Yongqiang Guo#, Lei Zhang#, Kunpeng Ruan, Yi Mu, Mukun He and Junwei Gu*. Enhancing hydrolysis resistance and thermal conductivity of aluminum nitride/polysiloxane composites via block copolymer-modification. Polymer, 2025, 323: 128189. 2023IF=4.1.（2區化學期刊）
https://doi.org/10.1016/j.polymer.2025.128189
Abstract
The preparation of thermally conductive silicone rubber composites incorporating aluminum nitride (AlN) as fillers has attracted considerable attention. However, the high susceptibility of AlN to hydrolysis and its limited compatibility with the silicone rubber matrix present significant challenges that hinder the enhancement of the composite''s thermal conductivity. In this work, AlN was modified through surface functionalization via grafting with divinylbenzene-acryloyl chloride block copolymer (PDVB-b-PACl), followed by compounding with poly(methylhydrosiloxane) (PMHS) to fabricate thermally conductive AlN@PDVB-b-PACl/PMHS composites. The modification significantly improved the hydrophobicity of AlN@PDVB-b-PACl, as demonstrated by a contact angle of 134.1° compared to 26.4° for unmodified AlN. When the molecular weight of PDVB-b-PACl is 5000 g/mol, the grafting amount is 0.8 wt%, and the loading of AlN@PDVB-b-PACl is 85 wt%, the AlN@PDVB-b-PACl/PMHS composite exhibited an optimal thermal conductivity of 1.82 W/(m·K), an 810% improvement over that of PMHS (0.20 W/(m·K)), and outperformed AlN/PMHS composites (1.58 W/(m·K)) with the same AlN loading. Additionally, the tensile strength of the composite was 0.58 MPa, approximately 2.4 times greater than that of PMHS (0.24 MPa).
以氮化鋁（AlN）為填料制備導熱硅橡膠復合材料近年來受到熱捧，但其極易水解且與硅橡膠基體的相容性差，不利于復合材料導熱性能的大幅提升。本文以二乙烯基苯-丙烯酰氯二嵌段共聚物（PDVB-b-PACl）對AlN進行表面功能化接枝改性（AlN@PDVB-b-PACl），再與聚甲基氫硅氧烷（PMHS）共混復合制備AlN@PDVB-b-PACl/PMHS導熱復合材料。AlN@PDVB-b-PACl的疏水性得到明顯提升，其與水的接觸角為134.1°，遠高于AlN與水的接觸角（26.4°）。當PDVB-b-PACl分子量為5000、接枝量為0.8 wt%，且AlN@PDVB-b-PACl的用量為85 wt%時，AlN@PDVB-b-PACl/PMHS復合材料兼具最優的導熱性能，其λ為1.82 W/(m·K)，較純PMHS的λ（0.20 W/(m·K)）提高了810%，也優于相同AlN用量的AlN/PMHS復合材料的λ（1.58 W/(m·K)）。其斷裂強度為0.58 MPa，約為純PMHS斷裂強度（0.24 MPa）的2.4倍。
論文亮點
1. 設計并合成了疏水且能提高AlN與PMHS界面相容性的二乙烯基苯-丙烯酰氯二嵌段共聚物（PDVB-b-PACl）。
2. 優化PDVB-b-PACl分子量為5000 g/mol時，AlN@PDVB-b-PACl/PMHS復合材料的界面熱阻最低。
3. 當AlN@PDVB-b-PACl的質量分數為85 wt%且其表面PDVB-b-PACl接枝量為0.8 wt%時，AlN@PDVB-b-PACl/PMHS復合材料的λ最高，為1.82 W/(m·K)，為純PMHS的λ（0.20 W/(m·K)）的9.1倍。
第一作者：郭永強、張磊
郵件地址：gyqnpu@nwpu.edu.cn、18695349879@163.com
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