With the continuous miniaturization of electronic devices, efficient heat dissipation becomes critical to avoid their performance deteriorates and structural damage. Graphene nanoplatelets (GnPs) with its exceptional electrical properties, nanometer dimensions and large aspect ratio, appear as an excellent fillers of polymer based nanocomposites. In this study, we developed an industrially viable technique for the fabrication of GNP- ultra high molecular weight polyethylene(UHMWPE) membrane with high thermal conductivity via multi-stage biaxial stretching. GNP/UHMWPE membrane were firstly obtained through melt mixing and then biaxial stretched above the melting point allowed by UHMWPE’s extremely broad rubbery plateau provided by numerous entanglements and long molecular chain. Afterwards, solid state biaxial stretch was preformed to further increase the crystallinity of UHMWPE and improve the orientation of GNP. The strain-induced crystallization, along with the nucleation effect and of GNP, are responsible for dramatically improvement of thermal conductivity through coordinate lattice movements. In addition, the construction of more perfect heat diffusion path results from elevation of biaxial orientation and dispersion of GNP. Thus, six times of higher values than pure UHMWPE have been achieved when only 5vol% GNP added through in-plane laser-flash thermal analysis. Therefore, this technique provides a novel approach to the development of a more effective heat conduction path with low filler content for new generations of miniaturized electronic devices.

Impact of multi-stage biaxial stretching on thermal conductivity of GNP/UHMWPE membrane

2019 Spring National Meeting

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