[Composites Science and Technology] In-situ fabrication of hetero-structured fillers to significantly enhance thermal conductivities of silicone rubber composite films
writer：Kunpeng Ruan#, Han Yan#, Sijie Zhang, Xuetao Shi*, Yongqiang Guo and Junwei Gu*
keywords：Polymer-matrix composites
source：期刊
specific source：Composites Science and Technology
Issue time：2021年
With the method of precipitation followed by high temperature calcination, hetero-structured fillers boron nitride nanosheets@alumina (BNNS@Al2O3) were in-situ fabricated. Thereafter, thermally conductive & insulating BNNS@Al2O3/silicone rubber (SR) composite films were then prepared. The “point-surface” hetero-structured fillers BNNS@Al2O3 had more significant thermal conductivity coefficient (λ) improvement than single Al2O3, BNNS and directly blending BNNS/Al2O3 fillers. With the mass fraction of BNNS@Al2O3 to be 30 wt% (BNNS/Al2O3, 1:1, wt:wt), the in-plane λ (λ∥) and through-plane λ (λ⊥) of the BNNS@Al2O3/SR composite films attained 2.78 W/mK and 0.84 W/mK, 1.75 times higher than λ∥ (1.01 W/mK) and 3.0 times higher than λ⊥ (0.21 W/mK) of pure SR, also more excellent than BNNS/SR (λ∥=2.46 W/mK, λ⊥=0.76 W/mK), Al2O3/SR (λ∥=1.58 W/mK, λ⊥=0.50 W/mK) and directly blending (BNNS/Al2O3)/SR (λ∥=2.04 W/mK, λ⊥=0.62 W/mK) composite films under the same mass fraction of fillers. Also, BNNS@Al2O3/SR composite films presented wonderful mechanical, insulation as well as thermal properties.
采用“沉淀-高溫煅燒”法原位制備了具有“點-面”異質結構的氮化硼納米片@氧化鋁（BNNS@Al2O3）導熱填料，進而制備了BNNS@Al2O3/硅橡膠（SR）導熱絕緣復合膜。“點-面”異質結構導熱填料BNNS@Al2O3具有較單一Al2O3、BNNS和BNNS/Al2O3簡單共混填料更顯著的導熱系數（λ）提升效果。當BNNS@Al2O3用量為30 wt%（BNNS/Al2O3，1：1，wt：wt）時，BNNS@Al2O3/SR復合膜的面內λ（λ∥）和面間λ（λ⊥）分別達到2.78 W/mK和0.84 W/mK，較純SR的λ∥（1.01 W/mK）和λ⊥（0.21 W/mK）高出1.75倍和3.0倍，且優于相同填料用量下的BNNS/SR（λ∥=2.46 W/mK，λ⊥=0.76 W/mK）、Al2O3/SR（λ∥=1.58 W/mK，λ⊥=0.50 W/mK）和（BNNS/Al2O3）/SR（BNNS/Al2O3簡單共混，1：1，wt：wt，λ∥=2.04 W/mK，λ⊥=0.62 W/mK）復合膜。此外，BNNS@Al2O3/SR復合膜還兼具良好的力學性能、電絕緣性能和熱性能。