Silane Surface Treatment of Boron Nitride to Improve the Thermal Conductivity of Polyethylene Naphthalate Requiring High Temperature Molding

Thermal conductive composites were fabricated using a boron nitride (BN) filler and polyethylene naphthalate (PEN) matrix. To enhance the interfacial affinity, two types of silane curing agents, 3-aminopropyl triethoxysilane (APTES) and phenyl triethoxysilane (PTEOS), were introduced onto the BN particle surfaces. The modified BN particles were embedded in a PEN matrix via a melt mixing process using twin extrusion to form APTES@BN and PTEOS@BN composites. The highest thermal conductivity was exhibited at 50 wt% BN (1.41 W/mK), which increased to 1.54 W/mK and 1.63 W/mK when the BN particles were surface treated. These values were 9% and 16% higher than the thermal conductivities of the pure BN and the PEN matrix, respectively. The surface-treated composite also showed improved storage moduli and tensile strength because of the improved interfacial adhesion and the interaction between the BN filler and the PEN matrix. (C) 2017 Society of Plastics Engineers