC/AN grafted copolymers the usual "phase-inversion" technique. Such membranes show features (improved related to the permeate flux and rejection) which can compromise among the base be by interesting reasonably polymers characteristics. SEM observations confirm this hypothesis. From a practical point of view, the possibility of dry storage in spite of high PAN contents is particularly interesting. -Once more, has the radiochemical grafting carried out in a homogeneous solution proven effective in preparing new polymeric materials useful to preparation of UF membranes. Up to now,we mainly exploited this tool increase the hydrophilicity of hydrophobic polymers such as opposite can also be envisaged:to reduce ,at will, affinity of PVC, but the to the the extremely high water certain polymers which cannot be used for aqueous solutions UF because they would dissolve.