Enhanced thermal conductivity of polyvinyl alcohol insulation composites with m-BN@CNW hybrid materials

Abstract

In this paper, chitin was used as raw material to prepare chitin nanowhisker (CNW) by hydrochloric acid hydrolysis. Two hybrid materials, BNSi@CNW and BNPVP@CNW, were prepared by combining modified boron nitride (m-BN) with CNW, in which m-BN was modified with silane coupling agent (APTES) and polyvinylpyrrolidone (PVP) respectively. Polyvinyl alcohol (PVA) and hybrid materials were compounded to prepare PVA composites, respectively, meanwhile the structure and the thermal conductivity of PVA composites were systematically studied. The results show that BNSi@CNW and BNPVP@CNW are evenly dispersed in PVA due to the improved compatibility to enhance the thermal conductivity of PVA composites. The PVA/BNPVP@CNW is further modified by adding hydroxylated carbon nanotubes (CNT) to construct a plane-space thermal conductivity network, further improving the thermal conductivity of composite. Compared with neat-PVA, the thermal conductivity of the PVA composite is increased by 251.6%, and the stable electrical insulation performance is maintained.