更强、更轻、更快：基于材料表征的航空航天工程轻量化

航空航天业正日益向轻量化方向发展，即在不牺牲机械强度、耐久性或性能的前提下，采用密度更低的材料。轻量化具有诸多优势，包括加快生产速度、提高能效以及改善可回收性。该方法的核心在于优化材料的强度重量比，使组件能够在保持或超越所需力学性能的同时，将总质量降至最低。

向轻量化方向的转变，与航空航天业向大规模、高产率生产转型的总体趋势相契合；这种转型要求能够更快速且具备可重复性地制造飞机、卫星及先进空中交通平台。在美国，NASA 致力于实现高效率制造，以提升美国的市场领导地位和成本效益^。1

轻量化得益于复合材料技术的进步，而复合材料现已成为航空航天领域的主导材料。预计未来六年，航空航天热塑性复合材料市场将以 16.8% 的复合年增长率增长，^这为能够满足该不断扩张市场独特需求的制造商提供了绝佳机遇。然而，生产用于航空航天领域的新一代轻质复合材料并非没有独特的挑战。本篇博文将探讨顶尖研究人员如何优化适用于航空航天领域的轻质高效复合材料，同时确保强度与性能不受影响。

夹层结构是一种多层高性能复合材料，由两层薄面板和一个轻质蜂窝状芯材组成。^这些材料具有高强度重量比和高刚度，使其成为航空航天应用的理想选择。有两种热分析技术适用于优化夹层结构，特别是在航空航天领域。热重分析（TGA）用于测定热稳定性和降解特性，帮助工程师选择在高温下不会丧失强度或发生失效的材料。差示扫描量热法（DSC）通过分析熔融、结晶和玻璃化转变行为，有助于确定理想的加工条件，并筛选出具有最佳相变特性的共混物。

研究人员利用 Waters TA Instruments 评估了不同的材料混合配方，开发出了新型 4D 打印生物基形状记忆夹层结构。^他们利用 Waters TGA 评估了新材料的热稳定性，证实了不同混合配方表现出几乎相同的热降解特性。他们利用符合 ASTM D3418 标准的 Waters DSC研究了熔融与结晶行为；结果显示，某些添加剂导致了玻璃化转变温度（Tg）的降低，且其中一种共混物表现出更显著的熔融吸热峰。这项分析对于确定不同混合物之间的差异以及选择最适合特定最终用途的混合物至关重要。

动态力学分析（DMA）为实现材料强度重量比的最大化提供了支持；该技术通过测量材料随时间、温度和频率变化的力学性能来进行分析。DMA（动态热机械分析）通过以下方式支持轻量化：量化储能模量以筛选高刚度、低质量的配方；表征阻尼特性（tan δ）以平衡结构刚度与振动耗散；以及监测热转变过程，确保材料在工作温度范围内保持足够的刚度。

高温推进系统依赖于BMI（双马来酰亚胺）等热固性材料，以利用其玻璃化转变温度（Tg）和热稳定性。NASA研究人员利用Waters DMA，在涵盖从低温到高温的典型火箭燃烧室工况下，对燃烧室用树脂进行了研究。测试结果证实，随着后固化温度的升高，玻璃化转变温度（Tg）^随之提高；但在低于Tg起始温度的所有温度范围内，模量均有轻微下降。

新型制造技术正在推动轻量化创新：感应焊接和超声波焊接能够高效实现大规模、高精度且品质一致的轻量化制造。DMA 通过评估储能模量和损耗模量随温度的变化情况，为焊接设计提供支持。研究人员利用^Waters DMA评估了预热对碳纤维/PEEK复合材料层合板超声波焊接的影响。数据表明，该材料的能量耗散能力随温度变化，这是焊接过程中生热的主要驱动因素。利用DMA（动态热机械分析），他们确定了损耗模量峰值——即材料将超声波振动转化为内部热能效率最高的点——并据此调整了预热工艺，以充分利用这一特性。

增材制造是另一种日益普及的轻量化材料生产方法，具有更高的自动化程度、复杂性、材料利用效率及设计灵活性。在近期的一项研究中，研究人员探讨了两种用于制造航空次承力结构碳纤维增强复合材料（ ^CFRP ）的增材制造方法。他们利用 Waters 动态热机械分析仪（DMA）研究了该材料的粘弹性行为与热转变特性，并使用热机械分析仪（TMA）测量了随时间、温度和力变化而产生的尺寸变化。他们发现，打印参数对尺寸稳定性有显著影响。

最后，热分析对于预测新型轻质材料的最终使用性能及安全性至关重要。例如，在开发用于飞机机身和机翼的复合材料T型接头时，研究人员利用DMA（动态热机械分析）、流变学和DSC（差示扫描量热法）研究了该接头在服役条件下的响应特性，以确保其在飞行过程中保持稳定。8^同样，Waters公司科学家发布的一份应用说明也展示了TGA（热重分析）在预测最终用途性能方面的重要性，因为它能够测定分解温度，并根据温度和时间估算聚合物的使用寿命^。9在这些研究中，热分析技术为那些专为严苛使用环境设计的新型轻质材料提供了最终用途性能预测支持，从而在降低风险的同时加速了创新进程。

上述研究表明，热力学分析对于验证轻质材料在严苛航空航天工况下的强度、使用寿命及稳定性至关重要。随着制造商不断追求更高的生产效率和更大幅度的减重，DSC、TGA、DMA 和流变学等技术提供了必要的数据，助力设计出不仅更轻，而且在整个使用寿命期间更安全、更可靠的材料。从优化加工条件到分析热降解，材料表征是实现轻量化安全与高效的基石。

1. Taminger, K. NASA 高速率航空结构技术计划；美国国家航空航天局，2020年。https://ntrs.nasa.gov/api/citations/20200004300/downloads/20200004300.pdf .
2. 拉贾特·佐佩。2032年航空航天热塑性复合材料市场规模与份额Persistence Market Research。https ://www.persistencemarketresearch.com/market-research/aerospace-thermoplastic-composites-market.asp （访问于 2026年5月18日）。
3. 嗯。Ilham Akbar; Bidayatul Armynah; Tahir, D. 夹层复合结构 (SCS)：以聚合物和金属为填料的木质电磁干扰（EMI）屏蔽材料研究综述Industrial Crops and Products 2024, 215, 118619–118619. https://doi.org/10.1016/j.indcrop.2024.118619 .
4. Ghalayaniesfahani, A.; Oostenbrink, B.; Kasteren, H. van; Gibson, I.; Mehrshad Mehrpouya.生物基形状记忆夹层结构的4D打印Polymer 2024, 307, 127252–127252. https://doi.org/10.1016/j.polymer.2024.127252 .
5. Stelter, C.; Park, C.; Chu, S.-H.; Hudson, T. 经历从低温到高温循环的复合材料缠绕燃烧室用后固化双马来酰亚胺树脂的动态力学分析。Nasa.gov. https://ntrs.nasa.gov/citations/20240012459 （访问于 2026-05-18）。
6. Takeda, S.; Kugi, D.; Hoshi, H.; Mohammad Fikry, MJ; Ogihara, S. 预热对CF/PEEK复合材料层合板超声波焊接的影响。Composite Structures 2025, 373, 119668. https://doi.org/10.1016/j.compstruct.2025.119668 .
7. Maier, R.; Istrate, AM; Despa, A.; Mandoc, AC; Bucaciuc, S.; Stoica, R. 增材制造技术制备的聚合物复合材料热力学响应研究。Materials 2022, 15 (14), 5069. https://doi.org/10.3390/ma15145069 .
8. 张涛, 罗震, 邓京, 裴雨, 程鑫. 基于预浸料-RTM共固化工艺的高弯曲性能复合材料螺栓连接T型接头制备新方法.Polymers 2024, 16 (9), 1259. https://doi.org/10.3390/polym16091259 .
9. Browne, J. 聚醚醚酮（PEEK）的热分析 – Waters TA Instruments。https ://www.tainstruments.com/applications-notes/thermal-analysis-of-polyether-ether-ketone-peek-ta496/ 。

When it comes to selecting materials for your next innovative product, the material specification sheet is likely the first place that you will turn. This document provides core properties measured by the manufacturer and serves as an essential tool for supplier verification and new product development. However, while these sheets are reliable and provide a standard method for comparison, they often fail to tell the whole story.

For successful material selection, product performance, failure prevention, it is important to go beyond the spec sheet and conduct in-house testing. This proactive approach will save you both time and money by facilitating informed material choices and enhancing product design.

A material specification sheet provides a snapshot of a material’s key properties as measured by the manufacturer. These properties are typically measured using standardized methods such as ASTM or ISO standards, offering some consistency and comparability across different materials. The spec sheet can be used for various purposes:

• Supplier Verification: Ensuring that the material provided by a supplier meets the necessary criteria for production.
• New Product Development: Aiding in the selection of new materials during the design phase of a product.

While spec sheets provide a foundational understanding, relying solely on them can be risky; they often provide incomplete information to know the material’s performance or predict lifetime of a product, especially in real-world application conditions.

Spec sheets are foundational for understanding general material properties, but they often lack detailed information about how a material will behave under specific conditions, such as the effects of different temperatures, prolonged stress or stress cycles, or exposure to harsh environments. Uncovering these blind spots is necessary for improving processing conditions, understanding material lifespan, and ultimately selecting the right material at the start of your development process.

To fully understand a material’s properties and ensure it meets your specific requirements, additional testing is required. Here are some critical aspects to consider:

Environmental Impacts

Materials can perform differently under various environmental conditions, such as UV exposure, or humidity. Due to the impracticality of inspecting materials in active use, such as polymer coatings on wires embedded in walls, a quick test lasting only a few minutes to hours is conducted to estimate the long-term stability of these materials over decades.¹

Differential scanning calorimetry (DSC) with oxidative induction time (OIT) analysis helps predict the aging and degradation of polymers, guiding material selection for longevity and reliability. For instance, polymers exposed to heat, oxygen, or light degrade faster, and OIT provides insights into their lifespan.

A variation of the OIT test, known as high-pressure OIT (HPOIT), is becoming increasingly popular. Proponents argue that oxidative data obtained under high pressure and temperature conditions align more closely with results from traditional, accelerated aging tests. The HPOIT test offers two primary advantages: high pressure raises the boiling points of additives, reducing their volatility, and it increases the concentration of the reacting oxidizing gas. This enables the use of lower test temperatures or significantly reduces test durations at comparable temperatures.²

Alternatively, high-pressure thermogravimetric analysis (HP-TGA) simulates extended exposure to harsh environments by using a combination of heat and elevated pressure. It is particularly useful for materials used in industrial applications, such as cabling for electrical or fiber optic systems. Safeguarding polymers against catastrophic degradation when exposed to direct sunlight or buried underground is crucial for these applications.³

Mechanical Behavior

Understanding the mechanical properties of materials beyond the scope of the datasheet is essential for nearly every application. For example, the following should be considered:

• Temperature Effects: Materials can exhibit drastically different properties at varying temperatures. Datasheets typically only list tensile properties at room temperature, but materials are frequently expected to perform under higher or lower temperatures.
• Long-Term Loading: What happens if a material is subjected to a load for weeks, months, or even years? Will it deform over time, i.e., creep? Will it crack under prolonged stress, i.e., creep rupture? For example, a clothing hanger may perform well under normal use, but storing a heavy coat over winter could cause the neck to elongate and eventually break. In this example, the clothing hanger began failing to perform its function (holding up clothes) due to creep and fell off the rod. Had it not fallen due to deformation, it would have eventually cracked due to creep rupture.

• Repeated Loading: In a process known as fatigue, repeated loading can cause accumulating damage, leading to fracture. It is important to know the stress levels and number of loading cycles a material can withstand before failure. Polymers exhibit fatigue in a very different way than metals and fatigue life estimates cannot be extrapolated from tensile strength as easily. Additionally, the usage temperature can have a significant impact on fatigue life at much lower temperatures than metals.

Mechanical test instruments evaluate durability and mechanical characteristics under various stresses (forces), frequencies, and environmental conditions. Specifically, Electroforce load frame instruments measure a sample’s response to force, whether it is a single push or pull (tensile test), repetitive load (fatigue), or creep/stress-relaxation test. Mechanical testing also accounts for environmental effects by testing in temperature-controlled air, gas, or fluid submersion.

Material testing is crucial in manufacturing and product development because it minimizes the risk of product failure, which can have costly and even dangerous consequences. Unexpected material behavior can lead to malfunctions, product recalls, and reputational damage.

For example, a woven fiberglass composite had a manufacturer’s recommended operating temperature up to 130°C. However, Dynamic Mechanical Analysis (DMA) testing revealed that the material’s storage modulus and loss modulus began to change around 100°C.⁴ Further fatigue testing data revealed that the material had a 90% reduction in its fatigue life at 100°C.⁵ Manufacturers could have mistakenly put this material into products used at high temperatures, such as baking, without realizing that it was highly likely to break.

Conducting thorough testing upfront provides higher confidence in material choices, ultimately saving time, money, and resources. Moreover, comprehensive material testing contributes to better long-term product reliability and performance. By thoroughly examining how a material responds to factors like fatigue, creep, and environmental degradation, manufacturers can design products that not only meet initial requirements but also maintain integrity throughout their life cycle. This proactive approach fosters innovation in product design, as engineers gain a deeper understanding of the material’s limits and capabilities, allowing for the creation of more efficient, safer, and longer-lasting products.

Going beyond the spec sheet is not just a recommendation; it is a necessity. By investing in additional testing, such as OIT using DSC and HP-TGA, you can uncover profound insights about material performance. By adding DMA and Electroforce fatigue testing to your testing suite, you can better predict material properties at various temperature conditions and repeat loading. These insights will ensure you make informed decisions that save time, money, and valuable resources by selecting the proper material for your application conditions. TA Instruments is here to support you with precision instruments and technical expertise, ensuring you have the tools needed to expertly evaluate materials and make the best decisions for your projects.

High-performance polymers are a critical material for manufacturers due to their combination of mechanical, thermal, and chemical properties, but especially their cost. Without adequate testing, manufacturers could run into a slew of issues, from immediate product failure to poor performance or failure after some time in usage. In this post, we review the three most important types of mechanical testing to better predict and ensure performance, safety and reliability.

As high-performance and technical industries innovate, so do the materials they use to build their products. A car company might have to design a specialized part to handle increased torque from an EV. An engineer might need to develop a novel storage solution for critical scientific cargo in a rocket headed to the International Space Station. No matter the goal, each component must perform safely, reliably, and predictably. Success requires a multi-faceted testing approach in the development stage, because the stakes could not be higher when a product reaches the real world (or leaves it).

Whether a new supplier is necessary because of lingering supply chain complexities after the COVID-19 pandemic, weight and cost reduction are required to innovate, or sustainability is mission critical, more and more industries around the globe–from aerospace to automotive to life sciences and beyond–have shifted toward one common materials solution: High-performance, synthetic polymers.

High-performance polymers are a category of chemically-produced substances such as polyamides, polyethylene, Teflon, and synthetic rubber. They offer numerous benefits, including reduced production costs and lower weight than historical engineering materials like steel and aluminum.

However, implementing any new material into your production process takes extensive lab time to answer two key questions: How does this material change over time? And how does this material respond to specific types of stress? Proactively answering these questions before launching your product isn’t just essential to your P&L. It’s also crucial to establish parameters for safe and reliable use.

Here are three types of mechanical testing that measure polymer behavior–whether that polymer is headed through the grocery store parking lot or into low earth orbit.

Fatigue Testing

Polymers usually fail in one of two ways:

1. Over time from repeated use.
2. All at once under extreme stress.

Manufacturers almost always test number two, yet they frequently overlook number one. But plastics are actually more sensitive to failure over time. Which is why fatigue testing is critical in any high-performance product–it reproduces the conditions in which a material behaves tomorrow, next week, or in 10 years.

Fatigue testing ensures you know precisely how many “pulls” it takes to break a product or material. Specialized equipment, like Load Frame Instruments, replicates real-world conditions, using predetermined levels of force over and over until a failure occurs. This information can predict product endurance, optimize structural design, inform safety limits, or help determine durability.

Observing a material after its first or even 10th use might be relatively simple. But what about its 40,000th? Fatigue testing is the most accurate and timely way to answer that question before your product leaves R&D into the real world.

Tensile (Monotonic) Testing

What happens to a polymer under a single, powerful blow? How much force is required to break it? Tensile–or monotonic–testing gets the answer.

Data like this is necessary in its own right, but tensile testing provides even more valuable insight when combined with fatigue testing. An initial tensile test provides thresholds that can then repeat over thousands of cycles. An instrument like the ElectroForce 3200 can perform both by applying precise levels of force and then duplicating those levels – thousands or even millions of times.

That testing rigor provides a fuller understanding of a material’s weakness – from catastrophic failure to normal wear and tear. This means you will gain the insight needed to save both money and time during the pre- and post-production cycles. More importantly, you’ll also get information that can save lives.

Dynamic Mechanical Analysis (DMA)

Time and force are crucial variables in polymer research. But so is temperature. Dynamic Mechanical Analysis combines all three to measure three fundamental material properties:

• Storage modulus: The stored energy (stiffness) of a material, and how that energy returns when it’s stretched and returns back into shape.
• Loss modulus: The energy lost to heat from the materials’ viscous properties, also known as damping.
• Glass transition: The temperature range in which a material changes from its rigid “glassy” state into a more rubbery, viscous state.

From testing the modulus difference between multiple samples of one polymer, understanding how a modulus changes across a temperature range, or finding the precise temperature ranges where a material loses its structural rigidity, DMA provides robust data with a wide range of applications. Quality control, product development, and product performance just to name a few.

A complete understanding of a polymer’s behavior is not possible through any single form of mechanical testing. You might know how much force it takes to break a single sample. But what about when 50% of that force is applied 10,000 times? Or if that force is applied next to a running engine at midday?

Any one mechanical test–be it fatigue, tensile, or DMA–provides an incomplete picture. As more and more industries need to navigate the polymer development journey, only combining all three ensures they’re fully equipped to ensure they do it successfully. But with the proper tools and a rigorous testing process, polymers will continue to fuel innovation in industries worldwide.

This article explores the intricacies of PCR, challenges in processing, and techniques to verify its suitability for various applications.

From material selection and failure analysis to end-use application, Dynamic Mechanical Analysis (DMA) offers crucial polymer insights. Polymer scientists and design engineers pair DMA with fatigue testing to gain a complete view of their material’s properties and performance attributes.

Dynamic Mechanical Analysis (DMA) measures a material’s modulus, damping, and glass transition as the material is deformed under a periodic stress. DMA is particularly useful for evaluating polymeric materials that exhibit time, frequency, and temperature effects on mechanical properties because of their viscoelastic nature.¹

DMA measures two kinds of modulus: Storage modulus is a material’s stored energy or elasticity; when you pull the material, it returns the energy and moves back into shape. Loss modulus is a material’s energy that is lost to heat; this is also known as viscous or damping properties.

DMA also measures glass transition (Tg), the temperature range in which a polymer changes from a hard “glassy” material to a softer, rubbery material with more viscous properties.² This is useful information for designing processing conditions, predicting product performance, and ensuring quality control.

Difference in Modulus

DMA efficiently and accurately measures the modulus of a polymer, offering quick comparisons of different samples’ stiffness. While modulus is usually included in a material’s data sheet, running DMA tests allows polymer labs to verify their material’s modulus under specific conditions and draw accurate comparisons between samples.

Change in Modulus

DMA can measure how your material’s stiffness changes as a sample is heated or cooled from room temperature to the temperature of interest. Tracking changes in modulus is especially useful for quickly evaluating the influence of temperature on your materials, especially in a temperature range of interest which can help identify where to focus other mechanical tests such as fatigue studies.

Approaching Transitions

DMA is useful for tracking overall material properties as you approach a temperature of interest, such as an application-specific temperature range or potential failure temperatures. Even if you know that a material’s glass transition is at 145° C, how does it change up until that transition? Mapping the temperatures that impact your material beyond simple failure or transition temperatures offers a much more accurate and complete picture of material behavior.

Deeper Insights than Manufacturer’s Operating Ratings

While manufacturers offer suggested temperature ranges for use, those ranges often overlook more subtle changes that take place in the material. In the example below, the manufacturer’s operating rating is 130°. However, the material is clearly changing well below that temperature rating, meaning significant effects on strength and fatigue life are likely, but the exact effect is not possible to predict from DMA data alone.

Upon seeing the change in loss modulus well below the temperature rating, researchers were able to zero in on a temperature range where the material is changing and focus their effort in that range. They decided to perform a fatigue test at 100° C to evaluate the effect of the increased temperature on the fatigue life. Their fatigue testing data revealed that at 100° C, the material had a 90% reduction in fatigue life. DMA highlighted that the manufacturer’s rating was incomplete, and fatigue data completed the picture with a more accurate understanding of the material at “approved” temperatures.

Combining DMA and Fatigue for the Complete Picture

As the example above illustrates, DMA data can effectively inform fatigue testing to offer the complete picture of polymer performance. DMA offers deeper insights into material behavior that may be oversimplified in operating ratings and on data sheets. Learn more about fatigue testing and see the rest of the fatigue data for this sample in the TA application note “Flexural Fatigue Behavior of Woven Fiberglass Composites at Elevated Temperature.”

节省聚合物研究的时间存在多种益处，可通过不同的方式实现，包括减少操作员操作适应时间、提高研究通量以及获得准确和可重复的结果。此处的 3 种技术（流变、TGA 和 DSC）所提供的解决方案是可节省聚合物研究时间的 3 个机会。

聚合物熔体流变可用于对影响加工质量（如挤出和成型部件）的分子结构进行指纹图谱分析。根据制造工艺的不同，材料可能会在不同的时间段内经历多个温度和加工速度，因此，早期预测聚合物的熔体行为以优化加工条件至关重要。优化可能涉及将聚合物在等温条件下保持特定时间或提高温度，以提高聚合物注入模具时的流动性。

聚合物熔体流变的常用设置是平行板夹具。与测试低粘度材料（如油和液体）时常用的锥体夹具不同，平行板夹具样品内的速度梯度在外边缘处最大。这意味着仪器和数据所测得的扭矩大部分代表了该边缘的测量值。为获得准确和可重复的结果，用户必须持续去除多余的样品（称为 “修边”）以防止边缘效应。

自动修边技术消除了与用户错误和多用户不一致性相关的多种差异根源。该技术的应用可将测量的一致性、可重复性和准确性提高达 5 倍，同时可将无人值守时间增加 80%，并可将新操作员的操作适应时间降至不到 30 分钟。

阅读技术简介 – 聚合物熔体流变工作流程自动化：流变仪的自动修边

ANSI/ASTM 程序 D-2307 是估算电线绝缘寿命的常用测试。在该程序中，双绞绝缘线在高温（最高 240℃）下进行烘烤老化（长达 50 天），直到发生电压击穿。

该程序虽然有用，但非常耗时，通常需要几个月的时间，对于高稳定性材料而言尤其如此。随着越来越多的稳定的聚合物电气绝缘材料的出现，全套测试所需的时间变得过于冗长。

热重分析 (TGA) 可监测材料随温度变化的重量变化，提供了一种可替代烤箱老化的测试方案。评估一种材料的总时间不到一天，使用自动 TGA 时的人员实际操作时间更短，可进行通宵评估。

阅读完整的研究 – 通过 TGA 分解动力学估计聚合物寿命

差示扫描量热仪 (DSC) 技术是了解材料热性能和形态的关键工具。聚对苯二甲酸乙二醇酯 (PET) 是一种普遍存在的半结晶热塑性聚合物的示例。影响 PET 材料特性的关键因素之一是结晶度百分比，可通过热加工条件对结晶度百分比进行控制。

在相同的条件下同时研究 PET 样品，可实现在同等条件下对样品进行直接比较，并可确定作为热历史函数的热性能差异。并行运行样品有可能提高研究通量、减少运行时间并提高实验室的整体效率。

阅读完整的研究 – 使用 X3 DSC 进行半结晶热塑性分析

欲了解更多信息或提交产品查询，请访问我们的联系页面。

成功的增材制造产品取决于材料的特性和行为。流变可为安全、高效和可重现的聚合物制造提供有价值的信息。

聚合物产品无处不在，从包装薄膜、酸奶杯到复杂的汽车零件均使用聚合物产品。尽管应用广泛，但塑料产品通常均通过相同的简单步骤进行制造：

1. 制造的起始步骤是应用聚合物基材料（通常为颗粒或粉末形式）
2. 加热材料以形成自由流动的熔体
3. 通过吹膜、注塑成型、挤出或增材制造（3D 打印）等工艺实现熔化材料的成型
4. 冷却并凝固产品

终产品的特性和物理形态在很大程度上取决于其加工过程。制造商需要深入了解他们的材料和应用，以达到预期的终产品质量。在加工过程中了解材料是可能的，但这会导致更大的材料损失和更高的生产成本。

如果在加工前以实验室规模进行材料表征，则表征会更为有效并且会提高最终的生产率。然后，制造商可根据材料的测量特性设计加工条件。

制造商和研究人员都利用流变来研究材料的变形和流动。流变可提供有关液体和固体材料的关键、精确的见解，为成功的增材制造提供信息。

虽然增材制造为高效率和独特形状产品的制造提供了新机会，但在创造完美产品的过程中仍存在多种障碍。

在增材制造过程中，聚合物被熔化到熔融状态并通过 3D 打印机的管线和喷嘴挤出。因此，聚合物必须能够自由流动，并且需要具有尽可能低的黏度。同时，聚合物必须在挤出后立即保持其形状，并且在冷却过程中不能出现变形。Waters – TA Instruments 的应用专家 Lukas Schwab 指出，3D 打印中使用的材料需要在黏度（液体流动性特征）和固体弹性之间实现精确的平衡。

3D 打印涉及通过狭窄的模具压制聚合物。可能会发生一种称为“线性膨胀”的现象，即在出模后，聚合物股线直径与成型模具直径相比略有增加。可应用流变仪检测直径变化的程度。预测和测量线性膨胀有助于制造商确保其 3D 打印产品的精度。

将回收材料用于打印产品对聚合物制造商提出了另一个挑战。废旧塑料通常含有残留添加剂、颜色和填料，它们会影响熔体的质量、可加工性及其在制造过程中的行为。因此，再生塑料的加工及其终产品可能难以预测。因此，需要对生物塑料进行详细的分析。

尽管存在这些潜在的干扰和不确定性，制造商仍然可以执行强有力的预先产品控制和质量保证。其中的关键是分析性思考的两个角度：

• 产品中使用的所有材料成分的相互作用
• 必要的工艺参数，包括温度、压力和流量

Waters 的应用和支持专家 Marco Coletti 在他的网络研讨会上解释了如何借助流变研究来优化 3D 打印和增材制造工艺。

Lukas Schwab 解释说，使用相应的功能强大的高精度流变仪可确定流变特性，这是材料表征的重要组成部分。

Waters 的应用专家表示：“特别是在应用聚合物熔体等液态物质的情况下，如果没有足够的仪器，了解和预测流变特性可能会非常耗时。” 样品行为通常会根据作用于样品上的力的大小而发生变化，这意味着“样品的流动和变形行为只能通过实验模糊地预测，或通过流变进行更为精确的测量。”

Discovery 混合流变仪 (DHR) 是用于流变的多功能分析平台。该仪器配置了最新的专利技术并且极为人性化，可以很容易地测量直接张力、变形控制以及轴向力规格。

通过应用流变仪完成流变测量。流变仪测量材料（液体或固体）在受力时的变形。应力、变形和剪切行为的结合构成了流变、材料变形科学的基础。

进行旋转流变测量时，将样品放置在两个圆板之间的圆筒中并将圆板和样品压在一起。例如，之后可按规定的速度和方向旋转其中的一个圆板。Lukas Schwab 解释说：“旋转测量是确定材料黏度的合适方法，该方法可确定如在 3D 打印中的泵送和加工能力。”

相比之下，振荡测量（两个圆板中的一个以小振幅正弦方式来回移动）可提供有关样品平衡结构的更多信息，因此更多地用于确定材料的特性。振荡测量有助于解答不同产品批次的分子量或材料在较低力量作用下的行为等问题。

通常借助流变测量法来确定材料的黏度或黏弹性，Lukas Schwab 总结道：“黏度是对内部摩擦引起的流动阻力的测量，其测量值取决于系统的微观特性，如粒径。反之，黏弹性是材料对变形力所作反应的特性的测量。就纯弹性材料而言，对其施加负载后不会耗散能量；反之，黏弹性材料由于材料变形，其应力-应变行为的效应存在一定程度的差异（滞后效应）。”

Lukas Schwab 解释说：在许多生产过程中将流变测量用作质量控制的方法，因为不良的黏弹性行为会导致材料性能不佳和变脆。黏弹性也可用于确定固体的耐久性和热机械分解行为。

测量所有必要的特性（黏度、分子量、材料行为和黏弹性）可能看起来令人生畏，但 Discovery 混合流变仪具有独特的能力，能够以行业领先的准确性和易用性提供熔融或固体聚合物材料的完整图像。

请访问我们的聚合物应用页面，以了解更多的有关可持续、高效聚合物生产的其他类型的材料分析。同时请联系 TA Instruments，与聚合物材料分析专家取得联系。

技术的发展日新月异。无论您是升级旧设备还是为您的工作台添加新技术，使用尖端仪器都一定会提高您实验室的效率和成果。新型仪器可提供更可靠的数据和更先进的功能，这对于始终立足于材料创新前沿而言至关重要。

但是，如何在升级仪器以获得最佳投资回报的同时最大限度地减少停机时间呢？以下是可让您无缝且轻松地升级实验室的 4 种方法。

用最新型号的仪器更换服务多年的老旧仪器是改善实验室结果的最简单的方法之一。更好的消息是，您可以用旧仪器换取升级折扣。

2000 年推出的 TA Instruments Q 系列热分析仪彻底革新了测量方法，Discovery 系列以其改进的测量和易用性延续了品牌传统。用户可对其 Q 系列 DSC、TGA、DMA、SDT、TMA 仪器或竞争型号仪器进行以旧换新，以节省购买新的 Discovery 系列热分析仪的费用。Discovery 系列提供无与伦比的灵敏度和准确性，可检测样品中的最小变化，并通过强大的 TRIOS 软件提供革命性的用户体验。点击此处以解更多信息并联系我们以对您的热分析仪进行以旧换新。

同样，您可以对 TA Instruments AR 流变仪或竞争型号仪器进行以旧换新，以节省购买新的 Discovery 混合流变仪的费用。升级到 DHR 实现了卓越的功能改进 – 由于 DHR 优异的扭矩灵敏度，用户可使用更少的样品测量更低的黏度和更小的应力。该仪器的混合功能是游戏规则的改变者：可在一台含集成线性 DMA 的流变仪上进行剪切流变学、黏性/剥离、拉伸黏度测量，以及张力、弯曲和压缩测量。DHR 广泛的功能和配件（包括与许多 AR 配件的兼容性）可为您实验室未来可能需要的任何测量提供保障。联系我们以了解有关流变仪以旧换新的更多信息。

除节省成本外，对您的热分析仪或流变仪进行以旧换新也非常易于操作且回报丰厚：

• 通过承接已有的历史数据和操作程序实现平稳过渡
• 使用新的“无人值守”自动进样器减少瓶颈（可在特定的热分析仪型号上使用）
• 借助专为每个用户级别的易用性而构建的 TRIOS 软件，最大限度地减少操作适应时间
• 通过可靠的结果和更高的准确性提高数据可信度
• 通过新功能和测量选项扩展实验室能力

水凝胶为三维多孔隙结构，能够吸收大量的水分。水凝胶可由聚合物、蛋白质、多肽、胶体、表面活性剂或者脂类物质产生。¹ 水凝胶具有超强的吸水能力，因此可应用于许多生物学领域，包括药物递送和组织工程。吸收水分后水凝胶的性质会发生改变，因此科学家们需要准确表征水凝胶在不同水饱和度以及在变化条件下的行为特性。

天然形成水凝胶的一个示例是胶原蛋白，它是人体主要的结构蛋白。胶原蛋白具有纤维特性，因此是构建组织结构的理想材料。胶原蛋白分子以长纤维的形式紧密排布在一起，而且某种确切的结构排布可以产生拉伸强度与钢相似但具有一定柔韧性的原纤维。

胶原蛋白非凡的结构特性和生物相容性使其成为一种使用广泛的材料，特别是用于组织工程中的基础框架材料。² 胶原蛋白是一种天然材料，其质量在不同的样品间存在差异。因此，以胶原蛋白为基础材料制造具有一致性能的产品往往存在挑战性。但是，天然起始原料所固有的差异性难题并非不可战胜，我们需要的仅仅是进行正确的材料性能测试，以预测材料在最终应用中的
行为。

在本博客中，我们将使用胶原蛋白作为对水凝胶进行表征的主要示例。但是，同样的技术也可应用于任何材料来源的任何水凝胶。

流变学是衡量液体和固体的流动和变形行为的学科，是研究如胶原蛋白等水凝胶的一个理想方法。水凝胶具有固有的粘弹性质，也就是说，它们可同时表现出粘性行为和弹性行为。动态（振荡）流变学可对这些复杂材料进行表征，并给出粘弹性的定量测量报告：

• 储能模量：使样品发生扭曲需要施加的能量
• 损耗模量：材料变形后恢复其原有形状时所损失的能量
• 损耗角正切：损耗模量与储能模量的比值，该指标用于测量水凝胶的阻尼能力

在试图了解不同水凝胶样品在交联度、玻璃化转变、异质性和分子量方面存在的差异以及这些差异如何影响最终的使用性能时，对这些粘弹性指标进行测量至关重要。1 流变仪可轻松测量粘弹性，是优化上述特性的理想工具。

另一个重要指标是屈服应力，该指标对于衡量水凝胶也很关键。很多水凝胶均为可注射性材料，而屈服应力之所以重要的原因是，该指标决定了在注射点保留水凝胶的程度。剪切响应也决定了水凝胶溶液在注射时的难易程度。

不同的胶原蛋白起始材料可以具有非常不同的物理和热学性质，研究者们需要在实际应用条件下对胶原蛋白进行详细表征，以选择用于特定用途的最佳材料。³ 流变学测试设备的快速筛选能力使得胶原蛋白的工业生产既高效又具有成本效益。