Effects of amphiphilic agent on thermal conductivity of boron nitride/poly(vinyl butyral) composites

Highlights: • The platelet BN particles were oriented in poly(vinyl butyral) (PVB) matrix by tape-casting process. • The degree of BN orientation was estimated from XRD patterns of BN/PVB composites. • Surface treatment of BN with amphiphilic agent was confirmed by FT-IR and elemental analysis. • The BN/PVB composites with in-plane oriented 8-μm-sized BN particles showed a higher thermal conductivity than the other composites. - Abstract: Dependence of thermal conductivity of boron nitride (BN)/poly(vinyl butyral) (PVB) composites on the orientation and particle size of BN with an amphiphilic agent was investigated. The platelet BN particles were oriented in the polymer matrix by physical processes such as tape-casting process. A comparison of the thermal conductivity of the specimens with that of pristine BN showed that the BN/PVB composite treated with amphiphilic agents such as C₁₄H₆O₈ and C₂₇H₂₇N₃O₂ showed a higher thermal conductivity than the PVB composite with pristine BN. It was also found that the thermal conductivity of the C₁₄H₆O₈-treated BN/PVB composite was higher than that of the C₂₇H₂₇N₃O₂-treated composite due to the good dispersion and interfacial adhesion with C₁₄H₆O₈. Also, the thermal conductivity of the composite with an in-plane orientation of 8-μm-sized BN was higher than that of the composites with different particles sizes because of the improvement in the high degree of orientation