Novel polyacrylonitrile/potassium sodium niobate composites with superior dielectric and thermal properties

Abstract

Abstract Polyacrylonitrile (PAN) matrix composites dispersed with potassium sodium niobate (KNN) with volume fraction of 0–30% were prepared by ball milling followed by hot pressing. Density of composites followed the rule of mixture. Good dispersion of KNN particles in PAN matrix was confirmed using SEM. Composite containing 30 vol% KNN in PAN matrix recorded 342% increase in dielectric constant with a low dissipation factor of 0.18 w.r.t. neat PAN matrix. There was slight decrease in the dC resistivity of PAN/KNN composites with increase in KNN concentration but all the compositions showed the values of the order of 109 Ω–m, maintaining their insulating nature. Thermal stability of PAN was improved by incorporation of KNN with char yield at 800 °C going up from 24.8% to 60.9% and temperature for 10 wt% loss (T10) going up from 353 °C to 394 °C.