Highly filled composites have received the urgent demands in various areas (i.e., electrical and thermal conductive materials) due to their many advantages (i.e., low cost and high comprehensive performance). However, it is challenging to simultaneously improve the processability and toughness of highly filled composites by adding a small amount of flow modifier. In this work, for the first time, a novel silicone/fluorine‐functionalized flow modifier (Si-DPF) with low surface energy is synthesized and incorporated into a highly filled magnesium hydroxide/linear low-density polyethylene (MH/LLDPE) composite (80:20 by weight) to simultaneously improve the processability, toughness and flame retardancy. The results show that Si-DPF is dominantly located at the interface between the MH particles and LLDPE matrix to form a core-shell structure, leading to the relatively homogeneous dispersion of the MH particles. The melt equilibrium torque of the MH/LLDPE composite is decreased by 48.9%, the notched impact strength is increased by more than 4 times, and the area under the stress-strain curves is increased by more than 9 times at 5 wt% loading of Si-DPF. Additionally, the corresponding limited oxygen index (LOI) value is increased to 63.8%. This work provides a facile and effective strategy to simultaneously enhance the processability, toughness and flame retardancy of highly filled polymer-based composites by only one kind of multi-functional flow modifier.

高填充复合材料以其低成本和高综合性能等诸多优点，在各个领域（即导电导热材料）受到了迫切的需求。然而，通过添加少量流动改性剂同时改善高填充复合材料的加工性和韧性是一项挑战。在这项工作中，首次合成了一种具有低表面能的新型有机硅/氟官能化流动改性剂 (Si-DPF)，并将其掺入高度填充的氢氧化镁/线性低密度聚乙烯 (MH/LLDPE) 复合材料中。 80:20（按重量计）以同时提高加工性、韧性和阻燃性。结果表明，Si-DPF主要位于MH颗粒与LLDPE基体的界面，形成核壳结构，导致MH颗粒相对均匀的分散。MH/LLDPE 复合材料的熔体平衡扭矩降低 48.9%，缺口冲击强度提高 4 倍以上，应力应变曲线下面积增加 9 倍以上。硅-DPF。此外，相应的限氧指数 (LOI) 值增加到 63.8%。这项工作提供了一种简便有效的策略，可以仅通过一种多功能流动改性剂同时提高高度填充的聚合物基复合材料的加工性、韧性和阻燃性。在 5 wt% Si-DPF 负载下，应力-应变曲线下的面积增加了 9 倍以上。此外，相应的限氧指数 (LOI) 值增加到 63.8%。这项工作提供了一种简便有效的策略，可以仅通过一种多功能流动改性剂同时提高高度填充的聚合物基复合材料的加工性、韧性和阻燃性。在 5 wt% Si-DPF 负载下，应力-应变曲线下的面积增加了 9 倍以上。此外，相应的限氧指数 (LOI) 值增加到 63.8%。这项工作提供了一种简便有效的策略，可以仅通过一种多功能流动改性剂同时提高高度填充的聚合物基复合材料的加工性、韧性和阻燃性。