今日更新：Composite Structures 1 篇，Composites Part A: Applied Science and Manufacturing 1 篇，Composites Part B: Engineering 2 篇，Composites Science and Technology 1 篇Composite StructuresA multiscale study on warpage of multi-pinned composites induced by curing processJisiyuan Cheng, Yingjie Xu, Weihong Zhang, Weiwei Liudoi:10.1016/j.compstruct.2024.117951固化过程诱发多销复合材料翘曲的多尺度研究In this paper, we studied the curing process and curing-induced warpage of multi-pinned composite structures through a novel multiscale methodology. This method interconnects the curing kinetics, composite micromechanics, mesoscale depiction and equivalent property calculation of Z-pinned regions, and macroscale warpage prediction by transmitting the evolving degree of cure and cure-dependent material properties. This methodology was then experimentally validated. We also systemically illustrated how the multi-pinned composites evolve through the curing process and further analyzed the effects of Z-pin diameter, spacing, material, composite layup, and cure temperature profile on the curing-induced warpage. It shows that Z-pinning primarily alters the tensile, through-thickness thermal expansion, and through-thickness chemical shrinkage properties of composites throughout the curing. Composites with medium-diameter Z-pins, larger Z-pinning spacing, and carbon fiber Z-pins are found to show larger macroscale warpages. Compared with other unidirectional patterns, the [45°]n layup is more susceptible to curing-induced warpage. Furthermore, the cure temperature profile affects the warpages through the final degrees of cure.本文通过一种新颖的多尺度方法研究了多销钉复合材料结构的固化过程和固化诱发的翘曲。该方法将固化动力学、复合材料微观力学、Z 销区域的中尺度描述和等效性能计算以及宏观翘曲预测相互联系起来，传递不断变化的固化程度和与固化相关的材料性能。这一方法随后得到了实验验证。我们还系统地说明了多销复合材料在固化过程中的演变过程，并进一步分析了 Z 销直径、间距、材料、复合材料铺层和固化温度曲线对固化引起的翘曲的影响。结果表明，在整个固化过程中，Z 形钉主要改变了复合材料的拉伸、厚度热膨胀和厚度化学收缩性能。研究发现，采用中等直径 Z 形销钉、较大 Z 形销钉间距和碳纤维 Z 形销钉的复合材料会出现较大的宏观翘曲。与其他单向模式相比，[45°]n 层叠更容易受到固化引起的翘曲的影响。此外，固化温度曲线会通过最终固化度影响翘曲。Composites Part A: Applied Science and ManufacturingFlexible and highly conductive Ti3C2Tx/natural rubber composites with interconnected networks for high-performance electromagnetic interference shieldingZiheng Ye, Daqiang Zhao, Feihua Liu, Jingjing Luo, Xiangli Liu, Weiwei Zhaodoi:10.1016/j.compositesa.2024.108067 具有互连网络的柔性高导电性 Ti3C2Tx/天然橡胶复合材料，用于高性能电磁干扰屏蔽Flexible composites showing highly conductive and outstanding electromagnetic interference (EMI) shielding performance with minimal thickness are urgently required for flexible electronics. Two-dimensional transition metal carbides and nitrides (MXenes) in fabricating conductive polymer composites have been revealed intensively. However, these composites need high MXene loading. Herein, by facile fast-forming approach, flexible Ti3C2Tx/natural rubber composites with 3D interconnected conductive networks were prepared, showing intact conductive framework and exhibiting outstanding electrical conductivity of 2,667 S m-1 with only 1.2 vol% Ti3C2Tx. The EMI shielding effectiveness (SE) surpassed 34 dB in the X-band with only 50 μm thickness. Furthermore, the strong interaction between natural rubber and low content Ti3C2Tx MXene nanosheets afforded the composites excellent flexibility and durability. Merely 2 dB decrease in EMI SE was revealed after being stretched to 5% for 10,000 times. The desirable conductivity, flexibility, and superior EMI shielding performance of Ti3C2Tx/NR composites pave a way in next-generation flexible electronics.柔性电子产品迫切需要具有高导电性和出色的电磁干扰（EMI）屏蔽性能且厚度极小的柔性复合材料。二维过渡金属碳化物和氮化物（MXenes）在制造导电聚合物复合材料方面的应用已得到深入研究。然而，这些复合材料需要较高的 MXene 负载。本文采用简便的快速成型方法制备了具有三维互连导电网络的柔性 Ti3C2Tx/天然橡胶复合材料，其导电框架完好无损，导电率高达 2,667 S m-1，而 Ti3C2Tx 的含量仅为 1.2 vol%。在 X 波段，厚度仅为 50 μm 的 EMI 屏蔽效果 (SE) 超过了 34 dB。此外，天然橡胶与低含量 Ti3C2Tx MXene 纳米片之间的强相互作用为复合材料提供了出色的柔韧性和耐用性。在拉伸 10,000 次至 5%后，EMI SE 仅下降了 2 分贝。Ti3C2Tx/NR 复合材料具有理想的导电性、柔韧性和优异的 EMI 屏蔽性能，为下一代柔性电子器件的发展铺平了道路。Composites Part B: EngineeringOne-pot solvent-free green strategy to fabricate ultra-efficient polyphosphoester flame retardant for Poly(Lactic acid)Zhicheng Bai, Feixiang Yin, Jiahao Shen, JinJia Xu, Fengqing Chen, Teng Huang, Hufeng Li, Dan Xie, Yi An, Wenbiao Zhang, Jinfeng Daidoi:10.1016/j.compositesb.2024.111236 一锅法无溶剂绿色制备聚乳酸超高效聚磷酯阻燃剂Tremendous attention has been dedicated to crafting eco-friendly flame retardants with excellent comprehensive performance via green means. Herein, a novel ultra-efficient polyphosphoester (PPE) flame retardant was synthesized via a facile one-pot method of solid-phase polycondensation reaction. PPE was then employed as a multifunctional additive for high-performance poly (lactic acid) (PLA). Benefiting from the dual-phase flame-retardant effect, the resultant PLA composite with merely 0.5 wt% PPE exhibited a desired limiting oxygen index (LOI) value of 26.1 %, and a satisfactory V0 rating of UL-94 (1.6 mm) with well-preserved mechanical properties. Due to the nucleating effect of PPE on PLA, the mechanical properties and crystallization ability of the PLA composites were both gradually enhanced as PPE content increased from 0.3 to 1.5 wt%. The designed ultra-efficient approach, enhancing fire safety and mechanical properties simultaneously at a low content, lays a foundation of an affordable, eco-friendly, and versatile flame retardant for potential applications of PLA.通过绿色手段制备综合性能优异的环保型阻燃剂一直备受关注。本文通过一种简便的单锅固相缩聚反应方法合成了一种新型超高效聚磷酸酯（PPE）阻燃剂。随后，PPE 被用作高性能聚乳酸（PLA）的多功能添加剂。得益于双相阻燃效应，PPE 含量仅为 0.5 wt% 的聚乳酸复合材料的极限氧指数 (LOI) 值达到了理想的 26.1%，V0 等级达到了令人满意的 UL-94 (1.6 mm)，并具有良好的机械性能。由于 PPE 对聚乳酸的成核作用，随着 PPE 含量从 0.3 wt% 增加到 1.5 wt%，聚乳酸复合材料的机械性能和结晶能力都逐渐增强。所设计的超高效方法可在低含量下同时提高防火安全性和机械性能，为聚乳酸的潜在应用奠定了经济、环保和多功能阻燃剂的基础。End group capturing in polyurea elastomer by using aromatic dianhydrides for flame retardanceHongyang Deng, Lixian Guo, Keping Chen, Pingfeng You, Ping Zhang, Yewei Xu, Ningning Song, Chunrong Tian, Jianhua Wang, Shuen Liangdoi:10.1016/j.compositesb.2024.111276 利用芳香族二酐捕获聚脲弹性体中的末端基团以实现阻燃效果Polyurea (PU) elastomers have become increasingly popular in recent years due to their exceptional blast mitigation, ballistic protection, and wear resistance properties. However, their applications as protective materials are often limited as a result of their high flammability. In this study, aromatic dianhydrides (ArDAs) were employed to capture the thermal decomposing products of PU during combustion and facilitate the generation of highly heat-resistant aromatic polyimides (i.e., end group capturing effect), thus enhancing the material's char-forming ability and improving its flame retardancy. The ArDAs were found to significantly reduce the peak heat release rate (PHRR), total heat release (THR), total smoke release (TSR), and total CO release (TCO) of PU, and meanwhile increased the amount of char residue. At 20 wt% content of 3,3′,4,4′-benzophenonetetracarboxylic dianhydride (BTDA), PHRR, THR, TSR and TCO of PU were reduced by 70.6%, 32.5%, 44.7% and 58.8%, respectively, the char residue was increased by 405%, and the mechanical properties of PU were well maintained (88.5% tensile strength and 91.0% elongation at break of pure PU). These findings demonstrate that ArDAs could serve as a new kind of halogen/phosphorus-free flame retardant for PU elastomers.近年来，聚脲（PU）弹性体因其优异的防爆、防弹和耐磨性能而越来越受欢迎。然而，由于其易燃性较高，其作为防护材料的应用往往受到限制。本研究采用芳香族二酐（ArDAs）来捕获聚氨酯在燃烧过程中的热分解产物，促进生成高耐热性芳香族聚酰亚胺（即端基捕获效应），从而增强材料的成炭能力并改善其阻燃性。研究发现，ArDAs 能显著降低聚氨酯的峰值热释放率（PHRR）、总热释放率（THR）、总烟雾释放率（TSR）和总 CO 释放率（TCO），同时增加炭残留量。当 3,3′,4,4′-二苯甲酮四羧酸二酐（BTDA）的含量为 20 wt%时，聚氨酯的 PHRR、THR、TSR 和 TCO 分别降低了 70.6%、32.5%、44.7% 和 58.8%，残炭量增加了 405%，聚氨酯的机械性能保持良好（纯聚氨酯的拉伸强度为 88.5%，断裂伸长率为 91.0%）。这些研究结果表明，ArDAs 可用作聚氨酯弹性体的一种新型无卤/无磷阻燃剂。Composites Science and TechnologyMultifunctional heterostructured composite foam with tunable electromagnetic interference shieldingShuaibing Wang, Zhu Wang, Si Yu Zheng, Jintao Yangdoi:10.1016/j.compscitech.2024.110482 具有可调电磁干扰屏蔽功能的多功能异质结构复合泡沫Multifunctional composite materials with adjustable electromagnetic interference (EMI) shielding properties hold significant promise in the emerging field of combating electromagnetic radiation pollution. Herein, we construct a heterostructured composite foam with tunable EMI shielding performance by adjusting the thickness and spatial distribution of Ag conductive network in the porous sponge, coupled with the incorporation of CNTs/WPU aerogel. The remarkable conductivity of 3D Ag network within the composite foam enables it possesses excellent shielding performance at X-band (47.1 dB), fast sensing response time (∼0.2 s), and high temperature of 101.8 °C through efficient joule heating even at a low voltage of 3 V. Importantly, controllable tuning of EMI shielding effectiveness (from 25.0 to 40.1 dB), are successfully achieved by changing the position of the Ag layer or compression strain of the composite foam. These achievements underscore the substantial potential of this material for creating electromagnetic shielding solutions with adaptable characteristics.具有可调电磁干扰（EMI）屏蔽性能的多功能复合材料在应对电磁辐射污染的新兴领域大有可为。在本文中，我们通过调整多孔海绵中银离子导电网络的厚度和空间分布，并结合 CNTs/WPU 气凝胶，构建了一种具有可调电磁干扰屏蔽性能的异质结构复合泡沫。复合泡沫中三维银网络的卓越导电性使其在 X 波段（47.1 dB）具有出色的屏蔽性能，感应响应时间快（0.2 秒），即使在 3 V 的低电压下也能通过有效的焦耳加热达到 101.8 °C 的高温。这些成果凸显了这种材料在创造具有可调整特性的电磁屏蔽解决方案方面的巨大潜力。来源：复合材料力学仿真Composites FEM
