Improvement of out-of-plane thermal conductivity of composite laminate by electrostatic flocking

Abstract

Increasing the out-of-plane thermal conductivity of polymer composite laminate is a challenge for applications that require heat dissipation. This paper adopted the electrostatic flocking method to embed different fillers in thin carbon fiber mat to produce a high thermal conductive ply, which was named fuzzy mat. The fuzzy mat was laminated alternatively with two-dimensional fabric to bridge the adjacent fabric plies. The effects of microstructure and structural parameters of fuzzy mat, as well as the filler type, on out-of-plane thermal conductivity were investigated. The results showed that the fuzzy mat effectively filled the resin rich area in the carbon fabric composite and greatly improved thermal conductivity. Pre-cured and double surface implanted fuzzy mat was beneficial for the construction of thermal conduction path. The out-of-plane thermal conductivities of the composite laminates increased as the content and length of pitch-based carbon fiber fillers increased. The thermal conductivity of composite laminate by introducing 10wt% fuzzy mat with 300- to 400-μm-long pitch-based carbon fiber filler was up to 1.2W/(m·K), which was 216% higher than the thermal conductivity of the control sample, which was 0.38W/(m·K). Moreover, the vapor-grown carbon fiber effectively improved both the out-of-plane thermal conductivity and the interlaminar shear strength.