3D Characterization of Materials: a Key Enabler in Material Development

Abstract

The aim of new material development is often to achieve enhanced and reliable performance, and to provide higher customer flexibility, at a lower cost. Characterization of the structure and morphology of those materials is critically important for the optimization of conversion process conditions, and subsequently improve the properties of the materials themselves. MicroComputed Tomography technology (µCT) allows quantitative 3D micro-analysis of a wide range of materials, enabling nondestructive characterization of structure and morphology from sub-micrometric to macroscopic scales. This presentation will include discussion of three SABIC research examples where µCT was a crucial supporting technique for new material development. PVC is a commodity polymer widely used in building & construction, flexible tubing, food packaging, and medical implants. The suspension process used for 95% of the world PVC production leads to the formation of porous powder particles. The porosity is an important aspect of the product properties as it strongly influences the heat transfer efficiency preventing degradation, the free monomer removal required in most applications, and the ability of plasticizer penetration that is essential to processability and molding. The control over process parameters is therefore essential to produce a material suitable for different applications. In the study presented, the particle size and porosity is assessed as a function of the process conditions. (or: This study describes investigation of particle size and porosity and their relationship to process conditions. Foam is a type of polymer material which finds applications in many industrial segments, including packaging, mass transportation, consumer electronics and automotive. Foam combines interesting lightweight solutions with unique mechanical performance. However, the material performance is strongly influenced by the foam structure, including cell volume and wall thickness, which ultimately result from the processing conditions. The 3D characterization of foam morphology by µCT is particularly well suited to guide the optimization of process conditions and improve material performance , especially impact and compression properties. Finally, technology trends in material development include the development of organic or organic hybrid materials such as polymeric fiber reinforcement of a polymer matrix. Not only are the mechanical properties enhanced but further functionality can be added to the material, such as anti-dripping characteristics which are critical to obtain high FR performance. However, the fibrillation efficiency strongly depends on the processing conditions, which leads to challenges in the robustness of the process and the performance reliability of the material. The characterization of the morphology of such materials remains challenging in terms of spatial resolution and contrast generation. A microscopic approach combining µCT and SEM is developed, providing new insights on the formation of a 3D network of nano-fibrils. The 3D characterization of polymer materials by X-ray micro-Computed Tomography has proven to be a useful tool allowing further understanding the material process-structure-properties relationship.