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【新文速递】2023年11月19日复合材料SCI期刊最新文章

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今日更新:Composite Structures 1 篇,Composites Part A: Applied Science and Manufacturing 3 篇,Composites Part B: Engineering 2 篇,Composites Science and Technology 2 篇

Composite Structures

Mechanical properties and failure behaviors of T1100/5405 composite T-joint under in-plane shear load coupled with initial defect and high-temperature

Li Guowei, Cao Ertai, Jia Ben, Zhang Xuanjia, Wang Wenzhi, Huang Heyuan

doi:10.1016/j.compstruct.2023.117722

T1100/5405 复合材料 T 型接头在平面剪切载荷、初始缺陷和高温作用下的力学性能和失效行为

The T1100/5405, a novel carbon fiber resin matrix composite, boasts superior specific strength, stiffness, and broad applicability. This study rigorously investigated the in-plane shear performance and thermally coupled damage failure mechanisms of this composite in a T-joint context under initial defects, being highly relevant for hypersonic vehicles in high-temperature environments. Experimental tests yielded mechanical property parameters and in-plane shear data for varying test temperatures (25℃, 150℃) and defect radius (0mm, 15mm). Compared to flawless samples at room temperature, the synergistic impact of high temperature and defects expedited the structural damage failure process, reducing load-bearing capabilities significantly. A numerical model was established based, on the inherent structural relationship of the cohesive zone model and the continuum damage mechanics of the composite, whose accuracy was confirmed by experimental data. Further analysis revealed that a high-temperature environment would exacerbate the damage failure process of initial defects. Specifically, as the temperature rose, the defect radius increased, thus diminishing the shear capacity of T-joint. The maximum structural ultimate load has been reduced by 67.54%, which was perfectly aligned with experimental results. Consequently, the study provides practical insights for the structural design of hypersonic vehicle composite.

T1100/5405 是一种新型碳纤维树脂基复合材料,具有优异的比强度、刚度和广泛的适用性。本研究严格研究了这种复合材料在初始缺陷条件下 T 型接头的面内剪切性能和热耦合损伤失效机制,这与高温环境下的高超音速飞行器高度相关。实验测试得出了不同测试温度(25℃、150℃)和缺陷半径(0 毫米、15 毫米)下的机械性能参数和平面剪切数据。与室温下的无缺陷样品相比,高温和缺陷的协同影响加速了结构的破坏过程,大大降低了承载能力。根据内聚区模型的固有结构关系和复合材料的连续损伤力学,建立了一个数值模型,其准确性得到了实验数据的证实。进一步的分析表明,高温环境会加剧初始缺陷的损坏失效过程。具体来说,随着温度的升高,缺陷半径增大,从而降低了 T 型接头的抗剪能力。最大结构极限载荷降低了 67.54%,与实验结果完全一致。因此,该研究为高超音速飞行器复合材料的结构设计提供了实用的启示。


Composites Part A: Applied Science and Manufacturing

Facile fabrication of low-content surface-assembled MXene in silicone rubber foam materials with lightweight, wide-temperature mechanical flexibility, improved flame resistance and exceptional smoke suppression

Chen Hai-Yang, Li Yang, Wang Peng-Huan, Qu Zhang-Hao, Qin Yu-Qing, Yang Ling, Li Jia-Yun, Gong Li-Xiu, Zhao Li, Zhang Guo-Dong, Gao Jie-Feng, Tang Long-Cheng

doi:10.1016/j.compositesa.2023.107907

在硅橡胶泡沫材料中轻松制造低含量表面组装 MXene,具有轻质、宽温机械柔性、更好的阻燃性和优异的抑烟性能

Silicone rubber foam (SiRF) is a promising porous material that is widely applied in various fields. However, its intrinsic flammability nature remains a significant challenge. One of the simplest and most economical solutions is to incorporate high content flame-retardant fillers. Unfortunately, such approach is limited by several drawbacks, including poor filler dispersion, difficulty in processing and negative effect on mechanical flexibility. Herein, we report a green and facile strategy for surface-assembling ultralow content of MXene sheets bonded onto the pore surface of SiRF via the effective foaming reaction process. The as-prepared MSiRF-0.2 composite at 0.2 wt% MXene exhibited lightweight characteristic, wide-temperature mechanical flexibility, UL94-V0 grade, limited oxygen index of >27%, and exceptional smoke suppression (reduction by 88.24%). Furthermore, flame-retardant mechanism was discussed based on the char structure observation. This study provides a novel approach for fabricating mechanically flexible and flame-retardant SiRF via in-situ reactive assembly of low content MXene sheets.

硅橡胶泡沫(SiRF)是一种前景广阔的多孔材料,被广泛应用于各个领域。然而,其固有的易燃性仍然是一个重大挑战。最简单、最经济的解决方案之一是加入高含量阻燃填料。遗憾的是,这种方法受到几个缺点的限制,包括填料分散性差、加工困难以及对机械柔韧性的负面影响。在此,我们报告了一种绿色简便的策略,即通过有效的发泡反应过程将超低含量的 MXene 片材粘合到 SiRF 的孔隙表面进行表面组装。所制备的 MXene 含量为 0.2 wt% 的 MSiRF-0.2 复合材料具有轻质特性、宽温机械柔韧性、UL94-V0 等级、限氧指数大于 27% 以及优异的烟雾抑制性能(减少 88.24%)。此外,还根据炭结构观察探讨了阻燃机理。这项研究为通过低含量 MXene 片材的原位反应组装制造具有机械柔韧性和阻燃性的 SiRF 提供了一种新方法。


Triple-shape memory polybenzoxazine resins and their composites

Luo Lan, Niu Zhihong, Hu Rongxiang, Zhang Fenghua, Liu Yanju, Leng Jinsong

doi:10.1016/j.compositesa.2023.107910

三重形状记忆聚苯并恶嗪树脂及其复合材料

Shape memory polymer (SMP) as a new type of smart material can be programmed into a temporary shape by external excitation. Benzoxazine is a novel thermosetting resin with excellent heat resistance, high glass transition temperature (Tg) and mechanical properties. Here, triple-shape memory polybenzoxazines with high Tg were obtained by copolymerization of phenol/polyetheramine with phenol/furanamine benzoxazines. Electrically driven composites were prepared using multi-walled carbon nanotubes, and the SMP electrically driven function was achieved by forming a complete and continuous conductive permeable network inside the composites, shape recovery can be completed in 15 s at 60v. Furthermore, at high temperatures the carbon residue rate is increased to 45 % at 800 °C, demonstrating the high performance of electrically driven shape memory polymer composites. The realization of the triple and electrically induced shape memory properties of shape memory polybenzoxazines broadens the way for their application in extreme high-temperature environments in aerospace and aviation.

形状记忆聚合物(SMP)作为一种新型智能材料,可在外部激励下被编程为临时形状。苯并恶嗪是一种新型热固性树脂,具有优异的耐热性、高玻璃化转变温度(Tg)和机械性能。在这里,通过苯酚/聚醚胺与苯酚/呋喃胺苯并噁嗪的共聚,获得了具有高 Tg 的三重形状记忆聚苯并噁嗪。利用多壁碳纳米管制备了电驱动复合材料,并通过在复合材料内部形成完整连续的导电渗透网络实现了 SMP 电驱动功能,在 60v 下 15 秒内即可完成形状恢复。此外,在高温条件下,800 °C 时的碳残留率提高到 45%,证明了电驱动形状记忆聚合物复合材料的高性能。形状记忆聚苯并恶嗪的三重形状记忆特性和电致形状记忆特性的实现,为其在航空航天领域极端高温环境中的应用拓宽了道路。


Flexible Multiwalled Carbon Nanotubes/cellulose nanofibers Membrane with Rapid Temperature Increasing Induced by Interface Strengthening

Chen Siyao, Chen Zhiyu, Ou Yangling, Lyu Junwei, Li Junning, Liu Xiangyang, Liu Yang

doi:10.1016/j.compositesa.2023.107911

通过界面强化快速升温的柔性多壁碳纳米管/纤维素纳米纤维膜

Towards advanced electrical heaters with superior Joule heating property, high electrical conductivity has always been critical issue. Herein, in addition to the commonly recognized factor of electrical conductivity, we proved that the composite interface poses significant effect on temperature increasing as electrical heaters. Specifically, direct fluorination utilizing F2/N2 was applied to selectively decorate the outer walls of multiwalled carbon nanotubes (MWCNTs) while keeping the inner tube intact, which was followed by compositing it with cellulose nanofibers (CNFs) to prepare F-MWCNTs/CNFs flexible membrane. Due to the enhanced electrostatic interaction at the interface and stronger phonon vibrational coupling, interfacial phonon diffusion was significantly improved, which facilitated a higher temperature increase rate in the F-MWCNTs/CNFs membrane compared to the unmodified MWCNTs/CNFs membrane when subjected to an electric field. This unique interfacial effect holds promise for the development of high-performance electrical heaters with rapid response.

为了实现具有卓越焦耳加热特性的先进电加热器,高导电率一直是一个关键问题。在本文中,除了公认的导电率因素外,我们还证明了复合界面对电热片的升温具有显著影响。具体来说,我们利用 F2/N2 直接氟化技术选择性地装饰了多壁碳纳米管(MWCNT)的外壁,同时保持内管完好无损,然后将其与纤维素纳米纤维(CNFs)复合,制备出 F-MWCNTs/CNFs 柔性膜。由于界面上的静电相互作用增强,声子振动耦合加强,界面声子扩散显著改善,与未改性的 MWCNTs/CNFs 膜相比,F-MWCNTs/CNFs 膜在电场作用下的升温速率更高。这种独特的界面效应为开发快速响应的高性能电加热器带来了希望。


Composites Part B: Engineering

Silicon carbide fiber manufacturing: Cost and technology

Yilmaz Sefa, Theodore Merlin, Ozcan Soydan

doi:10.1016/j.compositesb.2023.111101

碳化硅纤维制造:成本与技术

Significant advances have been made in the past decade concerning silicon carbide fiber manufacturing methods resulting in near-stoichiometric small-diameter fibers that meet the property requirements for most of the ceramic matrix composites (CMC) and nuclear applications. The manufacturing cost, however, remained prohibitively high, preventing the use of it in different applications requiring much lower cost. Silicon carbide (SiC) fiber reinforced CMC is dominated by the cost of SiC fiber which comprises more than 50 % of the finished part cost. This article provides insight into the SiC fiber manufacturing costs and highlights the need for an alternative SiC fiber precursor and manufacturing method. Analysis of the existing polycarbosilane (PCS)-based SiC fiber manufacturing shows that the crosslinking (curing) and raw material preparation steps are high-cost steps that need lower cost options. Alternative SiC fiber precursor should be sought for lowering the cost of SiC fibers.

在过去十年中,碳化硅纤维制造方法取得了重大进展,制造出了接近碳原子计量的小直径纤维,满足了大多数陶瓷基复合材料(CMC)和核应用的性能要求。然而,其制造成本仍然过高,无法用于成本要求低得多的不同应用领域。碳化硅(SiC)纤维增强 CMC 的主要成本是碳化硅纤维的成本,占成品部件成本的 50%以上。本文深入分析了碳化硅纤维的制造成本,并强调了替代碳化硅纤维前体和制造方法的必要性。对现有基于聚碳硅烷(PCS)的碳化硅纤维制造方法的分析表明,交联(固化)和原材料制备步骤成本较高,需要成本更低的方案。为降低碳化硅纤维的成本,应寻找替代的碳化硅纤维前驱体。


Interlaminar shear strength of Carbon/PEEK thermoplastic composite laminate: Effects of in-situ consolidation by automated fiber placement and autoclave re-consolidation

Pourahmadi Emad, Shadmehri Farjad, Ganesan Rajamohan

doi:10.1016/j.compositesb.2023.111104

碳/PEEK 热塑性复合材料层压板的层间剪切强度:通过自动纤维铺放和高压釜再固化进行原位固结的影响

Automated manufacturing techniques, such as Automated Fiber Placement (AFP), offer an opportunity over conventional manufacturing methods, such as autoclave curing, to save time and expenses. The present research focuses on evaluating the Interlaminar Shear Strength (ILSS) of Carbon/PEEK thermoplastic composite laminates manufactured by AFP in-situ consolidation and autoclave re-consolidation using the Short-Beam Shear (SBS) test. Additionally, a methodology is proposed to capture the differences observed in ILSS using a finite element simulation. In this respect, a thermoplastic laminate was fabricated using AFP in-situ consolidation. Baseline laminate was also produced by re-consolidating another AFP-made laminate inside the autoclave. A micrographic study was conducted to investigate the void content and fiber distribution resulting from each manufacturing process. The test results showed that the AFP technique results in an ILSS of the laminate that is 37 % lower than that of the autoclave-reconsolidated laminate. The distinct mechanical behaviour in the SBS test arising from in-situ consolidation and autoclave re-consolidation was differentiated in the finite element modeling utilizing cohesive elements. This distinction was achieved by numerically finding the proper interface strength properties based on the SBS experimental results. These interface properties serve as valuable input parameters for conducting further finite element modeling and analyses of Carbon/PEEK thermoplastic composite laminates manufactured by AFP in-situ consolidation.

与高压固化等传统制造方法相比,自动纤维铺放(AFP)等自动化制造技术可节省时间和费用。本研究的重点是利用短梁剪切(SBS)试验,评估通过 AFP 原位固化和高压釜再固化制造的碳/PEEK 热塑性复合材料层压板的层间剪切强度(ILSS)。此外,还提出了一种利用有限元模拟捕捉 ILSS 中观察到的差异的方法。为此,使用 AFP 原位固结法制造了一种热塑性层压板。通过在高压釜内重新固结另一种 AFP 制成的层压板,还制作了基准层压板。对每个制造过程中产生的空隙含量和纤维分布进行了显微照片研究。测试结果表明,AFP 技术使层压板的 ILSS 比高压釜再固化层压板低 37%。在 SBS 试验中,原位固结和高压釜再固结所产生的不同机械性能在利用内聚元素进行的有限元建模中得到了区分。根据 SBS 试验结果,通过数值计算找到了适当的界面强度属性,从而实现了这种区分。这些界面属性是对通过 AFP 原位固结法制造的碳/PEEK 热塑性复合材料层压板进行进一步有限元建模和分析的重要输入参数。


Composites Science and Technology

Metal coordination in polymer drives efficient phonon transfer through self-assembled microstructures

Zheng Shuxin, Mu Liwen, Zhang Suoying, Lu Xiaohua, Zhu Jiahua

doi:10.1016/j.compscitech.2023.110348

 

聚合物中的金属配位通过自组装微结构驱动高效声子传递

Molecular interactions such as hydrogen bond, van der Waals force, covalent bond in association with heat transfer in polymeric materials have been reported, while the relationship between metal-polymer coordination and thermal conduction has not been studied yet. In this work, the molecularly-assembled microstructure of the composites produced by metal coordination with polyvinyl alcohol (PVA) reveals a qualitative correlation between microstructure and thermal conductivity (TC). The ellipsoid-shaped domain and increased coil size create stable phonon transmission channels, which are beneficial for boosting TC by lengthening the mean free path of phonon propagation. Strong coordination between the metal ions and the hydroxyl groups in the polyvinyl alcohol chains results in competition between the inter- and intra-molecular OH–OH hydrogen bonds, which eventually takes precedence. Such coordination structure creates distinctive micro-crystal domains and is discovered to be essential for TC enhancement. Moreover, the power generation value of thermal conversion using PVA-H/2.0Fe(NO3)3 film is twice that of pure PVA-H film, which has higher and faster conversion efficiency. These materials have been demonstrated as excellent candidates for improving the conversion efficiency of thermoelectric devices. In summary, this work offers a new strategy for regulating TC through metal coordination and a fundamental comprehension of the link between metal coordination, microstructure, and TC in polymer composites.

氢键、范德华力、共价键等分子相互作用与高分子材料的热传导有关的研究已有报道,而金属-聚合物配位与热传导之间的关系尚未研究。在这项研究中,金属与聚乙烯醇(PVA)配位产生的复合材料的分子组装微观结构揭示了微观结构与热导率(TC)之间的定性相关性。椭圆形畴和增大的线圈尺寸形成了稳定的声子传输通道,通过延长声子传播的平均自由路径,有利于提高热导率。金属离子与聚乙烯醇链中的羟基之间的强烈配位导致分子间和分子内 OH-OH 氢键之间的竞争,最终以后者优先。这种配位结构形成了独特的微晶畴,被认为是提高热导率的关键。此外,使用 PVA-H/2.0Fe(NO3)3 薄膜进行热转换的发电值是纯 PVA-H 薄膜的两倍,转换效率更高、更快。这些材料已被证明是提高热电设备转换效率的绝佳候选材料。总之,这项工作提供了一种通过金属配位调节热电转换效率的新策略,并从根本上理解了聚合物复合材料中金属配位、微观结构和热电转换效率之间的联系。


Tailoring the mechanical and combustion performance of B/HTPB composite solid fuel with covalent interfaces

Jiang Yue, Leem Juyoung, Robinson Ashley M., Wu Shuai, Huynh Andy H., Ka Dongwon, Zhao Ruike Renee, Xia Yan, Zheng Xiaolin

doi:10.1016/j.compscitech.2023.110350

 

利用共价界面定制 B/HTPB 复合固体燃料的机械和燃烧性能

The development of high-performing solid fuels with desired mechanical and combustion properties is critical to future air-breathing propulsion systems for space exploration and hypersonic navigation. Boron (B)/hydroxyl-terminated polybutadiene (HTPB) composite has been studied for this purpose due to the high energy density (heat of combustion) of B and the appropriate processability and mechanical properties of HTPB. However, the weak interface between B and HTPB results in weakened mechanical properties, agglomerated B particles, and slow and inefficient combustion, especially for composites with high B loading (30 wt% and above). In this study, the effect of interface between B and HTPB on the combustion and mechanical performance of high-loading B/HTPB composites was investigated by surface functionalization of B particles. Three interfacial characteristics were compared: polar (pristine B)/nonpolar (HTPB), nonpolar (hydrocarbon-functionalized B)/nonpolar (HTPB), and covalently bonded (amine-functionalized B/HTPB) interfaces. It was found that both covalently bonded and nonpolar/nonpolar interfaces effectively reduced the aggregation of B particles in the HTPB matrix, even with up to 45 wt% B loading, thus promoting the combustion efficiency and burning rate. Moreover, covalently bonded interfaces in B/HTPB composites led to strain-hardening behaviors, resulting in enhanced strength, ductility, and toughness. This work highlights the significance of interface engineering in B/HTPB composites for the efficacy and safety of future air-breathing solid-fueled propulsion devices.

开发具有理想机械和燃烧特性的高性能固体燃料对于未来用于太空探索和高超音速导航的喷气推进系统至关重要。硼(B)/羟基封端聚丁二烯(HTPB)复合材料因其硼的高能量密度(燃烧热)以及 HTPB 的适当加工性和机械性能而被用于这一目的的研究。然而,硼和 HTPB 之间的弱界面会导致机械性能减弱、硼颗粒团聚、燃烧缓慢且效率低下,尤其是在硼含量较高(30 wt% 及以上)的复合材料中。本研究通过对 B 颗粒进行表面官能化处理,研究了 B 与 HTPB 之间的界面对高负载 B/HTPB 复合材料燃烧和机械性能的影响。比较了三种界面特性:极性界面(原始 B)/非极性界面(HTPB)、非极性界面(烃官能化 B)/非极性界面(HTPB)和共价键界面(胺官能化 B/HTPB)。研究发现,共价键界面和非极性/非极性界面都能有效减少 B 粒子在 HTPB 基质中的聚集,即使 B 的负载量高达 45 wt%,也能有效减少 B 粒子的聚集,从而提高燃烧效率和燃烧速率。此外,B/HTPB 复合材料中的共价键界面导致了应变硬化行为,从而提高了强度、延展性和韧性。这项研究强调了 B/HTPB 复合材料界面工程对于未来喷气式固体燃料推进装置的有效性和安全性的重要意义。



来源:复合材料力学仿真Composites FEM
ACTMechanicalSystemSTEPS振动复合材料燃烧航空航天UGECAD电场材料试验
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【新文速递】2023年11月21日复合材料SCI期刊最新文章

今日更新:Composites Part A: Applied Science and Manufacturing 3 篇,Composites Science and Technology 2 篇Composites Part A: Applied Science and ManufacturingEnhancing mechanical properties and thermal conductivity in polymer bonded explosives by multi-scale surface modification of carbon fibersHe Guansong, Wang Peng, Zhong Ruolei, Li Xin, Yin Huamo, Chen Jie, Liu Shijun, Yang Zhijiandoi:10.1016/j.compositesa.2023.107918通过对碳纤维进行多尺度表面改性,提高聚合物粘合炸药的机械性能和导热性能Poor interfacial interaction and strength largely restrict the overall performance and practical application of carbon fibers (CFs) reinforced composites. The favorable interfacial properties were the key to realize superior mechanical properties in composites. Herein, we reported a novel multi-scale surface modification strategy of CFs to strengthen interfacial properties. Based on chemical oxidation treatment, the surface of CFs was further in situ grafted by a crosslinked high-strength polymer network consisting of aromatic diisocyanate, graphene oxide (GO) and polyethylenen glycol (PEG), which significantly improved the interfacial bonding and mechanical strength of interface layer itself. Benefitting from this multi-scale surface treatment, a high-efficiency mechanical enhancement of polymer bonded explosives (PBX) was achieved. With only 0.3 wt% fiber content, the maximum tensile and compressive strength PBX composites were both significantly improved, which were 63% and 39% higher than those of pure PBX, respectively. Meanwhile, the thermal conductivity was also enhanced, yielding a significant synergistic enhancement effect. The interface failure mechanism of the composite under stress was clarified by the fracture morphology characterization. This study sheds a light for exploring novel surface modification and has the potential application in in high performance polymer composites.界面相互作用和强度差在很大程度上限制了碳纤维(CFs)增强复合材料的整体性能和实际应用。良好的界面性能是实现复合材料优异机械性能的关键。在此,我们报告了一种新型的多尺度碳纤维表面改性策略,以增强界面性能。在化学氧化处理的基础上,进一步在 CF 表面原位接枝由芳香族二异氰酸酯、氧化石墨烯(GO)和聚乙二醇(PEG)组成的交联高强度聚合物网络,从而显著提高了界面层本身的界面结合力和机械强度。得益于这种多尺度表面处理,实现了聚合物结合炸药(PBX)的高效机械增强。在纤维含量仅为 0.3 wt% 的情况下,PBX 复合材料的最大拉伸强度和抗压强度都得到了显著提高,分别比纯 PBX 复合材料高出 63% 和 39%。同时,热导率也得到了提高,产生了明显的协同增强效应。通过断口形貌表征,阐明了复合材料在应力作用下的界面失效机理。这项研究为探索新型表面改性提供了启示,具有在高性能聚合物复合材料中应用的潜力。Shape-memory polyurethane elastomer originated from waste PET plastic and their composites with carbon nanotube for sensitive and stretchable strain sensorZhou Xing, Wang Guosheng, Li Dexiang, Wang Qi, Zhu Keming, Hao Yaya, Xu Yueyang, Li Nengdoi:10.1016/j.compositesa.2023.107920 利用废 PET 塑料制成的形状记忆聚氨酯弹性体及其与碳纳米管的复合材料,用于灵敏且可拉伸的应变传感器Chemical recycling of polyethylene terephthalate (PET) bottles is prospective for reducing waste plastics. The transformation of waste PET into valuable composites in high efficiency still remains a formidable challenge. Here we report the synthesis of polyurethane elastomer (PUE) by using the degraded products from waste PET via one-pot chain extended process. Then, the composites composed of PUE as substrate with carbon nanotubes as fillers are applied in fabricating stretchable strain sensor. The results show that the degraded product was successfully introduced into the polyurethane chains. The PUE chains showed disordered stacking as the degraded product content increased, with the modulus and elongation at break were up to 763.9 %. The composites assembled strain sensors exhibited stable sensing performance and excellent durability after 1000 cycles at 20 % tensile strain. This may supply a path to efficiently recycle waste PET plastic into valuable and functional composites, and even devices.聚对苯二甲酸乙二酯(PET)瓶的化学回收利用在减少废塑料方面前景广阔。如何高效地将废弃 PET 转变为有价值的复合材料仍是一项艰巨的挑战。在此,我们报告了利用废弃 PET 的降解产物,通过一锅扩链工艺合成聚氨酯弹性体(PUE)的过程。然后,以聚氨酯弹性体为基材,碳纳米管为填料组成的复合材料被应用于制造可拉伸应变传感器。结果表明,降解产物被成功引入到聚氨酯链中。随着降解产物含量的增加,聚氨酯链出现了无序堆叠,模量和断裂伸长率高达 763.9%。组装应变传感器的复合材料在 20% 拉伸应变条件下循环使用 1000 次后,显示出稳定的传感性能和出色的耐用性。这为将废弃 PET 塑料有效回收利用为有价值的功能性复合材料甚至设备提供了一条途径。The simultaneously achieved high permittivity and low loss in tri-layer composites via introducing negative permittivity layerSong Xiaoting, Zhang Zidong, Fan Guohua, Liu Yao, Fan Runhuadoi:10.1016/j.compositesa.2023.107921通过引入负介电常数层,在三层复合材料中同时实现高介电常数和低损耗Dielectric composites with excellent power densities have garnered significant attentions in electrical systems and pulsed energy storage. However, the low permittivity and high dielectric loss are greatly limit their applications. Herein, we present a novel approach involving tri-layer composites, where a middle negative-έ layer is sandwiched between outer positive-έ layers. This design aims to realize the balance of comprehensive performances by the interfacial polarization and synergistic effect between positive and negative-έ layers. Amazingly, the composite with content 3-5-3 with the thickness ratio of 1:20:1 shows remarkable permittivity of 679 coupled with a low loss tangent of 0.017 @ 10kHz, which is approximately 141 times higher than PI matrix with 4.8 of permittivity. Remarkably, the composite with content 3-5-3 (1:1:1) exhibited an improved Ud and high η of 1.35 J/cm3 and 94.5%, respectively. This work presents a new class of tri-layer composites with negative-έ layer, whose design method is applicable in high-property dielectric composites.具有出色功率密度的介电复合材料在电气系统和脉冲储能领域备受关注。然而,低介电常数和高介电损耗极大地限制了它们的应用。在此,我们提出了一种涉及三层复合材料的新方法,即在外层正έ层之间夹入中间负έ层。这种设计旨在通过界面极化和正负έ层之间的协同效应实现综合性能的平衡。令人惊奇的是,厚度比为 1:20:1 且含量为 3-5-3 的复合材料显示出 679 的显著介电常数和 0.017 @ 10kHz 的低损耗正切,这比介电常数为 4.8 的 PI 基体高出约 141 倍。值得注意的是,3-5-3(1:1:1)含量的复合材料显示出更高的 Ud 值和更高的η 值,分别为 1.35 J/cm3 和 94.5%。这项研究提出了一种新型负έ层三层复合材料,其设计方法适用于高特性介电复合材料。Composites Science and TechnologyInterfacial reinforcement of carbon fiber composites through a chlorinated aramid nanofiber interphaseMamolo Steven U., Sodano Henry A.doi:10.1016/j.compscitech.2023.110351 通过氯化芳纶纳米纤维间相实现碳纤维复合材料的界面加固Carbon fiber-reinforced polymers (CFRPs) rely on a strong interfacial bond between the reinforcing fibers and polymeric matrix to yield the high strength and toughness expected by a composite material. Poor interfacial strength leads to sub-optimal load transfer and introduces stress concentrations, which can reduce overall performance and result in catastrophic failure. Aramid nanofibers (ANFs) have shown significant promise for interfacial reinforcement in polymeric composite systems due to their high tensile strength, large specific surface area, and abundant polar functional groups. However, due to the chemically inert nature of carbon fibers, ANFs do not readily bond to their surface – thus limiting their application to CFRPs. In this work, we demonstrate that chlorination of ANFs and oxygen plasma treatment of carbon fibers enables the formation of a chlorinated ANF (Cl-ANF) interphase through chemical and physical adsorption using a simple dip-coating process, while fully preserving the tensile strength of the carbon fibers. The Cl-ANF interphase yielded a 79.8 % increase in interfacial shear strength and a 33.7 % increase in short beam strength. By enhancing the interfacial bond between fiber and matrix without degradation of the fiber's tensile strength, this method provides a rapid and reliable process to improve the mechanical properties of CFRP composites.碳纤维增强聚合物(CFRP)依靠增强纤维与聚合物基体之间牢固的界面结合力来实现复合材料所期望的高强度和韧性。界面强度差会导致载荷传递效果不理想,并引起应力集中,从而降低整体性能并导致灾难性故障。芳纶纳米纤维(ANFs)具有拉伸强度高、比表面积大和极性官能团丰富等特点,因此在聚合物复合材料体系中的界面加固方面大有可为。然而,由于碳纤维的化学惰性,ANFs 不易与碳纤维表面结合,因此限制了其在 CFRP 中的应用。在这项工作中,我们证明了对 ANFs 进行氯化处理和对碳纤维进行氧等离子体处理后,可通过简单的浸涂工艺,利用化学和物理吸附作用形成氯化 ANF(Cl-ANF)相,同时完全保持碳纤维的抗拉强度。Cl-ANF 中间相使界面剪切强度提高了 79.8%,短束强度提高了 33.7%。通过增强纤维与基体之间的界面结合力而不降低纤维的抗拉强度,这种方法为提高 CFRP 复合材料的机械性能提供了一种快速可靠的工艺。Optimizing energy storage density of the multi–layer composite of poly(vinylidene fluoride) and nano–Ni plated CaCu3Ti4O12 with an ultralow filling contentGao Liang, Zhang Yuting, Xiao Qianqian, Gao Zhengwu, Wang Xuandoi:10.1016/j.compscitech.2023.110353 优化超低填充物含量的聚偏氟乙烯和纳米镍镀层 CaCu3Ti4O12 多层复合材料的储能密度Surface modification of nanoceramics with high dielectric constant can increase dielectric constant of polymer composites voiding excessive dielectric loss, however, low discharged energy density (Ud) of composites at a low loading limits potential applications in high–energy–storage devices under low electric field. Herein, Ni–plated CaCu3Ti4O12 nanoparticle (CCTO@Ni) is used to improve the electric properties of the poly(vinylidene fluoride) monolayer composites (C/PVDF), and an ultralow loading of 0.5 vol% promotes the largest Ud of 2.53 J/cm3 at 230 MV/m, resulting from MWS interface polarization and Coulomb barrier effect included by CCTO@Ni fillers, which is used to further prepare three kinds of multi–layer structured C/PVDF composites by solution casting layer by layer. Comprehensive testing shows that the PVDF–C/PVDF–PVDF–C/PVDF–PVDF five–layer film (P–C–P–C–P) enhances the dielectric constant and breakdown strength to contribute the maximal Ud of 6.65 J/cm3 at 297.8 MV/m, which is 118% larger than that of pure PVDF. Above excellent characteristics are attributed to the interface polarization of the middle C/PVDF layer and the alleviating and blocking effect of the middle and outer PVDF layers, which are clarified in depth by the finite element simulation and enhanced breakdown model.对具有高介电常数的纳米陶瓷进行表面改性可以提高聚合物复合材料的介电常数,从而避免过多的介电损耗,然而,复合材料在低负载时的低放电能量密度(Ud)限制了其在低电场下高能量存储设备中的潜在应用。在本文中,镀镍的 CaCu3Ti4O12 纳米粒子(CCTO@Ni)被用来改善聚偏氟乙烯单层复合材料(C/PVDF)的电性能,0.5 vol% 的超低负载可使其在 230 MV 下的最大放电能量密度达到 2.53 J/cm3。 CCTO@Ni 填料在 230 MV/m 时产生的 MWS 界面极化和库仑势垒效应,进一步通过逐层溶液浇注制备了三种多层结构的 C/PVDF 复合材料。综合测试结果表明,PVDF-C/PVDF-PVDF-C/PVDF-PVDF 五层薄膜(P-C-P-C-P)提高了介电常数和击穿强度,在 297.8 MV/m 时的最大 Ud 为 6.65 J/cm3,比纯 PVDF 大 118%。上述优异特性归功于中间 C/PVDF 层的界面极化以及中间和外层 PVDF 层的缓解和阻挡作用,有限元模拟和增强击穿模型深入阐明了这一点。来源:复合材料力学仿真Composites FEM

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