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区化学期刊）

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).

以氮化铝（AlN）为填料制备导热硅橡胶复合材料近年来受到热捧，但其极易水解且与硅橡胶基体的相容性差，不利于复合材料导热性能的大幅提升。本文以二乙烯基苯-丙烯酰氯二嵌段共聚物（PDVB-b-PACl）对AlN进行表面功能化接枝改性（AlN@PDVB-b-PACl），再与聚甲基氢硅氧烷（PMHS）共混复合制备AlN@PDVB-b-PACl/PMHS导热复合材料。AlN@PDVB-b-PACl的疏水性得到明显提升，其与水的接触角为134.1°，远高于AlN与水的接触角（26.4°）。当PDVB-b-PACl分子量为5000、接枝量为0.8 wt%，且AlN@PDVB-b-PACl的用量为85 wt%时，AlN@PDVB-b-PACl/PMHS复合材料兼具最优的导热性能，其λ为1.82 W/(m·K)，较纯PMHS的λ（0.20 W/(m·K)）提高了810%，也优于相同AlN用量的AlN/PMHS复合材料的λ（1.58 W/(m·K)）。其断裂强度为0.58 MPa，约为纯PMHS断裂强度（0.24 MPa）的2.4倍。

论文亮点

1. 设计并合成了疏水且能提高AlN与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. 优化PDVB-b-PACl分子量为5000 g/mol时，AlN@PDVB-b-PACl/PMHS复合材料的界面热阻最低。

3. 当AlN@PDVB-b-PACl的质量分数为85 wt%且其表面PDVB-b-PACl接枝量为0.8 wt%时，AlN@PDVB-b-PACl/PMHS复合材料的λ最高，为1.82 W/(m·K)，为纯PMHS的λ（0.20 W/(m·K)）的9.1倍。

第一作者：郭永强、张磊

邮件地址：gyqnpu@nwpu.edu.cn、18695349879@163.com

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