Material Analysis of Composites
How do leading labs use material analysis to enhance composites?
Morgan Ulrich | Ogochukwu Onepe
September 18, 2023
We expect a lot from our composites: rocket materials need to endure the heat of takeoff, wind turbines must withstand high wind gusts, and sneakers are expected to be durable and supportive on long runs. How do experts develop composites tailored to such specific uses and verify their properties?
Composites are composed of two or more materials that are bonded together but remain distinct at the macroscopic or microscopic scale within the finished structure. The resulting composite offers different properties than any single material. Material scientists are thus empowered to optimize composite formulations for specific applications, but only with ample testing to verify material properties first.
Composite developers meet today’s high demands for lightweight, reliable products using cutting-edge analytical technologies. They address critical performance attributes expected by customers, including strength, heat resistance, adhesion, and durability by first characterizing materials and product prototypes.
How do composite scientists in labs around the world use material analysis to enhance their products? Here are the top material science techniques, plus real research examples of how they are used to test composites across diverse applications and industries:
Differential Scanning Calorimeters
Differential Scanning Calorimeters (DSC) measure temperatures and heat flows associated with thermal transitions in a material. DSC quantifies key metrics like composites’ glass transition temperature (Tg), gel time, and cure time.
Professor Mohamed Rady used a DSC at the University of Bordeaux to support his research of granular composites’ phase changes.1 He specifically looked at melting and solidification, devising a simple procedure to obtain accurate results from his DSC.
Researchers Rivière, Caussé, Lonjon, Dantras, and Lacabanne in the CIRIMAT laboratory at Paul Sabatier University used modulated DSC to study the effect of adding silver nanoparticles to a polymer (Polyetheretherketone) matrix.2 Accurate thermal conductivity and specific heat measurements allowed them to understand the mechanisms of thermal transport in the material. Their data can be used to optimize the blend of materials to form composites for specific applications.
TA Instruments’ Discovery DSC line is equipped with patented Tzero™ DSC technology for more accurate heat flow measurements with improvements in baseline flatness, transition resolution and sensitivity. Modulated® DSC (MDSC®) experiments are both faster and more accurate on a TA DSC. For even more productivity, the Multi-Sample X3 DSC uniquely measures heat flow in up to three samples simultaneously.
Rheology
Rheology is the study of flow and deformation of materials. Deformation and flow are referred to as strain and strain rate, respectively, and indicate the distance over which a body moves under the influence of an external force, or stress.
For example, Professor Ogah at Ebonyi State University used a rheometer to measure the effects of fillers and additives on processing of wood plastic composites.3 Ogah processed natural fibers with thermoplastic polymers as matrix materials, creating natural fiber composites. He then analyzed how different fiber types, contents, particle sizes and shapes influenced the final composites’ rheological properties on a TA Instruments Discovery Hybrid Rheometer.
Rheometers are uniquely capable of measuring viscosity as well as viscoelasticity. TA Instruments’ Discovery Hybrid Rheometer also helps users easily identify differences in microstructure that cannot be investigated on viscometers or capillary rheometers. These measurements are especially useful when investigating how composite materials interact at the microscopic level.
Mechanical Analysis
Mechanical testing helps researchers either characterize a material’s mechanical properties or determine a structure’s response to a specific force. Composites developers quantify the failure, fatigue, shear, or creep of their materials and use this information to design better products for specific applications.
Garces and Ayranci from the University of Alberta developed a new approach to manufacture and activate a shape memory polymer composite (SMPC) through resistive heating using extrusion based additive manufacturing.4 They used a TA Instruments ElectroForce thermal conditioned tensile tester to evaluate the effect of deformation on SMPC under specific processing conditions. Their research enables others to successfully manufacture SMPC with their technique for broad applications like “biomedical stents, sports equipment, and unmanned air vehicles (UAVs).”
Whether they are developing sturdy construction materials or biocompatible bone replacements, leading labs around the world rely on ElectroForce mechanical test instruments to verify composites’ mechanical properties. The ElectroForce load frames cover a broad range of applied forces, while the Multi-Specimen Fatigue Instrument can accelerate fatigue studies for up to 16 samples at once.
How should I test my composites?
While these research examples illustrate some of the possibilities, there are countless instruments and techniques to analyze every material property of your composites. Explore today’s leading technology on our composites page, and see which instruments match your needs in composites design and processing.
Still unsure of the best technique for your lab? Contact TA Instruments and our composites experts will be happy to point you in the right direction.
References:
- Rady, M. (2009). Study of phase changing characteristics of granular composites using differential scanning calorimetry. Energy Conversion and Management, 50(5), 1210–1217. https://doi.org/10.1016/j.enconman.2009.01.030
- Rivière, L., Caussé, N., Lonjon, A., Dantras, E., & Lacabanne, C. (2016). Specific heat capacity and thermal conductivity of PEEK/Ag nanoparticles composites determined by Modulated-Temperature Differential Scanning Calorimetry. Polymer Degradation and Stability, 127, 98–104. https://doi.org/10.1016/j.polymdegradstab.2015.11.015
- Ogah, O. A. (2017). Rheological properties of natural fiber polymer composites. MOJ Polymer Science, 1(4). https://doi.org/10.15406/mojps.2017.01.00022
- Garces, I., & Ayranci, C. (2018). A view into additive manufactured electro-active reinforced smart composite structures. Manufacturing Letters, 16, 1–5. https://doi.org/10.1016/j.mfglet.2018.02.008
Other Resources
- Application Note – Stress/Strain Evaluation of Fibers Using TMA
- Application Note – Characterization of the Degree of Cure of Thermosetting Resins by DSC
- Application Note – Using an ARES Rheometer to investigate the β-relaxation change of graphene poly(ethyl methacrylate) nanocomposite
- Application Note – Flexural Fatigue Behavior of Woven Fiberglass Composites at Elevated Temperature
- Webinar – Thermal, Rheological and Mechanical Characterizations of Thermosets