Study of dielectric properties of electron beam irradiated luffa fiber/PLA composites

The complex dielectric relaxation behavior of a biodegradable polymer composite is probed in the present investigation. The polymer composite was modeled using biodegradable polymer poly (lactic) acid (PLA) as matrix and natural fiber of Luffa cylindrica (LC) as reinforcement using microcompounding and injection molding. Aforetime the LC fibers used as reinforcement in PLA matrix, the LC fibers were exposed to 6 MeV electron beam of varying doses from 0.5 to 10.0 Gy generated from medical LINAC at room temperature 26 degrees C in presence of air. The modification in dielectric properties such as dielectric constant, dielectric loss factor, and ac conductivity was investigated in frequency range from 100 Hz to 1 MHz. The dielectric constant of virgin PLA increased from 61 to a maximum of 94 recording 52%increase when the electron beam-irradiated LC fiber is used as reinforcement in PLA matrix. The variation of dielectric constant and the dielectric loss factor in the frequency domain adhere to Debye model. However resonance peaks detected in the frequency spectrum of dielectric loss factor with the Cole-Cole variation substantiate the presence of multiple relaxations in the dielectric spectrum.