Synthesis & chemical and dielectric characterization of poly (linoleic acid)- g -poly (dimethylaminoethyl methacrylate): A novel high-κ graft copolymer

Abstract

In this study, poly (linoleic acid)-g-poly (dimethylaminoethyl methacrylate) (PLina-g-PDMA; PLDMA) graft copolymer was obtained from polymeric linoleic acid peroxide (PLina) possessing peroxide groups in the main chain by free radical polymerization of 2-dimethylaminoethyl methacrylate (DMA). Synthesized graft polymer, i.e. PLDMA, was first characterized chemically through proton nuclear magnetic resonance (1H NMR), differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA) and differential thermal analysis (DTA) and elemental analysis (EA) techniques. Later, PLDMA was injected into ITO coated glass cell and its electrical and dielectric measurements were carried at room temperature between 3 Hz and 3 MHz. PLDMA revealed dielectric constant (ε′) values on the order of 103 below 1 kHz. Therefore, having such high dielectric constant value, PLDMA was proposed as high-κ dielectric material with ε′ = 6141 at 3 Hz. Dielectric relaxation of the polymer was characterized using Cole-Cole plots. Investigation of electrical conductivity of PLDMA yielded dc conductivity as 36774 S/cm. Moreover, PLDMA was further dispersed with CdTe quantum dots to explore its utility for hybrid composites and effects of quantum dot dispersal on electrical and dielectric parameters were also investigated.