Hao Jiang, Yuhui Xie, Mukun He, Jindao Li, Feng Wu, Hua Guo, Yongqiang Guo, Delong Xie*, Yi Mei and Junwei Gu*. Highly Thermally Conductive and Flame-Retardant Waterborne Polyurethane Composites with 3D BNNS Bridging Structures via Magnetic Field Assistance. Nano-Micro Letters, 2025, 17: 138. 2023IF=31.6.（1區(qū)材料科學(xué)Top期刊）
https://doi.org/10.1007/s40820-025-01651-1
Abstract
The microstructure design for thermal conduction pathways in polymeric electrical encapsulation materials is essential to meet the stringent requirements for efficient thermal management and thermal runaway safety in modern electronic devices. Hence, a composite with three-dimensional network (Ho/U-BNNS/WPU) is developed by simultaneously incorporating magnetically modified boron nitride nanosheets (M@BNNS) and non-magnetic organo-grafted BNNS (U-BNNS) into waterborne polyurethane (WPU) to synchronous molding under a horizontal magnetic field. The results indicate that the continuous in-plane pathways formed by M@BNNS aligned along the magnetic field direction, combined with the bridging structure established by U-BNNS, enable Ho/U-BNNS/WPU to exhibit exceptional in-plane (λ//) and through-plane thermal conductivities (λ⊥). In particular, with the addition of 30 wt% M@BNNS and 5 wt% U-BNNS, the λ// and λ⊥ of composites reach 11.47 and 2.88 W/(m·K) respectively, which representing a 194.2% improvement in λ⊥ compared to the composites with a single orientation of M@BNNS. Meanwhile, Ho/U-BNNS/WPU exhibits distinguished thermal management capabilities as thermal interface materials for LED and chips. The composites also demonstrate excellent flame retardancy, with a peak heat release and total heat release reduced by 58.9% and 36.9% respectively, compared to WPU. Thus, this work offers new insights into the thermally conductive structural design and efficient flame-retardant systems of polymer composites, presenting broad application potential in electronic packaging fields.
在聚合物電氣封裝材料中，優(yōu)化熱傳導(dǎo)通路的微觀結(jié)構(gòu)設(shè)計(jì)對(duì)于滿足現(xiàn)代電子設(shè)備對(duì)高效散熱管理和熱失控安全至關(guān)重要。因此，本研究開發(fā)了一種具有三維導(dǎo)熱網(wǎng)絡(luò)的復(fù)合材料（Ho/U-BNNS/WPU），通過同時(shí)引入磁性改性氮化硼納米片（M@BNNS）和非磁性有機(jī)接枝氮化硼納米片（U-BNNS）至水性聚氨酯（WPU）中，并在水平磁場下同步成型。研究結(jié)果表明，由M@BNNS沿磁場方向排列形成的連續(xù)面內(nèi)導(dǎo)熱通路，以及U-BNNS所構(gòu)建的橋接結(jié)構(gòu)，使Ho/U-BNNS/WPU復(fù)合材料表現(xiàn)出優(yōu)異的面內(nèi)（λ//）和面間（λ⊥）導(dǎo)熱性能。尤其是當(dāng)M@BNNS和U-BNNS的添加量分別為30 wt%和5 wt%時(shí)，復(fù)合材料的λ//和λ⊥分別達(dá)到11.47 W/(m·K)和2.88 W/(m·K)，其中λ⊥較單一取向M@BNNS復(fù)合材料提升了194.2%。此外，Ho/U-BNNS/WPU作為LED和芯片的熱界面材料展現(xiàn)出卓越的熱管理能力。同時(shí)，該復(fù)合材料還表現(xiàn)出優(yōu)異的阻燃性能，其峰值熱釋放速率和總熱釋放量相較于純WPU分別降低了58.9%和36.9%。因此，本研究為聚合物復(fù)合材料的導(dǎo)熱結(jié)構(gòu)設(shè)計(jì)及高效阻燃體系提供了新思路，并在電子封裝領(lǐng)域展現(xiàn)出廣闊的應(yīng)用前景。
論文亮點(diǎn)
1. 通過在聚合物基體中同時(shí)引入磁性填料改性的氮化硼納米片（M@BNNS）和非磁性填料U-BNNS，并在水平磁場下同步成型，成功制備出具有三維熱傳導(dǎo)通路的復(fù)合材料。
2. 得益于三維橋接結(jié)構(gòu)的微觀設(shè)計(jì)，僅添加5 wt%的U-BNNS，復(fù)合材料的面間導(dǎo)熱系數(shù)（λ⊥）便達(dá)到2.88 W/(m·K)，相較于單一取向的復(fù)合材料提升了194.2%。
3. 三維橋接結(jié)構(gòu)的復(fù)合材料還表現(xiàn)出優(yōu)異的阻燃性能，這主要?dú)w因于凝聚相和氣相的協(xié)同阻燃機(jī)制，有效降低了電子設(shè)備發(fā)生熱失控的風(fēng)險(xiǎn)。
第一作者：姜豪
郵件地址：jianghao0820@mail.nwpu.edu.cn
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