Wang Jin-Biao, Sun Xin, Wang Yang, Cui Lu, Li Weili, Zhao Zheng-Bai
School of Materials Science and Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, China.
School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China.
J Colloid Interface Sci. 2025 Dec 15;700(Pt 1):138367. doi: 10.1016/j.jcis.2025.138367. Epub 2025 Jul 7.
Thermal interface material (TIM) is a widely used composite adhesive film whose adhesion and vertical thermal conductivity are critical to its application. Alumina (AlO) is now the most commonly used thermal filler in the industry, due to its high-cost performance. However, the spherical morphology of AlO particles poses a significant challenge for the straightforward development of anisotropic thermal conductivity structure within a polymer substrate. This study aims to design a single-layer AlO distribution structure to improve the vertical thermal conductivity of TIM. To accomplish this objective, a copolymer grafted with ethylene-vinyl acetate copolymer (EVA) and isobutylene-isoprene rubber (IIR) was synthesized via CC bonding. This EVA@IIR copolymer exhibits excellent self-repairing, adhesion, heat resistance and recyclability. Subsequently, the coating technology is employed to regulate the thickness of the adhesive film, thereby establishing a single-layer AlO distribution structure within the polymer substrate. Under the single-layer distribution structure, the particle size of AlO and the vertical plane (Z) thermal conductivity increase proportionally. At a 70 μm AlO loading of 70 wt%, the vertical thermal conductivity of the film increased by 129.3 % compared to the EVA@IIR substrate, and its thermal conductivity performance(Z) was superior to that of non-single-layer distribution structure films under the same loading. Therefore, this is conducive to effective heat transfer between heaters and heat sinks.
热界面材料（TIM）是一种广泛使用的复合胶膜，其粘附性和垂直热导率对其应用至关重要。氧化铝（AlO）因其高性价比，是目前行业中最常用的热填料。然而，AlO颗粒的球形形态对在聚合物基材内直接开发各向异性热导率结构构成了重大挑战。本研究旨在设计一种单层AlO分布结构，以提高TIM的垂直热导率。为实现这一目标，通过CC键合合成了一种接枝有乙烯-醋酸乙烯酯共聚物（EVA）和异丁烯-异戊二烯橡胶（IIR）的共聚物。这种EVA@IIR共聚物具有优异的自修复性、粘附性、耐热性和可回收性。随后，采用涂层技术调节胶膜厚度，从而在聚合物基材内建立单层AlO分布结构。在单层分布结构下，AlO的粒径与垂直平面（Z）热导率成比例增加。在AlO负载量为70 wt%、粒径为70μm时，与EVA@IIR基材相比，薄膜的垂直热导率提高了129.3%，并且在相同负载下其热导率性能（Z）优于非单层分布结构的薄膜。因此，这有利于加热器和散热器之间的有效热传递。
