Grafting of styrene in polyvinylidene fluoride by high energy ion irradiation

Polyvinylidene fluoride (PVDF) foils were irradiated in air with 56 MeV lithium ions at different fluences (10(10)-2 x 10(11) ions/cm(2)). After irradiations, the samples were placed in a test tube containing liquid styrene monomer and immersed in a controlled temperature oil-bath at 60 degrees C (20 h) to graft polystyrene chains in the PVDF matrix. Differential scanning calorimetry and X-ray diffraction techniques were used to get informations about the grafting yields and the structural changes of the semicrystalline PVDF matrix. Links between polystyrene chains and PVDF matrix were evidenced both by the appearance of a glass transition in the calorimetric curves of the grafted samples as well as by the reduction of PVDF crystallinity with increasing the grafting yield. All the experimental results suggest that copolymerization is a bulk process occurring along the ion track.