Polymer Testing (Dec 2022)
Development of silver plated electrically conductive elastomers embedded with carbon black particles obtained from Kevlar waste source
Abstract
The stretchable conductive polymers were fabricated by adding conductive activated carbon fillers to the silicon elastomers and subsequently silver electroplating was performed. To solve the ecological and economical footprint issues the waste of Kevlar fibers were converted into activated carbon particles. The microstructure and porous activated carbon particles were prepared by chemical and physical activation process. The conductive elastomers were prepared into two steps. At first prepared carbon particles were mixed in polymeric silicon elastomer to make it conductive. Hence, the absorbance/adherence of carbon particles was confirmed into elastomer to develop the continuous network to facilitate the electrical conduction. Secondly, further electroplating of silver was performed to make the compact layer on carbon filled polymer. The surface morphology, element analysis and size of activated particles, carbon filled silicon elastomer and electroplated silicon elastomer was observed by SEM, EDX and Zeta size analysis. The FIR analysis was done to analyse the functional groups after the activation of Kevlar web before and after carbonization. Furthermore, the existence of carbon and silver was confirmed by XRD. The electrical resistivity and EMI shielding of elastomer samples was evaluated at different stages (after carbon filling, after silver plating, at stretching state and multiple stretching cycles). The minimum resistivity (12 Ω mm) and maximum EMI shielding (74 dB) was recorded at 0% stretch. While resistivity was increased up to 156 Ω mm at 60% stretch. Furthermore, the thermal stability of develop elastomeric sensors was checked through TGA and Ohmic heating process. At the end, the durability against moisture regain and mechanical action (tensile and hardness) was checked. The prepared elastomers can be used in number of applications including sensors (thermal, humidity control, insulation and electrical conduction). They can also be used as a flexible electrode adjusted with medical devices EMG, ECG and TENs machine.
