今日更新:Composites Part A: Applied Science and Manufacturing 1 篇,Composites Part B: Engineering 1 篇,Composites Science and Technology 1 篇
Density-controlled thermal and mechanical properties of vertically aligned graphite foam-based polymer composites
Lei Kang, Hongyu Niu, Liucheng Ren, Ruicong Lv, Shulin Bai
doi:10.1016/j.compositesa.2024.108436
垂直排列石墨泡沫基聚合物复合材料的密度控制热性能和力学性能
The problem of thermal management of electronic devices leads to high demand of thermal interface materials (TIMs) with high thermal conductivity (TC) and softness. In this work, graphite foam (GFoam) was used to fabricate silicon rubber (SR) matrix-based TIMs by stacking and vertical cutting method. The obtained 75 vol% GFoam(100)/SR shows a high through-plane TC of 330.33 W m−1 K−1 due to the vertically aligned graphite layers. A strong correlation between the properties of the composites and the density of the fillers is found, providing a new perspective to adjust the properties of the composites. Composites with different proportions of GFoam and graphite film (GF) were prepared to further enhance the mechanical properties without obvious sacrifice of the thermal management performance. We believe that the design principles proposed in this work will be important for developing high-performance thermal management materials.
电子器件的热管理问题导致了对具有高导热性和柔软性的热界面材料的高需求。本研究以石墨泡沫(GFoam)为材料,采用叠层和垂直切割的方法制备硅橡胶基TIMs。所得的75 vol% GFoam(100)/SR由于石墨层垂直排列,其通过面TC高达330.33 W m−1 K−1。研究发现,复合材料的性能与填料的密度之间存在较强的相关性,为调整复合材料的性能提供了新的视角。制备了不同比例的GFoam和石墨膜(GF)复合材料,在不明显牺牲热管理性能的前提下进一步提高了材料的力学性能。我们相信,在这项工作中提出的设计原则将是开发高性能热管理材料的重要。
Structure-property correlations study in biochar-enhanced polyamide composites for sustainable materials development
Hossein Baniasadi, Erlantz Liizundia, Zoe Paganelli, Nele Dammann, Lauri Välinen, Jukka Seppälä, Jukka Niskanen
doi:10.1016/j.compositesb.2024.111809
面向可持续材料开发的生物炭增强聚酰胺复合材料结构-性能相关性研究
This study explores the synthesis and characterization of polyamide/biochar composites via in situ polymerization of 12-aminolauric acid with varying biochar concentrations. The motivation behind this research is to enhance the properties of polyamide 12 (PA12) by integrating biochar, a sustainable material derived from biomass, to improve both performance and environmental impact. A detailed structure-property correlation analysis was conducted to assess the effects of biochar on PA12's morphology, mechanical behavior, crystallinity, thermal stability, viscoelastic performance, and environmental sustainability. Key findings include successful PA12 synthesis, confirmed by FTIR and 1H NMR spectroscopy. Increased biochar content led to a decrease in molecular weight and an increase in crystallinity from 27 % to 38 %, suggesting enhanced nucleation effects. SEM analysis showed excellent dispersion and compatibility of biochar within the PA12 matrix, leading to significant improvements in tensile strength (from 38 ± 1 MPa to 54 ± 2 MPa) and modulus (from 745 ± 30 MPa to 2055 ± 65 MPa). Rheological tests demonstrated shear-thinning behavior, facilitating effective extrusion-based 3D printing of a complex object with 50 wt% biochar. A life cycle assessment revealed substantial environmental benefits, including a net reduction of 1.83 kg·CO₂ equiv.·kg⁻1 due to the use of biochar derived from wood pyrolysis. These findings highlight the potential of PA12/biochar composites as environmentally sustainable structural materials, combining enhanced functional properties with significant ecological advantages.
本研究探讨了聚酰胺/生物炭复合材料在不同浓度生物炭下的原位聚合。这项研究背后的动机是通过整合生物炭(一种来源于生物质的可持续材料)来增强聚酰胺12 (PA12)的性能,以提高性能和对环境的影响。通过详细的结构-性能相关分析,评估了生物炭对PA12的形态、力学行为、结晶度、热稳定性、粘弹性和环境可持续性的影响。主要发现包括成功合成PA12,经FTIR和1H NMR谱证实。生物炭含量的增加导致分子量降低,结晶度从27%增加到38%,表明成核效应增强。SEM分析表明,生物炭在PA12基质内具有良好的分散性和相容性,抗拉强度(从38±1 MPa到54±2 MPa)和模量(从745±30 MPa到2055±65 MPa)显著提高。流变学测试显示剪切变薄行为,促进了50%生物炭的复杂物体的有效挤压3D打印。生命周期评估显示了巨大的环境效益,包括由于使用木材热解产生的生物炭而净减少1.83 kg·CO₂当量·kg - 1。这些发现突出了PA12/生物炭复合材料作为环境可持续结构材料的潜力,结合了增强的功能特性和显著的生态优势。
Microstructural strain localisation phenomena in fibre-reinforced polymer composites: Insights from nanoscale digital image correlation and finite element modelling
E. Van Vlierberghe, S.F. Gayot, N. Klavzer, C. Breite, T. Pardoen, Y. Swolfs
doi:10.1016/j.compscitech.2024.110842
纤维增强聚合物复合材料中的微结构应变局部化现象:来自纳米级数字图像相关和有限元建模的见解
Multiscale models for fibre-reinforced polymer composites currently lack experimentally validated microscale damage descriptors as input parameters. This work demonstrates the occurrence of strain localisation phenomena at the fibre/matrix level using nanoscale digital image correlation. Unidirectional carbon-fibre reinforced epoxy and glass-fibre reinforced PMMA composites were loaded in transverse compression in a scanning electron microscope. Radial and shear strain maps were extracted and compared with finite element simulations based on a conventional elastoplastic model. Near the interface, an interphase layer is present in the matrix, presumably due to locally different polymerisation conditions. A skin-core structure was found in carbon fibres, corresponding to an increased transverse modulus towards the interface.
纤维增强聚合物复合材料的多尺度模型目前缺乏实验验证的微尺度损伤描述符作为输入参数。这项工作证明了在纤维/基质水平上使用纳米级数字图像相关的应变局部化现象的发生。在扫描电镜下对单向碳纤维增强环氧树脂和玻璃纤维增强PMMA复合材料进行横向压缩加载。提取径向应变图和剪切应变图,并与基于传统弹塑性模型的有限元模拟结果进行比较。在界面附近,一个间相层存在于基体中,可能是由于局部不同的聚合条件。在碳纤维中发现了一种皮芯结构,对应于向界面方向增加的横向模量。