Nonmetals from the waste printed circuit board (NPCB) is the byproduct of waste printed circuit board recycling industry. The recycling of tons of NPCB for a clean environment and value-added product is still a great challenge. In this work, the possibility and feasibility of using NPCB to fabrication value-added thermal management materials are evaluated for the first time. The mechanical properties, thermal conductivity, dielectric performance and heavy metal leachate were studied. Due to the high aspect ratio of NPCB, the maximum tensile strength of LDPE/GNP/NPCB composites are increased from 24.9 MPa to 36.2 MPa and storage modulus maintained at 1403 MPa in 100 °C. Such data is much higher than those reported in the literature for LDPE/GNP composites and shows great potential for thermal management products. When increased NPCB content to 50 wt%, finite element simulation indicated that graphite nanosheets (GNP) interconnect and more heat flux is propagated through thermal conductive filler. The maximum thermal conductivity of LDPE/GNP/NPCB composites is increased from 1.0 W/mK to 1.6 W/mK. Moreover, the electrical conductivity of all samples is above 10⁹ Ω cm, and the composites show low dielectric permittivity and dielectric loss, meeting the requirements of insulating and thermally conductive materials. The heavy metal leaching results show that after 20 days, the concentrations of Cu, Zn, Pb, Ba, Cr, and Ni ion are far below the regulatory limits. This work not only provides a promising strategy to resolve NPCB environment pollution but also value-added products in thermal management applications.

废印刷电路板（NPCB）中的非金属是废印刷电路板回收行业的副产品。为清洁环境和增值产品回收大量NPCB仍然是一个巨大的挑战。在这项工作中，首次评估了使用NPCB制造增值热管理材料的可能性和可行性。研究了力学性能，导热系数，介电性能和重金属渗滤液。由于NPCB的高纵横比，LDPE / GNP / NPCB复合材料的最大拉伸强度从24.9 MPa增加到36.2 MPa，并且在100°C下的储能模量保持在1403 MPa。这样的数据远高于LDPE / GNP复合材料文献中报道的数据，并显示出热管理产品的巨大潜力。当NPCB含量增加到50 wt％时，有限元模拟表明，石墨纳米片（GNP）相互连接，并且更多的热通量通过导热填料传播。LDPE / GNP / NPCB复合材料的最大热导率从1.0 W / mK增加到1.6 W / mK。而且，所有样品的电导率都在10以上⁹ Ωcm，并且该复合物显示出低介电常数和介电损耗，会议绝缘且热传导的材料的要求。重金属浸出结果表明，20天后，Cu，Zn，Pb，Ba，Cr和Ni离子的浓度远低于规定的限值。这项工作不仅提供了解决NPCB环境污染的有前途的策略，而且还提供了热管理应用中的增值产品。