Enhancing the thermal and mechanical properties of polyvinyl alcohol (PVA) with boron nitride nanosheets and cellulose nanocrystals

The rapidly increased thermal load as a result of the continuous down-scaling of electronic devices and increase in power densities requires faster and more effective heat dissipation. This work has been carried out to study the effect of inclusion of boron nitride nanosheets (BNNSs) and cellulose nanocrystals (CNCs) on the thermal and mechanical properties of a polyvinyl alcohol (PVA) matrix. Both BNNSs and CNCs improved the thermal conductivity, tensile strength and modulus of the polymer matrix at a low content (<1.6 wt%), however, the enhancement from the BNNSs is more significant. BNNSs also imparted significant UV blocking property to PVA films but the addition of CNCs reduced the UV protection ability of BNNS reinforced PVA films. In the visible light region, the hybridisation of CNCs increased the transparency of the BNNS reinforced PVA films that have potential use in transparent flexible electronic devices.