Sustainable, Alternative Conductive Fillers for Flexible Electronics: Investigation of Filler Size on Morphological and Electrical Properties of Styrene-[Ethylene-(Ethylene-Propylene)]-Styrene Block Copolymer (SEEPS) Composites

Sustainability is getting popular for many engineering applications from packaging to textiles, energy to electronics. Since renewable, environmental friendly sources lowers the negative impacts of the end product on ecology, sustainability studies generally start with the raw materials. The sustainability of electronic materials has gained importance because of limited amount of resources and increasing costs as well as environmental restrictions. In this study, pistachio shell waste was used to synthesize conductive fillers for the fabrication of sustainable flexible electronics. Pistachio shell waste was carbonized. After carbonization, two different grounding settings were used to obtain different filler sizes. In order to compare the effects of filler size on electrical and morphological properties of the composites, six different samples were prepared based on filler concentration with styrene-[ethylene-(ethylene-propylene)]-styrene block copolymer. Homogeneous filler distribution and good filler-matrix interface were observed for both composite sets. Filler size was found significant in terms of the electrical conductivity of the composites. For larger fillers, the percolation region was found to shift to lower concentration compared to smaller filler size.