Polymer Testing最新文献_第7页

Upcycled PET vitrimer filaments via reactive extrusion for high strength heat resistant and repairable FDM parts 通过反应挤压升级PET玻璃体长丝，用于高强度耐热和可修复的FDM部件

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

Polymer Testing

Pub Date : 2025-10-31 DOI: 10.1016/j.polymertesting.2025.109027

Salah Sabeeh , Sameer Algburi , Q. Alkhawlani , Feryal Ibrahim Jabbar , Mohammed El-Meligy , Haitham A. Mahmoud

Global plastic waste streams motivate routes that convert polyethylene terephthalate into durable, repairable parts through additive manufacturing. The central question addressed is whether a continuous reactive-extrusion process can transform polyethylene terephthalate flakes into vitrimer filaments that deliver high strength, heat resistance, and repairability with practical energy and cost. Developed a twin-screw reactive-extrusion route that couples grafting and vacuum devolatilization with in-line drawing to 1.75 mm filament, and verified transesterification and imine exchange using infrared spectroscopy, solid-state carbon nuclear magnetic resonance, gel fraction, and Flory–Rehner analysis. Rheology and stress-relaxation defined a topology-freezing window of 120–145 °C and activation energies of 148–190 kJ mol⁻¹, guiding print settings and post-print repair schedules. Printing at 252–255 °C nozzle, 85 °C bed, and 0.20 mm layers produced consistent deposition; mechanical testing reached tensile strength up to 63 MPa, interlayer shear 28–30 MPa, and heat-deflection temperature of 120–125 °C. Weld repair at 150–180 °C restored about 80 % tensile strength, and five melt reprocessings retained about 95 % heat-deflection temperature with modest viscosity drift. Microscopy showed wider inter-bead necks and about 1.6 % porosity with nano-silica, consistent with tougher interfaces. Process energy use totaled 1.70 kWh kg⁻¹ and modeled cost was $1.69 kg⁻¹ with major contributions from feed at $0.752 and electricity at $0.345. The study demonstrates a scalable pathway to high-strength, heat-resistant, and repairable vitrimer parts from waste polyethylene terephthalate with quantified performance, energy, and cost.

全球塑料废物流激发了通过增材制造将聚对苯二甲酸乙二醇酯转化为耐用、可修复部件的路线。研究的核心问题是，连续反应挤出工艺是否可以将聚对苯二甲酸乙二醇酯薄片转化为具有高强度、耐热性和可修复性的玻璃钢长丝，并且具有实际的能源和成本。开发了一种双螺杆反应挤出路线，将接枝和真空脱挥发结合在一起，直列拉伸至1.75 mm长丝，并通过红外光谱、固体碳核磁共振、凝胶分数和Flory-Rehner分析验证了酯交换和亚胺交换。流变学和应力松弛定义了120-145°C的拓扑冻结窗口和148-190 kJ mol−1的活化能，指导打印设置和打印后修复计划。打印在252-255°C喷嘴，85°C床，0.20 mm层产生一致的沉积；力学测试达到抗拉强度63 MPa，层间剪切28 ~ 30 MPa，热挠曲温度120 ~ 125℃。150-180°C的焊缝修复恢复了约80%的抗拉强度，五种熔体再处理保留了约95%的热挠曲温度，并具有适度的粘度漂移。显微镜观察显示，纳米二氧化硅的孔隙率约为1.6%，与较硬的界面相一致。过程能耗总计为1.70 kWh kg - 1，模型成本为1.69 kg - 1，主要来自饲料的贡献为0.752美元，电费为0.345美元。该研究展示了一种可扩展的途径，可以从废弃的聚对苯二甲酸乙二醇酯中获得高强度、耐热和可修复的玻璃体部件，并具有量化的性能、能源和成本。

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引用次数: 0

Immobilization of methane monooxygenase in polyvinyl alcohol hydrogels for enhanced methanol production: Insights into catalytic efficiency and industrial applicability 在聚乙烯醇水凝胶中固定化甲烷单加氧酶以提高甲醇产量：对催化效率和工业适用性的见解

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

Polymer Testing

Pub Date : 2025-10-31 DOI: 10.1016/j.polymertesting.2025.109029

Taleeha Roheen , Shagufta Kamal , Saima Rehman , Ismat Bibi , Tanvir Ahmed , Osama A. Mohammed , Fatimah M. Alzahrani , Munawar Iqbal

The utilization of Sphingomonas-MT for the isolation of methane monooxygenases (MMO) has garnered significant attention due to the growing focus on selective activation of methane under moderate conditions, particularly for utilizing new sources of natural gas pollution, for controlling its emission in the environment. This study explores the immobilization of soluble methane monooxygenase (sMMO) within polyvinyl alcohol (PVA) hydrogel matrices, evaluating its catalytic performance, stability, and reusability to optimize the conversion of methane to methanol. Methane concentration less than 2 ± 0.5 g/L was found to be suitable for a higher methanotrophic growth rate (0.075 ± 0.5

μ_{\max}

h⁻¹) and sMMO production (2.5 ± 0.25 U) after 48 h. The polyvinyl alcohol immobilized soluble methane monooxygenase (PVA-sMMO) displayed the highest immobilization yield and immobilization efficiency of 78.20 ± 1.10 %, and 86.40 ± 1.25 %, respectively, under optimum conditions. The PVA-sMMO exhibits the highest activity (610 ± 1.15 Ug⁻¹ of PVA) and RSM analysis identified the optimal conditions for maximum enzyme activity as follows: temperature 38 °C, pH 7.72, inoculum size 3.8 mL, and a carbon-to-nitrogen (C: N) ratio 0.58, ensuring the robustness of PVA-sMMO in industrial processes. A high value of

K_{m}

(1.44 mM) for PVA-sMMO and superior reusability of about 70 % after ten cycles, highlight the potential for sustained methanol production. EDX spectra confirmed the successful covalent immobilization of sMMO on the gel. The study also tracked methanol production over time, revealing consistent yields and highlighting the potential of PVA-immobilized sMMO for continuous, sustainable enzymatic processes. The improved stability and reusability of the PVA-sMMO system enhance its suitability for large-scale applications, meeting the rising demand for eco-friendly and efficient methane conversion technologies.

利用Sphingomonas-MT分离甲烷单加氧酶（MMO）引起了人们的广泛关注，因为人们越来越关注甲烷在中等条件下的选择性活化，特别是利用新的天然气污染源，以控制其在环境中的排放。本研究探讨了可溶性甲烷单加氧酶（sMMO）在聚乙烯醇（PVA）水凝胶基质中的固定化，评估了其催化性能、稳定性和可重复使用性，以优化甲烷转化为甲醇。在此条件下，聚乙烯醇固定化可溶性甲烷单加氧酶（PVA-sMMO）的固定化率和固定化效率最高，分别为78.20±1.10%和86.40±1.25%。PVA- smmo表现出最高的PVA活性（610±1.15 Ug−1），RSM分析确定了酶活性最高的最佳条件为温度38°C， pH 7.72，接种量3.8 mL，碳氮比0.58，确保了PVA- smmo在工业过程中的鲁棒性。PVA-sMMO的高Km值（1.44 mM）和10个循环后约70%的卓越可重复使用性，突出了持续甲醇生产的潜力。EDX光谱证实了sMMO在凝胶上成功的共价固定。该研究还跟踪了一段时间内的甲醇产量，揭示了一致的产量，并强调了pva固定化sMMO在连续、可持续的酶促过程中的潜力。PVA-sMMO系统的稳定性和可重用性提高了其大规模应用的适用性，满足了对环保高效甲烷转化技术日益增长的需求。

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引用次数: 0

Effect of high-temperature high-speed airflow on the thermo-oxidative aging of epoxy polymer and composite: An experimental study 高温高速气流对环氧聚合物及复合材料热氧化老化影响的实验研究

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

Polymer Testing

Pub Date : 2025-10-29 DOI: 10.1016/j.polymertesting.2025.109019

Aurélien Doriat , Marco Gigliotti , Marianne Beringhier , Gildas Lalizel , Eva Dorignac , Patrick Berterretche , Matteo Minervino

The objective of this study is to investigate the effect of the airflow on the thermo-oxidative aging of polymer matrix composites (PMCs). Understanding how airflow affects the aging process is crucial for designing composite parts subjected to airflow conditions, such as in aeronautics. We conducted tests in an oven at 150 °C and in wind tunnel at Mach 0.85 to compare static and dynamic aging conditions. The airflow conditions are determined using a Reynolds Averaged Navier–Stokes (RANS) Computational Fluid Dynamic (CFD) simulation to estimate the pressure and temperature conditions at any point of the air-polymer interface. The oxidation is characterized by colorimetric and roughness testing. Based on our experimental data and simulation results, we show that the compressibility effect of the airflow affects the pressure field at the interface and the thermal boundary layer affects the temperature of the samples. The samples aged in the wind tunnel are always more oxidized than those aged under oven conditions. The airflow accelerates the thermo-oxidation by mainly increasing the static pressure.

研究了气流对聚合物基复合材料热氧化老化的影响。了解气流如何影响老化过程对于设计受气流条件影响的复合材料部件至关重要，例如在航空领域。我们在150°C的烘箱和0.85马赫的风洞中进行了测试，比较了静态和动态老化条件。采用雷诺平均纳维-斯托克斯（RANS）计算流体动力学（CFD）模拟来确定气流条件，以估计空气-聚合物界面任意点的压力和温度条件。氧化是由比色和粗糙度测试表征。基于实验数据和仿真结果，我们发现气流的压缩效应影响了界面处的压力场，热边界层影响了样品的温度。在风洞中老化的样品总是比在烘箱条件下老化的样品更容易氧化。气流主要通过增加静压来加速热氧化。

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引用次数: 0

Antibacterial coating of substrates based on cationic biocides-enhanced thin films of selected polystyrene-based copolymers 阳离子杀菌剂增强聚苯乙烯基共聚物薄膜衬底的抗菌涂层

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

Polymer Testing

Pub Date : 2025-10-28 DOI: 10.1016/j.polymertesting.2025.109020

Kateřina Hamalová , Viktorie Neubertová , Adéla Jagerová , Anna Kutová , Jan Novotný , Zdeňka Kolská

Developing antimicrobial coatings is an important challenge nowadays, significant for managing microbial contamination across various applications, including medical devices, food packaging, and waste management. This study examines the preparation, modification and characterization of specific polystyrene-block-polyisoprene-block-polystyrene (SIS) and polystyrene-block-polybutadiene-block-polystyrene (SBS) thin polymer films modified by selected cationic biocides (CB), namely chlorhexidine (CHX) and dodecyltrimethylammonium bromide (DTAB). Two approaches were used to prepare and modify polymer films. First, CBs were added directly to the polymer solution. Second, pristine samples were exposed to plasma or UV radiation and afterwards immersed in an ethanol solution of CBs. Morphology, chemical structure and surface properties of the samples were characterized. Furthermore, their stability was evaluated, with a focus on their antibacterial activity and adhesion to selected substrates. The antibacterial activity of films improved when modified with CHX, as demonstrated by testing against Escherichia coli and Staphylococcus aureus. Specifically, one of the CHX-modified samples resulted in a bacterial survival rate of only 0.2 % in comparison with the control, less than the survival rates observed in DTAB-modified samples. Surface characterization revealed that lower zeta potential and contact angle values exhibited a correlation with higher hydrophilicity and antimicrobial activity, especially for CHX-modified films. Particularly the effect of surface charge is significant and plays a vital role. This work demonstrates several positive results of incorporating antibacterial agents into a polymer matrix. It also provides new insights into these materials as potential antibacterial coatings for a wide range of applications.

开发抗菌涂层是当今的一项重要挑战，对于管理各种应用中的微生物污染具有重要意义，包括医疗设备，食品包装和废物管理。本研究采用阳离子杀菌剂（CB），即氯己定（CHX）和十二烷基三甲基溴化铵（DTAB）对聚苯乙烯-聚异戊二烯-嵌段聚苯乙烯（SIS）和聚苯乙烯-嵌段聚丁二烯-嵌段聚苯乙烯（SBS）聚合物薄膜进行了制备、改性和表征。采用两种方法制备和修饰聚合物薄膜。首先，将CBs直接添加到聚合物溶液中。其次，将原始样品暴露在等离子体或紫外线辐射下，然后浸入CBs的乙醇溶液中。对样品的形貌、化学结构和表面性能进行了表征。此外，还评估了它们的稳定性，重点是它们的抗菌活性和对选定底物的粘附性。经CHX修饰后，膜的抑菌活性得到了提高，对大肠杆菌和金黄色葡萄球菌的抑菌活性得到了验证。具体来说，其中一个chx修饰的样本与对照组相比，细菌存活率仅为0.2%，低于dtab修饰样本的存活率。表面表征表明，较低的zeta电位和接触角值与较高的亲水性和抗菌活性相关，特别是对于chx修饰的膜。其中，表面电荷的影响尤为显著，起着至关重要的作用。这项工作证明了将抗菌剂纳入聚合物基质的几个积极结果。它还为这些材料作为潜在的抗菌涂层提供了新的见解，具有广泛的应用前景。

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引用次数: 0

Formation of skin-core structure in filled room-temperature vulcanized polydimethylsiloxane after long exposure to moderate temperatures 室温硫化聚二甲基硅氧烷经长时间中等温度作用后填充的皮核结构的形成

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

Polymer Testing

Pub Date : 2025-10-28 DOI: 10.1016/j.polymertesting.2025.109022

Florian Feyne , Eric Le Bourhis , Florian Lacroix , Laurence Autissier , Julie Pepin , Olga Smerdova

This study highlights the formation of a skin-core effect inside a filled silicone rubber exposed to air for durations up to 600 days at temperatures between 30 °C and 70 °C. Coupling mechanical and physico-chemical characterisations reveal that the volatile components, such as crosslinking by-products and oligomers, evaporate from the elastomeric network during the exposure, resulting in the shrinkage of the sample. This phenomenon gives rise to the formation of a composition gradient from the sample's surface towards its core. All the samples become more brittle with ageing, but the tensile modulus increase only slightly at the longest durations and highest temperatures. More fillers are found on the outer surface while the infrared spectra in the core of the sample remain unaffected by neither the temperature nor the duration. The nanoindentation highlights gradients of elastic modulus on the cross-section and provides an estimation of the skin thickness. By wrapping the samples in aluminum foil, the evaporation of volatile components is prevented. The measured properties remain constant with the duration of thermal exposure even at the highest temperature.

这项研究强调了在30°C到70°C的温度下，在空气中暴露长达600天的填充硅橡胶内形成皮肤核心效应。耦合力学和物理化学特征表明，挥发性成分，如交联副产物和低聚物，在暴露过程中从弹性体网络中蒸发，导致样品收缩。这种现象导致了从样品表面到其核心的组成梯度的形成。随着时效的增加，所有样品都变得更脆，但拉伸模量在最长持续时间和最高温度下仅略有增加。外表面存在较多的填料，而样品芯部的红外光谱不受温度和持续时间的影响。纳米压痕突出了截面上弹性模量的梯度，并提供了对皮肤厚度的估计。用铝箔包裹样品，可防止挥发性成分的蒸发。即使在最高温度下，所测得的性能也随热暴露时间的延长而保持不变。

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引用次数: 0

Interplay of surface energy and rheology in biopolymer soil enhancement 表面能与流变性在生物聚合物土壤强化中的相互作用

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

Polymer Testing

Pub Date : 2025-10-25 DOI: 10.1016/j.polymertesting.2025.109018

Yiwei Fang , Jinxuan Ding , Wanchuan Liu , Damien Crowley , Justin Antonette , Haoyan Fang , Aniket Raut , David Sprouster , Xiaoyang Liu , Yu-Chung Lin , Dilip Gersappe , Miriam Rafailovich

Biopolymers such as xanthan gum (XG) and locust bean gum (LBG) hold great potential as eco-friendly alternative soil binders. In this work, we investigated the impact of XG/LBG mixtures on the unconfined compressive strength (UCS) of sand. The high strength of dry biopolymer/sand arises from the cohesion between solid polymer films and sand particles which supported by work of adhesion calculation and soil mechanics measurement. LBG exhibits much lower sand reinforcement efficacy because polymers unevenly distributed within sand matrix. The formation of a core-shell structure in LBG/sand is an interplay of surface free energy and viscoelastic properties of polymer solutions. This structure is altered when LBG mixed with XG at varying ratios as those physical properties changed due to the complexity of polymer chains association. By probing these factors, we aim to elucidate the role of surface energies and polymer physics in governing the strength of the sand/polymer network, thereby contributing to a more comprehensive understanding polymer-sand interface. The low strength of gels (G’ ∼10Pa) cannot solely account for the increased UCS of wet sand over 10 kPa. Instead, the high strength of biopolymer/sand is more likely derived from the granular particles with biopolymers as solid glue.

黄原胶（XG）和刺槐豆胶（LBG）等生物聚合物作为生态友好的土壤粘合剂具有巨大的潜力。在这项工作中，我们研究了XG/LBG混合物对砂的无侧限抗压强度（UCS）的影响。干性生物聚合物/砂的高强度是由固体聚合物膜与砂粒之间的内聚作用决定的，黏附力计算和土力学测量结果支持了这一结论。由于聚合物在砂基质中的分布不均匀，LBG的加固效果较差。LBG/砂中核壳结构的形成是聚合物溶液的表面自由能和粘弹性相互作用的结果。当LBG以不同的比例与XG混合时，这种结构会发生变化，因为聚合物链结合的复杂性改变了这些物理性质。通过探索这些因素，我们的目标是阐明表面能和聚合物物理在控制砂/聚合物网络强度方面的作用，从而有助于更全面地了解聚合物-砂界面。凝胶的低强度（G′~ 10Pa）不能完全解释湿砂在10 kPa以上的单轴抗压强度增加的原因。相反，生物聚合物/砂的高强度更可能来自于与生物聚合物作为固体胶的颗粒颗粒。

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引用次数: 0

Strain-induced crystallization and elastocaloric response in SLS-printed thermoplastic polyurethane sls印刷热塑性聚氨酯的应变诱导结晶和弹热响应

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

Polymer Testing

Pub Date : 2025-10-24 DOI: 10.1016/j.polymertesting.2025.109014

A. Vaz-Romero , A. Montoya , J.P. Fernández-Blázquez , S.C. Cifuentes

In this work, we investigate the elastocaloric performance (eCE) of thermoplastic polyurethane (TPU) processed via Selective Laser Sintering (SLS), an additive manufacturing technique with significant yet underexplored potential in this field. A comprehensive experimental methodology was developed, which combines mechanical testing of V-notched specimens, infrared thermography, and in situ SAXS/WAXS analysis to simultaneously track mechanical, thermal, and structural evolution under cyclic loading. The experimental results reveal reversible adiabatic temperature changes of up to 5 °

C

, associated with strain-induced crystallization (SIC) and directional structural orientation. The use of a localized notched geometry (V-notched) enhanced the elastocaloric response at moderate global strains. Numerical modeling further confirmed the development of stress states favorable for SIC. These findings validate the elastocaloric functionality of SLS-printed TPU and offer new insights into processing–structure–property relationships. This work represents a step forward in the development of scalable, environmentally friendly cooling devices based on polymeric materials.

在这项工作中，我们研究了通过选择性激光烧结（SLS）加工的热塑性聚氨酯（TPU）的弹热性能（eCE），这是一种在该领域具有重要但尚未开发潜力的增材制造技术。开发了一种综合实验方法，将v形缺口试件的力学测试、红外热成像和原位SAXS/WAXS分析相结合，同时跟踪循环加载下的力学、热学和结构演变。实验结果表明，在应变诱导结晶（SIC）和定向结构取向的影响下，温度可发生高达5℃的可逆绝热变化。局部缺口几何形状（v形缺口）的使用增强了在中等全局应变下的弹热响应。数值模拟进一步证实了有利于SIC的应力状态的发展。这些发现验证了sls打印TPU的弹性功能，并为加工-结构-性能关系提供了新的见解。这项工作代表了基于聚合物材料的可扩展、环保冷却装置的发展向前迈出了一步。

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引用次数: 0

Poroviscoelastic characterization of polyacrylamide–alginate hydrogels across a broad range of length scales using torsional and depth sensing indentation tests 聚丙烯酰胺-海藻酸盐水凝胶的孔粘弹性特性在广泛的长度范围内使用扭转和深度感测压痕测试

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

Polymer Testing

Pub Date : 2025-10-23 DOI: 10.1016/j.polymertesting.2025.109015

C. Reinhards – Hervás , J. Rodríguez , A. Rico

The poroviscoelastic behavior of polyacrylamide (PAAm) and PAAm/alginate hydrogels is investigated through torsional and spherical indentation tests across multiple scales. The results reveal that both hydrogel types exhibit mechanical responses governed by viscoelastic and poroelastic mechanisms, with their relative contributions depending on contact scale and time. Torsional tests, which exclude fluid flow, showed purely viscoelastic relaxation, with increased stiffness and reduced relaxation in hydrogels with higher crosslinking density or alginate content. In indentation tests, relaxation time increased with contact size, indicating strong poroelastic influence. A constrained fitting model was applied to decouple both contributions and extract key material parameters such as diffusivity and relaxation modulus. Increased crosslinking enhanced both stiffness and diffusivity, while alginate addition improved stiffness but reduced diffusivity and Poisson's ratio. The consistency between results from both testing modes validates the proposed separation approach. Overall, this work demonstrates that multiscale poroviscoelastic characterization enables accurate understanding of the mechanical behavior of complex hydrogels.

通过多尺度的扭转和球形压痕试验，研究了聚丙烯酰胺（PAAm）和PAAm/海藻酸盐水凝胶的孔粘弹性行为。结果表明，两种类型的水凝胶均表现出粘弹性和孔弹性机制的力学响应，其相对贡献取决于接触尺度和时间。扭转测试（不包括流体流动）显示出纯粹的粘弹性松弛，在交联密度较高或海藻酸盐含量较高的水凝胶中，刚度增加，松弛减少。在压痕试验中，松弛时间随接触尺寸的增大而增加，表明孔隙弹性影响较强。采用约束拟合模型对两者进行解耦，提取关键材料参数，如扩散系数和松弛模量。增加交联可以提高刚度和扩散系数，而添加海藻酸盐可以提高刚度，但降低扩散系数和泊松比。两种测试模式结果的一致性验证了所提出的分离方法。总的来说，这项工作表明，多尺度孔隙粘弹性表征能够准确理解复杂水凝胶的力学行为。

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引用次数: 0

A biomimetic composite scaffold with near-infared light controlled shape-memory properties for bone defect healing 一种具有近红外光控制形状记忆特性的骨缺损修复仿生复合支架

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

Polymer Testing

Pub Date : 2025-10-20 DOI: 10.1016/j.polymertesting.2025.109005

Yao Yang , Zhennuo Shi , Ruqing Bai , Weihu Yang , Jifang Zhou , Li Wang

In this study, a shape-memory 3D scaffold with photothermal capability to heal bone defect was developed by a multifunctional porous composite network. The fabrication contains in-situ polymerization with gas foaming process, by incorporating surface-modified iron oxide nanoparticles (functionalized by polydopamine) into a biodegradable polyurethane matrix derived from poly(propylene glycol) and poly(ε-caprolactone) precursors. Enhanced osteoinductive signaling through these bioactive surface, enabling controlled mineralization and cell-matrix interactions. Robust osteogenic differentiation of mesenchymal stem cells across interconnected networks. Reversible shape memory transition (melting transition at 37 °C) enabling minimally invasive deployment through 4 mm diameter cannulas. Synergistic therapeutic effects combining localized heat shock protein induction with sustained bioactive ion release. This programmable biomatrix platform addresses critical unmet needs in complex craniofacial and orthopedic reconstruction by integrating shape-morphing delivery, spatially controlled thermotherapy, and sequential bone regeneration cues within a single implantable system.

本研究采用多功能多孔复合材料网络制备了具有光热修复骨缺损的形状记忆3D支架。通过将表面修饰的氧化铁纳米颗粒（由聚多巴胺功能化）掺入由聚丙二醇和聚ε-己内酯前体制成的可生物降解聚氨酯基质中，采用气相发泡原位聚合工艺制备。通过这些生物活性表面增强骨诱导信号，实现控制矿化和细胞-基质相互作用。跨互联网络间充质干细胞的强大成骨分化。可逆形状记忆转变（37°C熔化转变），可通过直径4mm的套管进行微创部署。局部热休克蛋白诱导与持续生物活性离子释放相结合的协同治疗效果。这种可编程的生物基质平台通过在单个植入系统中集成形状变形输送、空间控制热疗法和顺序骨再生线索，解决了复杂颅面和骨科重建中关键的未满足需求。

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引用次数: 0

Can all lignins act as an antioxidant for polypropylene? 所有的木质素都能作为聚丙烯的抗氧化剂吗？

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

Polymer Testing

Pub Date : 2025-10-20 DOI: 10.1016/j.polymertesting.2025.109016

Ana Clelia Babetto , Lívia Maria Garcia Gonçalves , Eliada Andrade Silva , Benedito Santos Lima Neto , Andreia de Araújo Morandim-Giannetti , Sílvia Helena Prado Bettini

Lignin, a high-volume byproduct of the pulp and paper industry, contains sterically hindered phenolic hydroxyl groups that enable antioxidant activity in polymer systems. This study investigates the potential of three eucalyptus-derived lignins, referred to as L1, L2, and L3, extracted from black liquor via acid precipitation under varying conditions, as primary antioxidants in polypropylene (PP). The lignins exhibited distinct pH values: L1 (3.35), L2 (3.68), and L3 (7.97). A comprehensive characterization, combining structural, chemical, and molecular analyses, was performed to correlate intrinsic features with antioxidant efficiency in PP. Although extraction conditions influenced purity and functionality, only detailed characterization allowed reliable prediction of stabilization performance. Lignins with acidic pH values (L1 and L2) showed higher purity and a greater concentration of sterically hindered phenolic groups, correlating with enhanced antioxidant activity. Oxidative induction time (OIT), rotational rheometry, and size exclusion chromatography (SEC) confirmed the superior performance of L1 and L2. At 2000 ppm, PP-lignin formulations containing L1 or L2 exhibited significantly higher OIT values, viscosities, and molar masses compared to PP with conventional synthetic antioxidants. Structural differences between syringyl and guaiacyl units in L1 and L2 further influenced stabilization during high-temperature processing, with L2 demonstrating exceptional performance under elevated temperature, oxygen, and shear. This work highlights the importance of combining extraction strategies with advanced lignin characterization to predict antioxidant efficiency, while introducing methodologies that correlate rheological behavior with molar mass distribution. These findings support lignin's application as a cost-effective, bio-based, and high-performance antioxidant additive for recycled polypropylene.

木质素是纸浆和造纸工业的大量副产品，它含有立体受阻的酚羟基，使聚合物系统具有抗氧化活性。本研究调查了三种桉树衍生木质素的潜力，称为L1， L2和L3，在不同条件下通过酸沉淀从黑液中提取，作为聚丙烯（PP）的初级抗氧化剂。木质素表现出不同的pH值：L1 (3.35), L2（3.68）和L3（7.97）。结合结构、化学和分子分析，进行了全面的表征，将PP的内在特征与抗氧化效率联系起来。尽管提取条件会影响纯度和功能，但只有详细的表征才能可靠地预测稳定性能。pH值为酸性（L1和L2）的木质素纯度较高，其位阻酚基团浓度较高，抗氧化活性增强。氧化诱导时间（OIT）、旋转流变学和粒径排除色谱（SEC）证实了L1和L2的优越性能。在2000ppm时，与含有常规合成抗氧化剂的PP相比，含有L1或L2的PP-木质素配方的OIT值、粘度和摩尔质量明显更高。紫丁香基和愈创木酰基在L1和L2中的结构差异进一步影响了高温加工过程中的稳定性，L2在高温、氧气和剪切下表现出优异的性能。这项工作强调了将提取策略与先进的木质素表征相结合以预测抗氧化效率的重要性，同时引入了将流变行为与摩尔质量分布相关联的方法。这些发现支持木质素作为一种具有成本效益的、生物基的、高性能的再生聚丙烯抗氧化添加剂的应用。

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