The effect of UV irradiation on the dielectric properties of bionanocomposites with fillers of biological origin and metal nanoparticles

Abstract

In this paper, information is given about the investigation of the dielectric properties of bionanocomposites modified with fish bones (FBs) and scales and metal nanoparticles (Al, Fe) with 50–80 nm dimension before and after ultraviolet (UV) irradiation, depending on the temperature, the irradiation time and the volume content of fillers. The investigations of dielectric permittivity and dielectric loss were carried out in the temperature range 300–390 K, the time of irradiation with UV rays were 50, 100, 70 and 150 h, and the filler contents were 3, 5, 7, 10, 15 vol.% and nanoparticles 1 vol.% Al (Fe). It was found that the dielectric constant of UV-irradiated biocomposites with FB additives increases and the dielectric loss decreases. An increase in dielectric constant is also observed with an increase in the volume content of a biological origin filler. Note that the effect of UV irradiation causes the appearance of a new region of dielectric loss in the temperature-dependent tan[Formula: see text] of the polyethylene. However, in modified samples after irradiation, under the same conditions, the change in dielectric properties is much less pronounced than in the initial ones, i.e. the dielectric constant increases monotonically, and the value of tan[Formula: see text] in the maximum of the new loss region is much smaller. Moreover, the effect of the additive is manifested in slowing down the process of LDPE oxidation in the irradiation zone, since the main losses of the polyethylene are primarily caused by the relaxation of the carbonyl groups. Thus, the observed dependences of [Formula: see text] and tan[Formula: see text] on the time of exposure to UV rays are explained by a change in the physical structure of the polymer matrix and the boundary layer of the components composition under the action of charges formed during irradiation.