Polymer Testing最新文献_第5页

Interfacial-engineered 3D nano-carbon networks for synergistic enhancement of thermal–electrical transport and anisotropic heat dissipation 界面工程三维纳米碳网络协同增强热电传输和各向异性散热

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-12-12 DOI: 10.1016/j.polymertesting.2025.109078

Lide Yang , Sisi Chen , Jia Chen , Jianmin Yuan , Guowen He , Hui Fu

Despite recent advances in flexible thermal management materials, achieving simultaneous high thermal conductivity (k) and mechanical flexibility remains fundamentally challenging. A bioinspired method is demonstrated through the design of sandwich-structured cellulose nanofiber (CNF) composite films incorporating high-loading functionalized graphene nanosheets (GNS) and carbon nanospheres (CSs). CNF-GNS-MWCNT/CMC-CS/CNF-GNS-MWCNT composite (CNFGs) films are prepared by vacuum-assisted assembly followed by thermal lamination and show sandwich-like composite structure. In this composite film, a continuous three-dimensional thermal/conductive network—where vertically aligned CSs bridge horizontally organized GNS layers—is constructed, achieving superior in-plane/through-plane k (10.63/3.02 W/m·K) and efficient thermal management capabilities, effectively mitigating heat accumulation in practical applications (e.g., reducing LED chip temperatures by ∼23 °C). Furthermore, the superior Joule heating performance of CNFGs is demonstrated due to their high electrical conductivity (σ, 762 S/m in-plane; 265 S/m through-plane), with a saturated temperature of 113 °C achieved at 2.8 V, highlighting their potential for advanced thermal management and electrothermal conversion applications. Concurrently, thanks to surface-functionalized GNS/CS serving as dynamic anchoring sites for CNF chains, the composite films achieve long-range interconnectivity, retaining excellent mechanical flexibility (∼3.5 % elongation at break at 60 wt%, approaching pure CNF) while preserving over 97 % of the original k even after 1000-fold folding cycles. This work presents a simple yet effective strategy for designing high-performance flexible conductive/heat conduction polymer composites, offering new insights into interface-engineered carbon-based hybrid materials for next-generation electronics and energy devices.

尽管柔性热管理材料最近取得了进展，但同时实现高导热系数(k)和机械柔韧性仍然具有根本性的挑战性。通过设计含有高负载功能化石墨烯纳米片（GNS）和碳纳米球（CSs）的三明治结构纤维素纳米纤维（CNF）复合膜，展示了一种生物启发方法。采用真空辅助组装-热叠层法制备CNF-GNS-MWCNT/CMC-CS/CNF-GNS-MWCNT复合膜，呈现三明治状复合结构。在这种复合薄膜中，构建了一个连续的三维热/导电网络，其中垂直排列的CSs桥接水平组织的GNS层，实现了卓越的面内/通面k （10.63/3.02 W/m·k）和高效的热管理能力，有效地减少了实际应用中的热量积累（例如，降低LED芯片温度约23°C）。此外，由于其高电导率（σ，平面内762 S/m；平面内265 S/m），在2.8 V下达到113°C的饱和温度，CNFGs具有优越的焦耳加热性能，突出了其在先进热管理和电热转换应用方面的潜力。同时，由于表面功能化的GNS/CS作为CNF链的动态锚定位点，复合膜实现了远距离互连，保持了优异的机械柔韧性（在60 wt%的断裂时延伸~ 3.5%，接近纯CNF），即使在1000次折叠循环后仍保留了97%以上的原始k。这项工作为设计高性能柔性导电/导热聚合物复合材料提供了一种简单而有效的策略，为下一代电子和能源设备的界面工程碳基混合材料提供了新的见解。

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引用次数: 0

Damage characteristics and structural optimization of PELE with gradient reactive filling penetrating steel targets 梯度反应填充穿透钢靶的PELE损伤特性及结构优化

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-11-21 DOI: 10.1016/j.polymertesting.2025.109054

Guowen Gao , Enling Tang , Zhe Zhai , Guolai Yang , Yafei Han

To enhance the radial velocity and damage effectiveness of fragments after PELE projectile penetration, Al/Ep/B reactive material was selected as the core filler. Ballistic gun tests were conducted to study the dynamic penetration of steel targets by PELE projectiles with different core structures. The damage mechanisms of fragments were analyzed through mass distribution statistics and three-dimensional morphological reconstruction, while high-speed imaging was used to quantitatively characterize the axial and radial velocity fields of the fragments. A numerical model corresponding to the experimental conditions was established using Autodyn, incorporating a subroutine to describe the equation of state of the reactive material. The results showed high consistency between the simulated fragment morphology and velocity distribution and the experimental data. To further optimize the reactive core structure, a deep neural network was employed to establish the relationship between material parameters, fragment mass, and radial velocity. Multi-objective optimization was performed using the Non-dominated Sorting Genetic Algorithm (NSGA-II), ultimately identifying the gradient configuration as the optimal solution. A comparison between the optimization results and numerical simulations showed less than 5 % error in key parameters, verifying the reliability of the optimization.

为了提高破片穿透后的径向速度和损伤效能，选择Al/Ep/B反应材料作为核心填充物。采用弹道炮试验研究了不同芯部结构的PELE弹对钢目标的动态侵彻。通过质量分布统计和三维形态重建分析碎片的损伤机理，并利用高速成像技术定量表征碎片的轴向和径向速度场。利用Autodyn软件建立了与实验条件相对应的数值模型，并引入了描述反应物质状态方程的子程序。结果表明，模拟的碎片形态和速度分布与实验数据具有较高的一致性。为了进一步优化反应芯结构，采用深度神经网络建立材料参数、破片质量和径向速度之间的关系。采用非支配排序遗传算法（NSGA-II）进行多目标优化，最终确定梯度构型为最优解。优化结果与数值模拟结果的对比表明，关键参数误差小于5%，验证了优化的可靠性。

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引用次数: 0

Multiaxial characterization of cross-ply and quasi-isotropic flax bio-composites using a modified Arcan fixture and digital image correlation 使用改进的Arcan夹具和数字图像相关技术对交叉铺层和准各向同性亚麻生物复合材料进行多轴表征

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-11-28 DOI: 10.1016/j.polymertesting.2025.109059

Zoran Bergant, Tomaž Kek, Andraž Maček, Miroslav Halilovič, Roman Šturm

This study investigates the mechanical behavior, stress–strain states and damage evolution of flax-fiber reinforced polymer composites under various loading angles using Arcan specimens with V-notches. Three stacking sequences, cross-ply [0/90]_4s, quasi-isotropic [45/−45/0/90]_2s, and angled cross-ply [45/−45]_4s, were examined to assess their response to combined tension and shear loading at angles of 0°, 45°, and 90°. Digital Image Correlation (DIC) was employed to capture detailed strain fields and principal strain orientations, enabling direct comparison with numerical predictions from finite element modelling. Results show that the [45/−45]_4s laminate exhibits superior shear load-bearing capacity due to the transformation of shear into tensile and compressive stresses within ±45° plies. Notch sensitivity varied significantly among laminates, with the [45/−45/0/90]_2s configuration showing greater damage tolerance, a smaller strength drop at off-axis angles, and a reduced notch effect compared to cross-ply laminates. The study reveals complex strain localization patterns and fiber-matrix interactions influencing crack initiation and propagation. These findings enhance the understanding of anisotropic damage mechanisms in natural fiber composites and provide valuable insights for optimizing biocomposite layups in structural applications subjected to multiaxial stress–strain states.

采用带v形缺口的Arcan试样，研究了不同加载角度下亚麻纤维增强聚合物复合材料的力学行为、应力-应变状态及损伤演化。研究了三种堆叠顺序，即交叉铺层[0/90]4s、准各向同性铺层[45/−45/0/90]2s和角度交叉铺层[45/−45]4s，以评估它们在0°、45°和90°角度下对联合张力和剪切载荷的响应。采用数字图像相关（DIC）捕获详细的应变场和主应变方向，从而可以与有限元模型的数值预测进行直接比较。结果表明：[45/−45]4s层合板在±45°层合层内剪切向拉、压应力的转变使其具有较好的剪切承载能力；缺口敏感性在层压板之间存在显著差异，与交叉层压板相比，[45/−45/0/90]2s结构具有更大的损伤容限，离轴角强度下降较小，缺口效应较小。研究揭示了复杂的应变局部化模式和纤维-基体相互作用对裂纹萌生和扩展的影响。这些发现增强了对天然纤维复合材料各向异性损伤机制的理解，并为在多轴应力-应变状态下结构应用中优化生物复合材料层提供了有价值的见解。

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引用次数: 0

Corrigendum to “A highly transparent and self-healing elastomer based on dynamically reversible heterocyclic interactions with enhanced toughness and outstanding rolling reliability” [Polymer Testing 147 (2025) 108803] “一种基于动态可逆杂环相互作用的高透明自愈弹性体，具有增强的韧性和出色的滚动可靠性”[聚合物测试147(2025)108803]的勘误表

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-12-26 DOI: 10.1016/j.polymertesting.2025.109077

Kiwon Choi , Hyeryeon Jeon , Youngmin Kim , Yongju Kim , Pyong Hwa Hong , Jong Hyuk Park , Min Jae Ko , Sung Woo Hong

引用次数: 0

Assessment of plastics’ biodegradability under soil conditions based on modified biodegradability testing methods 基于改良生物降解性试验方法的土壤条件下塑料生物降解性评价

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-12-12 DOI: 10.1016/j.polymertesting.2025.109076

Geun-Yong Ham , Tomonori Ishigaki , Satoru Ochiai , Masato Yamada , Kazuei Ishii

Plastics are vital but pose environmental challenges, particularly in soil ecosystems due to agricultural use and improper disposal. Biodegradable plastics (BPs) offer a potential solution, yet their real-world degradation remains uncertain. Laboratory tests such as ISO 17556 are widely applied, but they leave ambiguities regarding reactor setup, soil preparation, and operational conditions, resulting in inconsistent interpretations and limited reproducibility. This study modified the ISO 17556 framework by establishing a decision framework and a validated standard soil protocol. Preliminary respirometry tests identified Arakida-soil as a suitable base medium and demonstrated that compost addition elevates background respiration, obscuring sample degradation signals. Therefore, compost-free standard soil (sand:clay:soil AK = 70:10:20) was selected. Reactor operation was standardized using a 500 mL vessel, an initial 3–5 day aeration interval followed by 10-day intervals. Continuous respirometry (2-h logging) was integrated with time-resolved material characterization (ATR-FTIR, DSC, SEC), enabling direct comparison of mineralization dynamics with structural changes.

Three BP films with different polymer compositions were evaluated for 196 days. Results satisfied ISO 17556 validity criteria and revealed distinct mechanisms: Sample A (PHB–PBAT) degraded rapidly via bulk erosion, Sample C (PLA–PBAT) showed delayed but comparable mineralization, while Sample B (PLA–PBAT, higher PLA fraction) exhibited limited degradation. The modified methodology provides clarified operational guidance and reproducible metrics (including kinetic rate constants), improving the comparability and mechanistic understanding of BP biodegradation in soil.

塑料至关重要，但也带来了环境挑战，特别是由于农业使用和处置不当而对土壤生态系统造成的挑战。生物降解塑料（bp）提供了一种潜在的解决方案，但它们在现实世界中的降解程度仍不确定。ISO 17556等实验室测试被广泛应用，但它们在反应器设置、土壤准备和操作条件方面留下了歧义，导致解释不一致和可重复性有限。本研究通过建立决策框架和经过验证的标准土壤协议修改了ISO 17556框架。初步的呼吸测试确定了荒田土是合适的基础培养基，并证明堆肥增加了本底呼吸，模糊了样品降解信号。因此，选择无堆肥标准土（砂：粘土：土AK = 70:10:20）。使用500ml容器标准化反应器操作，初始曝气间隔为3-5天，然后间隔10天。连续呼吸测量（2小时测井）与时间分辨材料表征（ATR-FTIR， DSC， SEC）相结合，可以直接比较矿化动态与结构变化。对三种不同聚合物组成的BP膜进行了196天的评价。结果符合ISO 17556的有效性标准，并揭示了不同的机制：样品A （PHB-PBAT）通过大块侵蚀快速降解，样品C （PLA - pbat）表现出延迟但相似的矿化，而样品B （PLA - pbat， PLA含量较高）表现出有限的降解。改进后的方法提供了明确的操作指导和可重复的指标（包括动力学速率常数），提高了土壤中BP生物降解的可比性和机理理解。

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引用次数: 0

Preparation and optimization of carbon fiber paper for fuel cell applications: Effect of dispersants, pulp and hot-pressing parameters 燃料电池用碳纤维纸的制备与优化：分散剂、纸浆和热压参数的影响

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-12-11 DOI: 10.1016/j.polymertesting.2025.109072

Jingwen Ouyang , Teng Zhang , Jun Xu , Xiongqi Peng

As a critical component in proton exchange membrane fuel cells (PEMFCs), carbon fiber paper (CFP) functions as the gas diffusion layer (GDL) backing, providing mechanical support, electrical conductivity, and effective gas–liquid transport. This work introduces a controllable wet papermaking fabrication route that integrates a dual dispersant regulation, refined pulp reinforcement and orthogonal optimization of hot-pressing parameters. The approach effectively addresses the long-standing issues of uneven fiber dispersion and suboptimal resin infiltration in conventional CFPs. The combination of polyethylene oxide (PEO) and anionic polyacrylamide (APAM) at a total concentration of 0.15 wt% (1:1 by mass) effectively stabilized the dispersion of 6 mm chopped carbon fibers (CFs), reducing large floc (>10 mm²) coverage to 3.0 % and improving sheet uniformity. Furthermore, incorporating 20 wt% softwood pulp (45 °SR) provided sufficient structural integrity for green sheets to withstand subsequent resin impregnation and hot-pressing processes. The result identified 15 wt% phenolic resin, 6 MPa compaction pressure, and 300 °C curing temperature as the optimal combination. The resulting CFP exhibited a uniformly impregnated and homogeneously compressed structure, showing an average pore size of 19.60 μm, 142 % higher tensile strength than the lowest-performing sample, conductivity of 31 mΩ cm, thermal diffusivity of 8.18 mm²/s and permeability of 1.56 Darcy.

作为质子交换膜燃料电池（pemfc）的关键部件，碳纤维纸（CFP）作为气体扩散层（GDL）的支撑层，提供机械支撑、导电性和有效的气液输送。本文介绍了一种集双分散剂调节、精浆补强和热压参数正交优化于一体的可控湿法造纸工艺路线。该方法有效地解决了传统CFPs中纤维分散不均匀和树脂浸润不理想的长期问题。聚乙烯氧化物（PEO）和阴离子聚丙烯酰胺（APAM）的总浓度为0.15 wt%（质量比为1:1）的组合有效地稳定了6mm短切碳纤维（CFs）的分散，将大絮团（>10 mm2）覆盖率降低到3.0%，并改善了薄片的均匀性。此外，加入20%软木纸浆（45°SR）为绿色板材提供了足够的结构完整性，以承受随后的树脂浸渍和热压工艺。结果表明，酚醛树脂用量为15wt %，压实压力为6mpa，固化温度为300℃为最佳组合。制备的CFP具有均匀浸渍和均匀压缩的结构，平均孔径为19.60 μm，抗拉强度比最差样品高142%，电导率为31 mΩ cm，热扩散率为8.18 mm2/s，渗透率为1.56 Darcy。

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引用次数: 0

Preparation, characterization, and swelling–release behavior of sodium alginate microspheres loaded with multiple nutrients under variable environmental conditions 海藻酸钠微球的制备、表征及其在不同环境条件下的膨胀释放行为

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-11-27 DOI: 10.1016/j.polymertesting.2025.109058

Xiaolin Liu , Lu Tang , Zhenzhen Liu , Chunxiao Liu

This study developed a sodium alginate (SA)-based slow-release microsphere (SA-NPK) for encapsulating nitrogen (N), phosphorus (P), and potassium (K) fertilizers to enhance fertilizer utilization and reduce environmental pollution. The structure and nutrient loading of the microspheres were characterized using FTIR, XRD, and SEM. These results showed that the composite fertilizer was embedded in the porous network structure of the SA microspheres in the form of crystals. Furthermore, investigating the effects of different pH values and NaCl concentrations on the swelling behavior of the microspheres and nutrient release showed that the swelling behavior of the SA-NPK microspheres exhibited good responsiveness to both pH and sodium ion concentrations, with acidic environments and elevated NaCl concentrations promoting the release of encapsulated nutrients. After 72 h, the cumulative release amounts of N, P, and K reached 93.20–97.86 %, 71.78–81.25 %, and 90.48–93.45 %, respectively. Moreover, soil leaching experiments demonstrated good sustained-release performance, with cumulative nutrient release rates of 82 %, 62 %, and 86 % for N, P, and K after 15 days, respectively. The microspheres also exhibited favorable biodegradability, confirming their potential to minimize environmental impact. Overall, the SA-NPK microspheres provide a low-cost, eco-friendly, and biodegradable slow-release fertilizer system with promising applications in sustainable agriculture and horticulture.

本研究开发了一种海藻酸钠（SA）缓释微球（SA- npk），用于包封氮、磷、钾肥料，提高肥料利用率，减少环境污染。利用红外光谱（FTIR）、x射线衍射（XRD）和扫描电镜（SEM）对微球的结构和营养载荷进行了表征。结果表明，复合肥料以晶体形式嵌入在SA微球的多孔网络结构中。此外，研究不同pH值和NaCl浓度对SA-NPK微球溶胀行为和养分释放的影响表明，SA-NPK微球的溶胀行为对pH和钠离子浓度均表现出良好的响应性，酸性环境和NaCl浓度的升高促进了被封装养分的释放。72 h后，N、P、K的累积释放量分别达到93.20 ~ 97.86%、71.78 ~ 81.25%和90.48 ~ 93.45%。此外，土壤淋溶试验显示出良好的持续释放性能，15天后N、P和K的累积养分释放率分别为82%、62%和86%。微球还表现出良好的生物降解性，证实了它们对环境影响最小化的潜力。综上所述，SA-NPK微球是一种低成本、环保、可生物降解的缓释肥料体系，在可持续农业和园艺领域具有广阔的应用前景。

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引用次数: 0

Towards biaxial fatigue experiments of elastomers using square and cruciform geometries in planar tension conditions 平面拉伸条件下方形和十字形弹性体的双轴疲劳试验

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-11-29 DOI: 10.1016/j.polymertesting.2025.109060

Ali Esmaeili , Deepak George , Lewis Tunnicliffe , Ian Masters , Mokarram Hossain

Soft materials such as natural rubber, hydrogels, and biological tissues have anisotropic properties and are subject to cyclic biaxial loading during their service lives. This requires biaxial loading rather than uniaxial; however, no agreed standard protocol exists. Therefore, the aim of this study is to provide preliminary suggestions for reliable and consistent biaxial fatigue tests so that a good degree of biaxiality and efficiency can be thoroughly achieved. Several biaxial loading tests (equi-biaxial and unequal-biaxial) were conducted on natural rubber and ecoflex using different geometries including cruciform and square configurations. Three criteria were defined to evaluate the equi-biaxiality performance: (i) test function related to homogeneous strain distribution in the field of interest, (ii) degree of efficiency corresponding to the ratio of strain in the field of interest (gauge section located in the middle regions) to the maximum strain far from the middle area, and (iii) strain ratio, used for fatigue test. Results showed that cruciform geometry underperformed in equi-biaxiality criteria, i.e., samples possessed high uniaxial strain in the arm whereas the simple square geometry could reach a higher degree of biaxiality and efficiency. The highest equi-biaxiality performance was obtained for the optimized square geometry in such a way that a maximum equi-biaxial strain of 65 % was achieved in the field of interest while possessing a degree of efficiency of 0.66 and strain ratio of 1.96. A successful unequal-biaxial fatigue test of up to two million cycles was conducted on the optimized square specimen made of ecoflex. Finally, a new square configuration with circular cavity in the middle was suggested for future biaxial characterization and standardization of biaxial tests in which the numerical study yielded a degree of efficiency of 1 and strain ration of 2.12 manifesting a considerable improvement in the biaxiality performance.

软材料如天然橡胶、水凝胶和生物组织具有各向异性，在其使用寿命期间受到循环双轴载荷的影响。这需要双轴加载而不是单轴加载；然而，目前还没有达成一致的标准协议。因此，本研究的目的是为可靠和一致的双轴疲劳试验提供初步建议，从而彻底实现良好的双轴性和效率。对天然橡胶和ecoflex进行了几种双轴（等双轴和不等双轴）加载试验，采用不同的几何形状，包括十字形和方形配置。定义了三个评价等双轴性性能的标准：(i)与感兴趣区域内均匀应变分布相关的试验函数，（ii）感兴趣区域（位于中间区域的规范截面）应变与远离中间区域的最大应变之比对应的效率程度，以及（iii）用于疲劳试验的应变比。结果表明，十字形几何结构在等双轴性条件下表现不佳，即样品在臂部具有较高的单轴应变，而简单的方形几何结构可以达到更高的双轴性和效率。优化后的方形几何结构获得了最高的等双轴性能，在感兴趣的领域中获得了65%的最大等双轴应变，而效率度为0.66，应变比为1.96。对优化后的ecoflex方形试件进行了200万次的非等双轴疲劳试验。最后，提出了一种新的中间有圆腔的方形结构，用于未来的双轴特性和双轴试验的标准化，其中数值研究得出的效率度为1，应变比为2.12，表明双轴性能有了很大的改善。

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引用次数: 0

Self-nucleation enhances the stability of the polymorphs present in triple polymorphic polythioethers 自成核增强了三多晶聚硫醚中多晶物的稳定性

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-11-20 DOI: 10.1016/j.polymertesting.2025.109052

Leire Unanue , Jorge L. Olmedo-Martínez , Cuong Minh Quoc Le , Abraham Chemtob , Alejandro J. Müller

This work examines the self-nucleation of three different polymorphic alternating polythioether homopolymers, i.e., DMDS-alt-DVE, DMDS-alt-TEGDVE and DMDS-alt-BBDVE. The repeating unit of these materials consists of an identical sulfur-containing part and ether functionalities that vary in chemical structure. All of the materials show three different polymorphic crystal phases, denoted by their distinct melting temperatures as: very low-temperature melting phase (

{V L - T}_{m}

), low-temperature melting phase (

{L - T}_{m}

) and high-temperature melting phase (

{H - T}_{m}

). A detailed self-nucleation study was performed by differential scanning calorimetry (DSC) and polarized light optical microscopy (PLOM). The different self-nucleation Domains were determined for each of the polymers, and the polymorphs that formed in each Domain were assigned. Self-seeding promoted the crystallization of the highest thermodynamically stable phase that was present in a given polythioether (e.g., DMDS-alt-DVE) and substantially increased its quantity reducing the formation of less stable phases. PLOM was indispensable to identify the multiple polymorphs present in the samples. This work establishes a robust testing protocol for polymorph selection in sulfur-containing polymers and offers thermal processing parameters for achieving desired crystal structures in functional polymer materials.

本研究考察了三种不同的多晶交替聚硫醚均聚物的自成核，即DMDS-alt-DVE， DMDS-alt-TEGDVE和DMDS-alt-BBDVE。这些材料的重复单元由相同的含硫部分和化学结构不同的醚功能组成。所有材料均表现出三种不同的多晶相，其熔融温度分别为：极低温熔融相（VL−Tm）、低温熔融相（L−Tm）和高温熔融相（H−Tm）。通过差示扫描量热法（DSC）和偏振光光学显微镜（PLOM）进行了详细的自核研究。确定了每种聚合物的不同自核结构域，并对每个结构域中形成的多晶进行了分配。自播种促进了给定聚硫醚（例如，DMDS-alt-DVE）中存在的最高热力学稳定相的结晶，并大大增加了其数量，减少了较不稳定相的形成。PLOM是鉴定样品中存在的多个多态性必不可少的工具。这项工作为含硫聚合物的多晶选择建立了一个强大的测试协议，并提供了在功能聚合物材料中实现所需晶体结构的热加工参数。

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引用次数: 0

Mode-II interlaminar damage in carbon/epoxy composites fabricated via hot-press and vacuum-bagging techniques 热压和真空装袋技术制备的碳/环氧复合材料的ii型层间损伤

IF 6 2区材料科学 Q1 MATERIALS SCIENCE, CHARACTERIZATION & TESTING

Polymer Testing

Pub Date : 2026-01-01 Epub Date: 2025-11-20 DOI: 10.1016/j.polymertesting.2025.109055

K.J. Wong , H.A. Israr , T. Dickhut , S.S.R. Koloor , M.N. Tamin

Understanding mode II delamination in thermoset composites remains incomplete, particularly when fabrication-induced variability affects interfacial characteristics and fracture performance. This research fabricates unidirectional carbon/epoxy prepregs via hot-press (HP) and vacuum-bagging (VB) techniques and evaluates their interlaminar fracture behaviour through End-Notched Flexure (ENF) testing. Results indicate that the mode II fracture toughness (G_IIC) of VB specimens (1387 N/m) is approximately 33 % lower than that of HP specimens (2058 N/m). Scanning electron microscopy (SEM) reveals reduced shear cusp density and matrix cracking in VB specimens. Delamination behaviour is simulated using a symmetric Trapezoidal Traction-Separation Law (TTSL) with pseudo-plasticity parameter Γ = 0.99, which, aside from differing G_IIC values, employs a consistent set of cohesive parameters (interface stiffness k_IIC = 4.5 × 10⁵ MPa/mm and interface strength t_u,II = 100 MPa) to accurately reproduce the force-displacement response in both fabrication methods. A higher G_IIC value corresponds to greater crack extension (da) in simulated damage profiles, with da = 2.9 mm and 2.5 mm in HP and VB specimens, respectively. The numerical model is further validated using VB specimens with varied initial crack lengths, consistently producing reliable results. These outcomes validate the proposed unified framework, with all cohesive parameters, except for the experimentally determined G_IIC, which are kept constant (Γ, k_IIC and t_u,II). This approach significantly reduces the need for extensive parametric studies in numerical simulations, thereby improving efficiency and consistency.

对热固性复合材料II型脱层现象的理解仍然不完整，特别是当制造引起的变异性影响界面特征和断裂性能时。本研究通过热压（HP）和真空装袋（VB）技术制备单向碳/环氧预浸料，并通过端缺口弯曲（ENF）测试评估其层间断裂行为。结果表明：VB试样（1387 N/m）的II型断裂韧性（GIIC）比HP试样（2058 N/m）低约33%；扫描电镜（SEM）显示，VB试样的剪切尖密度降低，基体开裂。采用拟塑性参数Γ = 0.99的对称的四边形牵引分离律（TTSL）模拟分层行为，除了不同的GIIC值外，还采用了一组一致的内聚参数（界面刚度kIIC = 4.5 × 105 MPa/mm，界面强度tu，II = 100 MPa）来准确地再现两种制造方法中的力-位移响应。在模拟损伤剖面中，GIIC值越高对应的裂纹扩展（da）越大，HP和VB试件的da分别为2.9 mm和2.5 mm。采用不同初始裂纹长度的VB试样进一步验证了数值模型，得到了一致可靠的结果。这些结果验证了提出的统一框架，除了实验确定的GIIC保持不变（Γ， kIIC和tu，II）外，所有参数都具有内聚性。这种方法大大减少了数值模拟中大量参数研究的需要，从而提高了效率和一致性。

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