Thermal behavior and dielectric response of epoxy–boron nitride composites reinforced with short human hair fiber

Abstract

AbstractPolymer composites with low dielectric constant and high thermal conductivity are gaining considerable attention due to their rising demand in various microelectronic applications such as printed circuit boards, connectors, encapsulations, and electrical contacts. In the present investigation, thermal and dielectric properties of a new class of epoxy‐based hybridized composites with improved thermal conductivity (k), high glass transition temperature (Tg), low coefficient of thermal expansion (CTE), controlled dielectric constant (Dk), and low dielectric loss (DL) have been reported. Epoxy‐based composites are fabricated by solution casting method with various wt% (0, 5, 10, 15, and 20 wt%) of short hair fiber and with a fixed proportion of micro‐sized boron nitride (BN) (10 wt%) particles. Effects of fiber content on different thermal properties of the composites such as effective thermal conductivity (k), CTE, and Tg are studied by conducting tests as per appropriate American Society for Testing and Materials (ASTM) standards. Dielectric properties of the composite samples such as dielectric constant (Dk) and dielectric loss (DL) are evaluated in a HIOKI‐3532‐50 Hi Tester Elsier Analyzer. It is observed that with the addition of BN, thermal conductivity of the hybrid composite has significantly improved whereas the dielectric constant of the composite shows a decreasing trend with the increase in fiber content and operating frequency. There is also a marked improvement in the glass transition temperature of epoxy with the incorporation of short human hair fibers.