Abstract：PPTA is a high-insulation, high-modulus fiber material that is widely utilized in the insulation protection of power equipment. However, its inherently low thermal conductivity limits the ability to dissipate heat effectively. Recently, nano-doping modification and coupling agent grafting have emerged as effective methods for enhancing the thermal properties of high polymers. BN is an inorganic filler with favorable thermodynamic properties while there is limited research on BN modified with coupling agents doped PPTA. To investigate the impact of BN fillers modified with different silane coupling agents on the thermomechanical properties of aramid composites, four types of silane coupling agents (KH550, KH560, KH580, and QX1324) were selected, various modified BN composite models were created by doping para-aramid (PPTA) using Materials Studio. The thermal conductivity, glass transition temperature, mechanical properties, and intermolecular interactions of the composite models were analyzed by the molecular dynamics method. Firstly, the thermal conductivity of the composite system was calculated using the rNEMD method. The thermal conductivity of the composite systems modified with coupling agents were significantly enhanced. Specifically, the thermal conductivity of BN-KH560/PPTA and BN-QX1324/PPTA increased by 83.05% and 74.58%, respectively, compared with pure PPTA. RDF analysis indicated that the interaction between the end group of KH560 and QX1324 coupling agents and PPTA was more pronounced. Additionally, the glass transition temperature of the composite system was analyzed by the specific volume-temperature method, the BN-QX1324/PPTA system reached 597.746 K, which represented a 12.93% increase. Regarding mechanical properties, the Young's modulus and shear modulus of the composite systems were consistently higher than those of pure PPTA over the temperature range from 300 K to 700 K. At 300 K, the Young's modulus of the BN/PPTA, BN-KH550/PPTA, BN-KH560/PPTA, BN-KH580/PPTA, and BN-QX1324/PPTA systems was, on average, 9.95% higher compared to PPTA. Furthermore, the BN-QX1324/PPTA system demonstrated greater resistance to the degradation of mechanical properties at high temperature. Regarding structural parameters, the reasons for the improved performance of the composite systems were elucidated through calculations of cohesive energy density, free volume fraction, hydrogen bond number, and other parameters that assessed intermolecular interactions. Modified BN enhanced the cohesive energy density of the systems through hydrogen bonding and van der Waals force, further strengthening the interaction within the composite systems. Notably, due to the strong electronegativity of fluorine groups, the cohesive energy density of the BN-QX1324/PPTA system increased the most, with an average rise of 13.32%. Additionally, it exhibited strong resistance to external electric field interference. To verify the validity of the calculation results, the BN-QX1324/PPTA system, which showed the best modification effects in the simulation, was selected for experimental investigation. The results indicated that the thermal conductivity, glass transition temperature, Young's modulus, and breakdown field strength of the PPTA/BN-F system were significantly improved that compared to the pre-modification values, and the trends were consistent with the simulation results. This study validates the reliability of the simulation calculations and show that the enhanced intermolecular interactions between the fluorinated group and PPTA in the QX1324 coupling agent are the underlying reasons for the observed performance improvements.
[1] 谢春杰, 何然, 庹新林, 等. 对位芳纶气凝胶粉体的制备与性能研究[J]. 化工学报, 2021, 72(12): 6361-6370. Xie Chunjie, He Ran, Tuo Xinlin, et al.Preparation and performance of para-aramid aerogel powders[J]. CIESC Journal, 2021, 72(12): 6361-6370. [2] 张文琦, 范晓舟, 李宇轩, 等. 基于分子动力学的芳纶/功能化碳纳米管复合材料体系热力学性能模拟[J]. 电工技术学报, 2024, 39(5): 1510-1523. Zhang Wenqi, Fan Xiaozhou, Li Yuxuan, et al.Simulation of thermodynamic properties of aramid/ functionalized carbon nanotubes composites based on molecular dynamics[J]. Transactions of China Electro-technical Society, 2024, 39(5): 1510-1523. [3] 陈磊, 宋欢, 李正胜, 等. 芳纶纤维材料在电气绝缘和电子领域中的应用进展[J]. 绝缘材料, 2018, 51(10): 7-10, 15. Chen Lei, Song Huan, Li Zhengsheng, et al.Application progress of aramid fiber materials in electrical insulation and electronic fields[J]. Insulating Materials, 2018, 51(10): 7-10, 15. [4] Tan Chaoliang, Cao Xiehong, Wu Xuejun, et al.Recent advances in ultrathin two-dimensional nano-materials[J]. Chemical Reviews, 2017, 117(9): 6225-6331. [5] 王琳, 张美云, 杨斌, 等. 导热型芳纶纳米纸基绝缘材料的制备及性能[J]. 高分子材料科学与工程, 2020, 36(8): 42-50. Wang Lin, Zhang Meiyun, Yang Bin, et al.Preparation and properties of thermally conductive aramid nanofibers based insulating paper with boron nitrides[J]. Polymer Materials Science & Engineering, 2020, 36(8): 42-50. [6] 季家友. 芳纶Ⅲ表面改性及其与环氧复合体系的结构与性能研究[D]. 武汉: 武汉理工大学, 2012. Ji Jiayou.Effects of modification on aramid fibers and properties and structure of aramid/epoxy resin composites performance[D]. Wuhan: Wuhan University of Technology, 2012. [7] Lin Meiyan, Li Yinghui, Xu Ke, et al.Thermally conductive nanostructured, aramid dielectric composite films with boron nitride nanosheets[J]. Composites Science and Technology, 2019, 175: 85-91. [8] 李志辉, 解曾祺, 李庆民, 等. 多巴胺接枝的纳米氮化硼改性环氧树脂绝缘表面电荷高频消散特性[J]. 电工技术学报, 2023, 38(5): 1116-1128. Li Zhihui, Xie Zengqi, Li Qingmin, et al.Study on the surface charge dissipation characteristics of epoxy resin modified by dopamine grafted nano boron nitride under high frequency electric stress[J]. Transactions of China Electrotechnical Society, 2023, 38(5): 1116-1128. [9] Chen Jin, Huang Xingyi, Sun Bin, et al.Highly thermally conductive yet electrically insulating polymer/boron nitride nanosheets nanocomposite films for improved thermal management capability[J]. ACS Nano, 2019, 13(1): 337-345. [10] 米彦, 葛欣, 刘露露, 等. 微秒脉冲电场强度对BNNSs取向程度和环氧树脂复合材料热导率的影响[J]. 电工技术学报, 2022, 37(6): 1533-1541. Mi Yan, Ge Xin, Liu Lulu, et al.Effect of microsecond pulsed electric field strength on the BNNSs orientation degree and the thermal conductivity of epoxy resin composites[J]. Transactions of China Electrotechnical Society, 2022, 37(6): 1533-1541. [11] 张俊英, 郑乔文, 李宜珊, 等. 改性六方氮化硼/环氧粉末涂料的制备及性能测试[J]. 闽南师范大学学报(自然科学版), 2023, 36(4): 118-126. Zhang Junying, Zheng Qiaowen, Li Yishan, et al.Preparation and properties of modified hexagonal boron nitride/epoxy powder coating[J]. Journal of Minnan Normal University (Natural Science), 2023, 36(4): 118-126. [12] 李源, 萨日娜, 严岩, 等. 对位芳纶纤维的多巴胺仿生修饰及硅烷偶联剂二次功能化[J]. 橡胶工业, 2016, 63(1): 5-12. Li Yuan, Sa Rina, Yan Yan, et al.Functionalization on poly-p-phenylene terephthamide fiber using bioinspired dopamine deposition and silane coupling agent[J]. China Rubber Industry, 2016, 63(1): 5-12. [13] 姜楠, 李志阳, 彭邦发, 等. 等离子体羟基化改性纳米SiO2粒子对绝缘纸绝缘特性的影响[J]. 电工技术学报, 2023, 38(24): 6817-6827. Jiang Nan, Li Zhiyang, Peng Bangfa, et al.Effect of plasmas hydroxylation modified nano-SiO2 particles on insulation characteristics of insulating papers[J]. Transactions of China Electrotechnical Society, 2023, 38(24): 6817-6827. [14] Liu Zhan, Li Junhui, Liu Xiaohe.Novel functionalized BN nanosheets/epoxy composites with advanced thermal conductivity and mechanical properties[J]. ACS Applied Materials & Interfaces, 2020, 12(5): 6503-6515. [15] Ruan Haoou, Xie Qing, Song Jingxuan, et al.Effect of organophilic group of coupling agent on the electrical performance of boron nitride/meta-aramid composite paper[J]. High Voltage, 2023, 8(4): 760-771. [16] 赵曼卿, 张博, 李健飞, 等. 基于分子动力学仿真的混合油中水分子扩散行为及其介电常数研究[J]. 电工技术学报, 2024, 39(3): 798-809, 900. Zhao Manqing, Zhang Bo, Li Jianfei, et al.Influence of natural ester and mineral oil blending on the diffusion behavior of water molecules and the dielectric properties[J]. Transactions of China Electrotechnical Society, 2024, 39(3): 798-809, 900. [17] 王成江, 周文戟, 范正阳, 等. 六方氮化硼纳米掺杂增强环氧树脂热学和力学性能的分子动力学模拟[J]. 绝缘材料, 2021, 54(1): 78-83. Wang Chengjiang, Zhou Wenji, Fan Zhengyang, et al.Molecular dynamics simulation on thermal and mechanical properties of h-BN nano-doping enhanced epoxy resin[J]. Insulating Materials, 2021, 54(1): 78-83. [18] 李亚莎, 孟凡强, 章小彬, 等. 纳米SiO2掺杂对有水环境下间位芳纶绝缘纸性能影响的研究[J]. 原子与分子物理学报, 2020, 37(3): 371-377. Li Yasha, Meng Fanqiang, Zhang Xiaobin, et al.Study on theinfluence of nano-SiO2 doping on the performance of meta-aramid insulation paper in water environment[J]. Journal of Atomic and Molecular Physics, 2020, 37(3): 371-377. [19] 唐伟. 聚合物结晶与导热性能的分子模拟研究[D]. 合肥: 安徽大学, 2017. Tang Wei.Molecular simulation study on crystallization and thermal conductivity of polymers[D]. Hefei: Anhui University, 2017. [20] 杨路, 庞锴, 王栋, 等. 纳米SiO2表面KH550接枝密度对改性纤维素绝缘纸力学性能与热稳定性的影响[J]. 绝缘材料, 2021, 54(1): 25-30. Yang Lu, Pang Kai, Wang Dong, et al.Influence of KH550 grafting density on surface of nano-SiO2 on mechanical properties and thermal stability of modified cellulose insulating paper[J]. Insulating Materials, 2021, 54(1): 25-30. [21] 李长云, 范延岐. 纳米SiO2改性聚丙烯薄膜热力学性能的分子动力学模拟[J]. 中国电机工程学报, 2025, 45(5): 2003-2016. Li Changyun, Fan Yanqi.Molecular dynamics simulation of thermodynamic properties of polypro-pylene modified with nano-SiO2[J]. Proceedings of the CSEE, 2025, 45(5): 2003-2016. [22] 庹星星. 对位芳纶纳米纤维复合膜的制备与性能研究[D]. 武汉: 武汉纺织大学, 2017. Tuo Xingxing.Study on preparation and properties of para aramid fiber composite membrane[D]. Wuhan: Wuhan Textile University, 2017. [23] 王争东, 曹晓龙, 杨淦秋, 等. 高压大功率IGBT用液晶环氧性能研究(一):热导率与耐热特性[J]. 电工技术学报, 2025, 40(1): 273-284. Wang Zhengdong, Cao Xiaolong, Yang Ganqiu, et al.Research on properties of liquid crystalline epoxy for high-voltage and large-power IGBT (part 1 ): thermal conductivity and heat resistance performance[J]. Transactions of China Electrotechnical Society, 2025, 40(1): 273-284. [24] Chantrenne P, Barrat J L.Finite size effects in determination of thermal conductivities: comparing molecular dynamics results with simple models[J]. Journal of Heat Transfer, 2004, 126(4): 577-585. [25] 黄超, 魏高升, 崔柳, 等. 介孔二氧化硅导热特性的分子动力学研究[J]. 工程热物理学报, 2024, 45(2): 551-557. Huang Chao, Wei Gaosheng, Cui Liu, et al.Molecular dynamics study on the thermal conductivity of mesoporous silica[J]. Journal of Engineering Thermo-physics, 2024, 45(2): 551-557. [26] Xie Fan, Qin Panliang, Zhuo Longhai, et al.Novel aramid paper-based materials with enhanced thermal conductivity via ZnO nanowire decoration on aramid fibers[J]. Journal of Materials Science: Materials in Electronics, 2018, 29(14): 12161-12168. [27] 朱孟兆, 陈玉峰, 辜超, 等. 基于分子动力学的无定形纤维素热力学性质仿真[J]. 高电压技术, 2015, 41(2): 432-439. Zhu Mengzhao, Chen Yufeng, Gu Chao, et al.Simulation on thermodynamic properties of amorphous cellulose based on molecular dynamics[J]. High Voltage Engineering, 2015, 41(2): 432-439. [28] 江明, 王志新, 邓钧波, 等. 间位与对位芳纶沉析纤维及其纸基绝缘材料的结构特性对比研究[J]. 绝缘材料, 2017, 50(1): 17-22. Jiang Ming, Wang Zhixin, Deng Junbo, et al.Structures and properties comparison of meta-aramid and para-aramid fibrid and their paper-based insulation materials[J]. Insulating Materials, 2017, 50(1): 17-22. [29] 贲素东. 含功能梯度相复合结构界面脱落行为及纳米弹簧力学性能的研究[D]. 无锡: 江南大学, 2016. Ben Sudong.Research on the debonding behavior of composite structures with functionally graded interphase and the mechanical properties of nano-springs[D]. Wuxi: Jiangnan University, 2016. [30] 张晓星, 陈霄宇, 肖淞, 等. 改性SiO2增强环氧树脂热力学性能的分子动力学模拟[J]. 高电压技术, 2018, 44(3): 740-749. Zhang Xiaoxing, Chen Xiaoyu, Xiao Song, et al.Molecular dynamics simulation of thermal-mechanical properties of modified SiO2 reinforced epoxy resin[J]. High Voltage Engineering, 2018, 44(3): 740-749. [31] 魏文涛, 王全龙, 武美萍, 等. 氮化硼纳米材料功能化改性及对聚合物基材性能调控研究进展[J]. 功能材料, 2023, 54(8): 8044-8053. Wei Wentao, Wang Quanlong, Wu Meiping, et al.Research progress in functional modification of boron nitride nanomaterials and their performance adjustment on polymer substrates[J]. Journal of Functional Materials, 2023, 54(8): 8044-8053. [32] 辛毅. 电力设备温度在线监测及预警系统的设计与实现[D]. 济南: 山东大学, 2013. Xin Yi.The design and realization of temperature online monitoring and warning system for electric power equipment[D]. Jinan: Shandong University, 2013. [33] 李云鹏, 王靖瑞, 李庆民, 等. 不同含水率下电—热耦合应力对油纸绝缘界面小分子气体扩散特性的影响机制[J]. 高压电器, 2023, 59(8): 12-21. Li Yunpeng, Wang Jingrui, Li Qingmin, et al.Influence mechanism of electro-thermal coupling stress on diffusion characteristics of small molecule gas of oil paper insulating interface under different water content[J]. High Voltage Apparatus, 2023, 59(8): 12-21. [34] Mehra N, Li Yifan, Zhu Jiahua.Small organic linkers with hybrid terminal groups drive efficient phonon transport in polymers[J]. The Journal of Physical Chemistry C, 2018, 122(19): 10327-10333. [35] 李亚莎, 王玮, 宋鹏, 等. 温度和直流电场对SiO2改性植物绝缘油中水分子扩散特性的影响[J]. 绝缘材料, 2023, 56(7): 96-101. Li Yasha, Wang Wei, Song Peng, et al.Effect of temperature and DC electric field on diffusion characteristics of water molecules in SiO2 modified vegetable insulating oil[J]. Insulating Materials, 2023, 56(7): 96-101. [36] 范晓舟, 杨瑞, 樊思迪, 等. 短切纤维含量对间位芳纶纸性能影响及其构效关系机理分析[J]. 电工技术学报, 2024, 39(21): 6921-6931. Fan Xiaozhou, Yang Rui, Fan Sidi, et al.Effect of chopped fiber concentration on PMIA paper properties and analysis of structure-activity relationship mecha-nism[J]. Transactions of China Electrotechnical Society, 2024, 39(21): 6921-6931 [37] Xia Long, Lu Siru, Zhong Bo, et al.Effect of boron doping on waterproof and dielectric properties of polyborosiloxane coating on SiO2f/SiO2 composites[J]. Chinese Journal of Aeronautics, 2019, 32(8): 2017-2027.
2025, Vol. 40 
