Preparation and properties of modified spherical alumina/wrinkled graphene thermal conductive silicone rubber
Facing the 5G era,the thermal management of high-power and integrated equipment components has emerged as a key factor impacting performance.The rapid development of thermal management technology requires higher performances of thermal conductive interface materials including flexibility,insulativity,thermal conductivity and reliability.Taking spherical alumina(Al2O3)with varying particle sizes and two-dimensional graphene nanoplates(GNP)as thermal conductive fillers,they were modified to enhance their dispersion in silicone rubber matrices,strengthen interfacial bonding,and reduce interfacial thermal resis-tance.Then the modified spherical Al2O3/wrinkled GNP thermal conductive silicone rubber composite was prepared by a hot press-ing in-situ curing process to form an anisotropic GNP into a wrinkled structure using spherical Al2O3.The effect of content of thermal conductive fillers,as well as the thickness of the composite sample on the comprehensive performances of the composite were systematically investigated.The results indicate that the composite with 8 wt%GNP content and 50 wt%Al2O3 content reaches an in-plane thermal conductivity of 12.058 W/(m·K)and an out-of-plane thermal conductivity of 5.097 W/(m·K)when the compos-ite sample thickness is 0.8 mm.The thermal conductive silicone rubber composites have good flexibility,after adding GNP and Al2O3,the elongation at break are more than 120%,and the maximum is 171.68%.Moreover,the breakdown voltage of the compos-ite with 8 wt%GNP content and 50 wt%Al2O3 content reaches 3.5 kV,satisfying the insulation requirements when the composite sample thickness is 2 mm.Meanwhile it can also reaches an in-plane thermal conductivity of 1.979 W/(m·K)and an out-of-plane thermal conductivity of 1.231 W/(m·K).In comparison to the traditional silicone rubber sheet prepared by blending casting,this approach forms an interconnected thermal network to achieve high thermal conductive silicone rubber sheet which shows significant potential for applications in high-power electronic devices.
NETL
NSTL
万方数据
