Radiation-induced grafting of styrene into poly(vinylidene fluoride) film by simultaneous method with two different solvents

Radiation-induced grafting of styrene into poly(vinylidene fluoride) (PVDF) films with 0.125 mm thickness at doses of 1 and 2.5 kGy in the presence of a styrene/N,N-dimethylformamide (DMF) solution (1:1, v/v) and at doses of 20, 40 and 80 kGy in presence of a styrene/toluene solution (1:1, v/v) at dose rate of 5 kGy h−1 was carried out by the simultaneous method under nitrogen atmosphere and room temperature, using gamma rays from a Co-60. The films were characterized before and after modification by calculated grafting yield (GY %), infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and thermogravimetry (TG/DTG). GY results shows that grafting increases with dose, and the grafting of styrene was confirm by FT-IR due to the new characteristic peaks and by the TG and DSC attributed to changes in thermal behavior of the grafted material. Results showed that the system allows the controlled grafting of styrene into PVDF using gamma rays at doses as low as 1 kGy in DMF.

► Different solvent leads to different grafting morphology.
► Solvent behavior under irradiation can affect the grafting reaction.
► Solubility is an important property in the simultaneous method.
► DMF allows to use small doses and to achieve higher grafting yields than toluene.