Thermal Conductive Polymer Composites: Recent Progress and Applications

Abstract

As microelectronics technology advances towards miniaturization and higher integration, the imperative for developing high-performance thermal management materials has escalated. Thermal conductive polymer composites (TCPCs), which leverage the benefits of polymer matrices and the unique effects of nano-enhancers, are gaining focus as solutions to overheating due to their low density, ease of processing, and cost-effectiveness. However, these materials often face challenges such as thermal conductivities that are lower than expected, limiting their application in high-performance electronic devices. Despite these issues, TCPCs continue to demonstrate broad potential across various industrial sectors. This review comprehensively presents the progress in this field, detailing the mechanisms of thermal conductivity (TC) in these composites and discussing factors that influence thermal performance, such as the intrinsic properties of polymers, interfacial thermal resistance, and the thermal properties of fillers. Additionally, it categorizes and summarizes methods to enhance the TC of polymer composites. The review also highlights the applications of these materials in emerging areas such as flexible electronic devices, personal thermal management, and aerospace. Ultimately, by analyzing current challenges and opportunities, this review provides clear directions for future research and development.

Keywords: advanced application; polymer nanocomposites; thermal conductive.

Figure 1

(a) Illustration of molecular chains or atoms vibration by mass and spring system; (b) crystalline and amorphous regions in polymers; (c) factors causing phonon scattering in polymers [66].

Figure 2

(a) “Sea-island” in low fillers loading; (b) thermal conduction paths in high fillers loading; (c) percolation phenomenon; (d) thermoelastic coefficient theory [66].

Figure 3

Microscopic ordered structures and the corresponding phonon transport model of polyvinyl alcohol (PVA) composite films [86].

Figure 4

Enhancement mechanism through reinforced crosslinking and formation of thermal transport network by adding borax [100].

Figure 5

Schematic diagrams of heat transport in a pure polymer, a polymer composite filled with a traditional dispersed filler, and a composite filled with a 3D interconnected network of fillers [106].

Figure 6

(a) Illustration for Ti₃C₂T_x MXene prepared from Ti₃AlC₂ MAX precursor by HCl/LiF etching. (b) TEM image of MXene nanosheets (insets: electron diffraction pattern of MXene and SEM image of Ti₃AlC₂ MAX). (c) Illustration for PBO nanofibres prepared from commercial PBO fibres by MSA/TFA exfoliation. (d) TEM image of PBO nanofibres (inset: SEM image of PBO fibre). (e) Illustration for the nacre-inspired PBO/MXene films prepared by the sol-gel-film conversion approach including a proton-consumption homogeneous gelation process. (f–h) SEM images of (f) the freeze-dried PBO/MXene gel and (g,h) the cross-section of PBO/MXene film. (i) The optical photograph of PBO/MXene film [107].

Figure 7

(a) Schematic illustration of the electrocaloric polymer stack and solid-state cooling device. (b) Photograph of the active EC device; the elaborated main framework was obtained by 3-D printing. (c) The schematic shows how an electromagnetic field drives an electrocaloric polymer stack to move heat from a heat source to a heat sink. The high-speed heat transfers from heat source to sink can be achieved by associating the active cooling of electrocaloric polymer stack with the heat dissipation cycle. (d) The working mechanism of the ECE based on the change in dipole entropy. (e) Time domain illustration of the cooling cycle. (f) The maximum heat flux of the electrocaloric stack on the heating and cooling side versus the applied electric field is measured by a heat flux sensor at an operation frequency of 0.1 Hz. (g) Infrared thermal images of CPU in active electrocaloric cooling. (h) Temperature versus time curves of CPU in air, by active electrocaloric cooling (U1 = 12 V at 1 Hz, U2/d2 = E = 0 MV m⁻¹; d2 is the thickness of the electrocaloric cooling stack) and active electrocaloric cooling (U1 = 12 V at 1 Hz, E = 30 MV m⁻¹) [123].

Figure 8

(a) The flexibility of the composite. (b) In-plane thermal conductivity of the 100%-prestrained composite in response to 1000 bending cycles. (c) Surface temperature variations of the flexible PI heating film against time. (d) Temperature fluctuation of the flexible PI heating film with the 100%-prestrained composite under a bending angle of 0−150°. (e) Temperature fluctuation of the flexible PI heating film with different TIMs under more than 3000 bending cycles [131].

Figure 9

Rational design of solid-state polymer electrolyte with BN additive. (a) Illustration of solid-state Li-S batteries with polymer-based electrolytes and schematic comparison of heat transport through electrolytes with and without BN additives and (b) sketch of a composite electrolyte consisting of 2D BN flakes and a blended PEO-PVDF polymer with LiTFSI [140].

Figure 10

Thermal management application of PEG@TPU/BNNS-es film (with 32 wt% BNNSs content) in thermoelectric generator (TEG). (a) Schematic mechanism of TEG exposed to air (top) and (b) loaded with PEG@TPU/BNNS-es (PCN) (bottom). (c−e) Output current, output voltage and output power of TEGs with/without PCC at different heating temperature, respectively. (f) Temperature difference between the hot and cold sides versus heating temperature of TEGs. (g) Conception diagram of potential application of TEGs integrated with the PEG@TPU/BNNS-es film for outdoor activities [158].

Figure 11

Solar heat storage fabric. (a) Schematic illustration of fabric treatment and corresponding SEM images. The inset of SEM images shows real photographs of corresponding fabric. (b) DSC thermograms of raw fabric, PCM fabrics and PCM@resin fabric. (c) TGA thermograms of raw fabric, PCM fabrics and PCM@resin fabric. (d) IR images of raw fabric, PCM fabrics and PCM@resin fabric before and after 2 min of solar irradiation at 80 mW/cm². The PKU letter pattern is IR images of developed fabrics after 2 min of solar irradiation. (e) Bar graph showing fabric weight loss after washing [167].

Figure 12

(a) Experimental setup for the evaluation of heat storage/release of the F-FSPCMs module. (b) Surface temperature of the F-FSPCMs module during a heat storage/discharge cycle (7 mm thickness). (c) Temperature holding time of the F-FSPCMs module with the same heat supply for 3 mm, 5 mm and 7 mm thickness. (d) Several types of integrated and portable F-FSPCMs modules for personal thermotherapy. (e) Temperature evolution of insulating device based on F-FSPCMs module (5 mm thickness) acting on a knee during charging and discharging [177].