Supplementary Information files for Enhanced interfacial adhesion and mechanical performance of lightweight polyurethane foam reinforced with a low content of aligned magnetised short carbon fibres

Supplementary Information files for Enhanced interfacial adhesion and mechanical performance of lightweight polyurethane foam reinforced with a low content of aligned magnetised short carbon fibresAn increase in interfacial properties between the matrix, a polyurethane cellular foam, and the reinforcement, a short carbon fibre, led to improved mechanical properties of a light-weight composite. The carbon fibre surface modification was designed with two aims: to possess magnetic properties so the discontinuous fibres could be aligned on-demand during the manufacturing process via a weak magnetic field and, to promote interfacial adhesion between the matrix and the reinforcement. After surface treatment, functionalising and coating with magnetite nanoparticles created and deposited in situ via electrodeposition prior to their deployment, the fibres were susceptible to magnetic manipulation and orientation within the reacting foam. The fibre coating contributed to interfacial compatibilization between the matrix and the reinforcement. Comparing the results between unreinforced, reinforced with untreated fibre, and reinforced with magnetised fibre, the results show that: foam reinforced with a low %vol content, i.e. from 0.1%vol to 0.4%vol, of any of the fibres improved specific strength, stiffness and toughness in tension relative to the unreinforced cellular polymeric matrix without densification, modification of cell size or compromising their lightweight properties. The magnetised fibre-containing composites showed significantly improved mechanical properties, in particular in tension, when compared to the untreated fibres due to their enhanced interfacial adhesion and their alignment in the matrix. Results in compression only yielded improvement in compressive strength, with other properties being similar to the unreinforced matrices. No significant differences were observed between the magnetised (aligned fibres) and the untreated (randomly distributed) configurations in compression.

附加信息文件，旨在提升轻质聚氨酯泡沫与其增强材料——即短碳纤维之间界面结合强度及力学性能。该短碳纤维的表面改性旨在实现双重目标：首先，赋予纤维磁性，以便在制造过程中，通过弱磁场实现对纤维的定向控制；其次，促进增强材料与基体之间的界面粘附。通过电沉积法原位制备并涂覆磁铁矿纳米粒子后，纤维对磁操控和泡沫反应过程中的定向具有敏感性。纤维涂层有助于基体与增强材料之间的界面相容性。将未增强、未处理纤维增强以及磁化纤维增强的泡沫进行比较，结果显示：含有低体积分数（从0.1%vol至0.4%vol）的纤维增强泡沫，在不改变其轻质属性的情况下，相较于未增强的多孔聚合物基体，显著提升了其在拉伸条件下的比强度、刚度和韧性。与未处理的纤维相比，含有磁化纤维的复合材料在拉伸性能方面表现出显著改善，这主要归因于其增强的界面粘附性和在基体中的定向排列。压缩测试结果仅显示出压缩强度的提升，而其他性能与未增强基体相似。在压缩性能方面，磁化（定向纤维）与未处理（随机分布）配置之间未观察到显著差异。