Thermally conductive poly(ether ether ketone)/boron nitride composites with low coefficient of thermal expansion

Abstract

The substantial heat generation due to miniaturization and high-degree integration of electronic devices is one of the major issues to facilitate efficient thermal management in power electronics. Though epoxy-based composites have shown great interest in different applications such as laminated circuit board, electronic component encapsulations, and potting, they have low application temperature (up to 150 °C) and higher mismatch of coefficient of thermal expansion (CTE) between the heat source and heat sink. Here, poly(ether ether ketone) (PEEK) composites reinforced with hexagonal boron nitride (hBN) nanoplatelets have been developed by liquid mixing and re-melting method for a step change in composite materials with lower CTE and significantly improved thermal dissipation capability. The lowest achieved CTE is 2.1 µm m−1 K−1, and the highest thermal conductivity is 1.04 W m−1 K−1 in PEEK/hBN composites at 30 wt% hybrid hBN content (hBN platelets with two different sizes, i.e. 70 nm and 500 nm, taken as 1:1 weight ratio), due to the formation of thermally conductive inter-filler networks. The composites show negligible variation in K with the working temperature up to 250 °C. The developed composites also exhibit excellent electrical insulation properties; thus, they will have good potential in thermal management for power electronic applications. Graphical abstract

A rational study on the hydrothermal aging of AFP manufactured CF/polyetherketoneketone composites with in situ consolidation supported by acoustic emission inspection

“…The peaks at 838, 778, 744, and 693 cm −1 indicate the presence of C‐H groups 27 . CH bending vibration absorption peaks outside the benzene ring plane arise at 838 and 778 cm −1 28,29 . The peak at 3066 cm −1 is attributed to the stretching vibrations of the hydroxyl group (OH), and the peaks at 2920 and 2850 cm −1 are associated with the aliphatic polyether (ROR) 2 .…”

“…27 C H bending vibration absorption peaks outside the benzene ring plane arise at 838 and 778 cm À1 . 28,29 The peak at 3066 cm À1 is attributed to the stretching vibrations of the hydroxyl group ( OH), and the peaks at 2920 and 2850 cm À1 are associated with the aliphatic polyether (R O R). 2 The spectrum of the AA CF/PEKK samples reveals the same characteristic bands as the BA CF/PEKK sample but with the reduced peak intensities.…”

An experimental implication of long‐term hot‐wet‐aged carbon fiber/polyether ketone ketone composites: The impact of automated fiber placement process parameters and process‐induced defects

“…C–H groups are present in the peaks at 838, 743, and 693 cm −1 48 . C–H bending vibration peaks outside the plane of the benzene ring are observed at 838 and 743 cm −1 49,50 . The peak proves hydroxyl group (–OH) presence at 3307 cm −1 22 …”

“…48 C-H bending vibration peaks outside the plane of the benzene ring are observed at 838 and 743 cm À1 . 49,50 The peak proves hydroxyl group (-OH) presence at 3307 cm À1 . 22 The appearance of characteristic peaks of the PEKK molecule before and after aging without any new peaks or peak shifts indicates that the hydrothermal aging process causes no chemical change in CF/PEKK composites (Figure 11).…”

Analysis of the Structure and the Thermal Conductivity of Semi-Crystalline Polyetheretherketone/Boron Nitride Sheet Composites Using All-Atom Molecular Dynamics Simulation

“…A boron nitride (BN) sheet has been used as a filler in polymer composites for various applications, including aerospace, electronic devices, and semiconductors, because it leads to excellent mechanical properties and high thermal transport performance [ 17 , 18 ]. In a report by Ghosh et al [ 19 ], the thermal conductivity of PEEK increased after the addition of hexagonal boron nitride (h-BN). The thermal conductivities of polymer composites reinforced with BN sheets were higher than those of untreated polymers due to the effect of not only the high thermal conductivities of the fillers, but also the increase of phonon velocities between the polymer chains and fillers [ 20 ].…”