Synthesis of novel ultraviolet stabilizers based on [60]fullerene and their effects on photo-oxidative degradation of polystyrene
Two N-benzyl fulleropyrrolidines were synthesized via Prato reaction. The polystyrene (PS) films containing 0.5 wt% fullerene and N-benzyl fulleropyrrolidines were prepared from toluene via the solvent evaporation method. The photo-oxidative activities and thermostability of these films were determined by monitoring the average molecular weight and thermogravimetric curve. The changes in weight loss (%) and tensile strength with irradiation time were also tracked. After 480 h of illumination, the weight loss of PS films was 6.8%, while the corresponding index of PS with C60 was 6.1%. The weight loss of PS with two fulleropyrrolidines was significantly lower than that before (3.8% and 2.7%). The results manifested the good ultraviolet (UV) stabilizing effect and thermostability of these complex films compared with PS. A probable mechanism was proposed to account for the stabilizing action of the [60]fullerene derivatives as multifunctional UV stabilizers.
