Overview

New product design is expedited by gathering product performance metrics early in the compound development process. These key metrics link to final product performance and answer common questions: How will my product perform in its final application? Is performance guaranteed over the lifetime of the product? Predicting mechanical rigidity, suitability to end-use environmental conditions, and long-term stability empower a compound developer to filter for leading candidates before progressing to expensive pilot and larger scale trials. In this talk, we will introduce several techniques to characterize cured rubber products and link these measurements to final product performance. Some topics will include:

•  Characterizing damping properties and modulus values with dynamic mechanical analysis (DMA)
•  Measuring fatigue and heat build-up testing of rubber compounds
•  Performance in corrosive and pressurized environments with thermal gravimetric analysis (HP-TGA)

About The Speaker

Sadegh Behdad is an Applications Engineer at TA Instruments, supporting ElectroForce product line. Sadegh has a PhD in Materials Science and Engineering from Florida International University. He earned his BSc and Masters in Polymer Engineering from Amirkabir University of Technology. Prior to joining TA Instruments, Sadegh worked as a Sr. Materials Scientist at Magic Leap. At Magic Leap, he supported material design and development teams on selection of material candidates and testing various materials and components for wearable virtual retinal display applications.

Overview

Have you experienced manufacturing performance differences between batches of materials, despite seeing no difference in specifications or cure data? Do you want to reduce scrap, improve processing efficiencies, and minimize variability in your manufacturing process? Join us as we adventure beyond the cure curve and look at additional testing methods to correlate material characteristics of rubber compounds with processing behavior and production success. Some key areas of interest include:

•  Verifying quality of mix
•  Optimizing mold filling processes
•  Troubleshooting extrusion issues

We will look at characterizing material behavior at key steps in the manufacturing process and using these measurements as leading indicators for production success. This allows process engineers to select suitable materials for manufacture or adjust manufacturing processes to accommodate variations in product behavior.

About The Speaker

Alina Latshaw, Ph.D. is the Product Specialist for the Rubber Testing product line at TA Instruments. Alina earned her doctorate degree in Chemical Engineering from North Carolina State University. She joined TA in 2013 as an applications engineer specializing in rheology and dynamic mechanical analysis techniques. As part of the product management team, Alina actively collaborates with customers on providing testing solutions for rubber and elastomer applications ranging from elastomer characterization, compound processing challenges, vulcanization testing, and cured rubber product performance.

Overview

Liquid-crystal elastomers (LCEs) uniquely combine molecular ordering with entropic elasticity. The result is a class of anisotropic elastomers with remarkable properties spanning stimuli responsive actuation to exceptional dissipation of mechanical energy.

Our group has recently developed a range of photopolymerizable LCE resins and inks which we 3D print using direct ink writing (DIW) and digital light processing (DLP) technologies. The combination of our chemistries and these 3D printing technologies allows facile production of some of the largest LCE devices ever produced – on a scale finally suitable for real-world applications such as spinal implants and football helmets.

In this webinar, we will briefly introduce LCEs and our 3D printing methods. Next, we will demonstrate our methods and instrumentation that have enabled our fundamental characterization of these exceptional materials. To measure the rate-dependence of DLP-printed LCE lattices, we used compression testing with strain rates ranging from 0.21 to 220 % s-1 and compared the changes in strain energy density and peak stresses with lattices printed from traditional elastomers. With anisotropic DIW-printed LCE devices we studied the dependence of quasi-static (modulus, strain energy density) and dynamic (dynamic modulus and tan delta between 0.1 – 100 Hz) mechanical properties on loading direction. Additionally, using dynamic testing we studied the long-term performance of a semi-crystalling LCE 3D printed spinal device. By subjecting prototype devices to 1 M compressive cycles under physiological conditions we measured the change in mechanical properties and demonstrated our device’s fatigue resistance.

Overall, this webinar covers a range of quasi-static and dynamic mechanical testing methods which we perform using the ElectroForce 3200 instrument to characterize these highly complex and fascinating materials.

About The Speaker

Dr. Chris Yakacki received his Ph.D. in mechanical engineering at the University of Colorado Boulder in 2007. During his graduate studies, he helped co-found Medshape, Inc. – a university-based startup focused on developing novel shape-memory devices. Dr. Yakacki worked as the principal scientist at Medshape from 2007-2011, during which time he helped clear the first shape-memory polymer devices through the USFDA. This includes the morphix suture anchor and exoshape anterior cruciate ligament (ACL) fixation device. He returned to academia in 2012 and joined the faculty at the University of Colorado Denver. He received the prestigious NSF Career Award to investigate liquid-crystal elastomers for biomedical applications. He has published over 50 peer-reviewed publications and raised over $2M in federally funded research. He is dedicated to once again translating his research from the university into the marketplace with Impressio – another university-based startup now focused on commercializing liquid-crystal elastomers.

Dr. Devesh Mistry interests lie in the fundamental physics behind the mechanical properties of anisotropic and functionalised polymers. I completed my PhD in 2018 in the School of Physics and Astronomy at the University of Leeds, UK. Supervised by Professor Helen Gleeson, my PhD focused on unresolved inconsistencies in our knowledge of LCE mechanical behaviours. In this process I discovered the inherent negative Poisson’s ratio (auxetic) behaviour of LCEs.

Following my PhD, I joined Prof. Chris Yakacki’s group at the University of Colorado Denver as a postdoctoral fellow – supported by a Lindemann Trust Fellowship. Here my research has focused on using 3D printing to understand the role of order and disorder in the exceptional dissipative properties of LCEs.

Nicholas Traugutt, a PhD candidate in Mechanical Engineering at the University of Colorado Denver under the tutelage of Prof. Chris Yakacki. My research focuses on how to tailor bulk liquid crystal elastomer (LCE) structures across different length scales (e.g. meso, micro, and macro) to better dissipate mechanical energy. In the course of my research, I have discovered several different molding and manufacturing techniques through the use of additive manufacturing as well as helping to improve synthetic methods for the thiol-acrylate LCE chemistry. One of my greatest achievements to date includes creating a scalable and tailorable method to use digital light processing to 3D print LCE structures that would otherwise be difficult to impossible to fabricate.

In my downtime on campus from researching LCEs, I am often tinkering with 3D printers. My knowledge and abilities with 3D printing led to an opportunity to work as a consultant for 3D printing PEEK, and I have success with 3D printing other engineering polymers such as PPSU.

I currently have six peer-reviewed papers, including a recent publication in Advanced Materials for DLP printing LCEs.

Overview

New product design is expedited by gathering product performance metrics early in the compound development process. These key metrics link to final product performance and answer common questions: How will my product perform in its final application? Is performance guaranteed over the lifetime of the product? Predicting mechanical rigidity, suitability to end-use environmental conditions, and long-term stability empower a compound developer to filter for leading candidates before progressing to expensive pilot and larger scale trials. In this talk, we will introduce several techniques to characterize cured rubber products and link these measurements to final product performance. Some topics will include:

• Characterizing damping properties and modulus values with dynamic mechanical analysis (DMA)
• Measuring fatigue and heat build-up testing of rubber compounds
• Performance in corrosive and pressurized environments with thermal gravimetric analysis (HP-TGA)

About The Speaker

Sadegh Behdad is an Applications Engineer at TA Instruments, supporting ElectroForce product line. Sadegh has a PhD in Materials Science and Engineering from Florida International University. He earned his BSc and Masters in Polymer Engineering from Amirkabir University of Technology. Prior to joining TA Instruments, Sadegh worked as a Sr. Materials Scientist at Magic Leap. At Magic Leap, he supported material design and development teams on selection of material candidates and testing various materials and components for wearable virtual retinal display applications.

Overview

Have you experienced manufacturing performance differences between batches of materials, despite seeing no difference in specifications or cure data? Do you want to reduce scrap, improve processing efficiencies, and minimize variability in your manufacturing process? Join us as we adventure beyond the cure curve and look at additional testing methods to correlate material characteristics of rubber compounds with processing behavior and production success. Some key areas of interest include:

• Verifying quality of mix
• Optimizing mold filling processes
• Troubleshooting extrusion issues

We will look at characterizing material behavior at key steps in the manufacturing process and using these measurements as leading indicators for production success. This allows process engineers to select suitable materials for manufacture or adjust manufacturing processes to accommodate variations in product behavior.

About The Speaker

Alina Latshaw, Ph.D. is the Product Specialist for the Rubber Testing product line at TA Instruments. Alina earned her doctorate degree in Chemical Engineering from North Carolina State University. She joined TA in 2013 as an applications engineer specializing in rheology and dynamic mechanical analysis techniques. As part of the product management team, Alina actively collaborates with customers on providing testing solutions for rubber and elastomer applications ranging from elastomer characterization, compound processing challenges, vulcanization testing, and cured rubber product performance.

Overview

The polymer used in a compound recipe is critical to compound processing behavior and final product performance, yet polymer characterization is an under-utilized technique in the rubber industry. Traditionally, the rheological behavior of the raw polymer is characterized using Mooney viscosity, which provides limited information. The Rubber Process Analyzer (RPA) can better characterize the viscoelastic behavior of polymers, specifically providing insight into the average molecular weight, molecular weight distribution, and presence of branching. These key polymer characteristics are critical to the mixing, processing, and final performance of a rubber compound. Complete characterization of a polymer early in the process can prevent costly processing issues downstream, minimize variability, and reduce scrap.

About The Speaker

Sarah Cotts is an Applications Engineer at TA Instruments in the US Eastern region. She supports the Rheology, DMA and Rubber testing instruments, working directly with customers across a wide range of industries. She earned a B.Sc. in Chemistry from the College of William and Mary. Prior to joining TA, Sarah worked as an Applications Chemist at Sartomer, developing materials for inks, coatings, adhesives and other industrial applications. She joined TA Instruments in 2013 as part of the Applications Lab.