마그네타이트로 표면 개질된 질화붕소의 자기장 배향이 폴리우레탄 기반 유·무기 하이브리드의 열전도성에 미치는 영향

Abstract

The organic–inorganic hybrids of polyurethane (PU) and boron nitride (BN) modified with magnetite (Fe3O4) were prepared to investigate the effect of BN orientation under a magnetic field for enhancing the thermal conductivity of PU. The introduction of magnetite could be proved through scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). It was observed that the magnetite nanoparticles of 10− 100 nm covered the BN surface. The thermal conductivity of the hybrids showed an increasing trend as the BN content increased. The hybrid containing 60 wt% of BN modified with magnetite without magnetic orientation exhibited a thermal conductivity that was 3.8 times higher than that of the neat PU. However, the same hybrid with a magnetic orientation exhibited thermal conductivity that was 10 times higher than that of the neat PU. Conclusively, the effect of the magnetite BN orientation under the magnetic field on the thermal conductivity was found to be very effective by forming a thermal path of BN platelet along the magnetic field direction in the hybrids.