Functionalized Aluminum Nitride for Improving Hydrolysis Resistances of Highly Thermally Conductive Polysiloxane Composites
Mukun He, Lei Zhang, Kunpeng Ruan, Junliang Zhang, Haitian Zhang, Peng Lv, Yongqiang Guo, Xuetao Shi, Hua Guo, Jie Kong, Junwei Gu
Abstract
Abstract A series of divinylphenyl-acryloyl chloride copolymers (PDVB- co -PACl) is synthesized via atom transfer radical polymerization employing tert-butyl acrylate and divinylbenzene as monomers. PDVB- co -PACl is utilized to graft on the surface of spherical aluminum nitride (AlN) to prepare functionalized AlN (AlN@PDVB- co -PACl). Polymethylhydrosiloxane (PMHS) is then used as the matrix to prepare thermally conductive AlN@PDVB- co -PACl/PMHS composites with AlN@PDVB- co -PACl as fillers through blending and curing. The grafting of PDVB- co -PACl synchronously enhances the hydrolysis resistance of AlN and its interfacial compatibility with PMHS matrix. When the molecular weight of PDVB- co -PACl is 5100 g mol −1 and the grafting density is 0.8 wt%, the composites containing 75 wt% of AlN@PDVB- co -PACl exhibit the optimal comprehensive performance. The thermal conductivity ( λ ) of the composite is 1.14 W m −1 K −1 , which enhances by 20% and 420% compared to the λ of simply physically blended AlN/PMHS composite and pure PMHS, respectively. Meanwhile, AlN@PDVB- co -PACl/PMHS composites display remarkable hydrothermal aging resistance by retaining 99.1% of its λ after soaking in 90 °C deionized water for 80 h, whereas the λ of the blended AlN/PMHS composites decreases sharply to 93.7%.