Enhanced thermal conductivity of poly(aryl ether nitrile ketone)/functionalized boron nitride composites by electrospinning–hot press technique

Abstract In this study, poly(aryl ether nitrile ketone)/functionalized boron nitride (PEK‐CN/f‐BN) composites fibers were prepared by solution blending followed by electrospinning technique. And the thermally conductive PEK‐CN/f‐BN nanocomposites were fabricated via hot press method. Octadecyltrimethylammonium Bromide (OTAB) was performed to functionalize the surface of boron nitride (BN) fillers, which were utilized as thermally conductive fillers to fabricate the corresponding PEK‐CN/BN composites. The thermal conductivity coefficient ( λ ) of the PEK‐CN/f‐BN composites (25 wt% f‐BN) was 0.702 W/mK, and the PEK‐CN/BN composites (25 wt% unfunctionalized BN) was 0.649 W/mK, whose λ is more than 200% higher than the λ of pure PEK‐CN (0.251 W/mK). Meantime, compared to the pure PEK‐CN, the glass‐transition temperature ( T g ) of the PEK‐CN/f‐BN composites was increased from 228.10 to 232.98°C, and the thermal stability of the PEK‐CN/f‐BN composites has been improved as well. It was also noticed that, under the ideal electrospinning conditions, when the content of BN and f‐BN attached to 25 wt%, the storage modulus ( E ′), loss modulus ( E ″), and dielectric loss tangent (tan δ ) values of the PEK‐CN/BN composites and PEK‐CN/f‐BN composites were higher than that of pure PEK‐CN.