Preparation and Characterization of UV-absorbing PVDF Membranes via Pre-irradiation Induced Graft Polymerization

Herein, excellent UV-absorbing poly(vinylidene fluoride) (PVDF) membranes were fabricated through the pre-irradiation induced graft polymerization method. The PVDF chains irradiated with 60 Co γ -ray were modified with the polymerizable UV absorber 2-[2-hydroxy-5-[2-(methacryloyloxy)ethyl]phenyl]-2 H -benzotriazole (RUVA-93). The influences of irradiation dose and monomer concentration on the prepared PVDF-g-PRUVA-93 membranes were investigated, and the optimal condition was eventually obtained. The chemical structures of the films were studied by 1 H-NMR, FTIR, and XRD. UV light transmittance and DSC tests were used to characterize the UV-absorbing performance and thermal property of the PVDF films before and after modification. The results proved that the PRUVA-93 side chains were successfully incorporated into the PVDF main chains and the obtained PVDF- g -PRUVA-93 films possessed remarkable UV-absorbing property. The modified membrane made under the optimized experiment condition could completely block the UV light in the range of 200−387 nm. Additionally, the transmittance of the PVDF- g -PRUVA-93 film could be reduced to 0.04% in 280−320 nm, where the light irradiation could damage polymer materials most seriously.