STRUCTURAL AND MECHANICAL CHARACTERIZATION OF DEFORMED POLYMER USING CONFOCAL RAMAN MICROSCOPY AND DSC

Polymers have various interesting properties, which depend largely on their inner structure. One way to influence the macroscopic behaviour is the deformation of the polymer chains, which effects the change in microstructure. For analyzing the microstructure of non-deformed and deformed polymer materials, Raman spectroscopy as well as differential scanning calorimetry (DSC) were used. In the present study we compare the results for crystallinity measurements of deformed polymers using both methods in order to characterize the differences in micro-structure due to deformation. The study is ongoing, and we present the results of the first tests

Reprocessing of injection-molded magnetorheological elastomers based on TPE matrix

Nowadays, the magnetorheological elastomers (MREs) represent an important composite group with a wide range of applications. They are however predominantly typified by chemically cross-linked polymer matrices which makes them difficult to be reprocessed or recycled. Here, we demonstrate the concept of the MREs’ reprocessing for the first time. The thermoplastic elastomer (TPE) was adopted as a suitable matrix allowing the MRE production via injection-molding, while making them also reusable. Each processing iteration was accompanied by thermo-mechanical degradation causing the gradual TPE oxidation, decrease in the TPE molecular weight and a viscosity reduction of their melts. In the MREs, the unexpected processing-induced particle/matrix bonding was revealed, which promoted their stiffening. As a result, the magnetic field-induced particle mobility was limited decreasing the magnetorheological activity of the MREs by tens of percent per the processing cycle. We expect that the injection-molded TPE-based MREs could offer a new pathway for producing the smart engineering composites owing to the ability to be easily reprocessed. © 2019 Elsevier LtdEU Funds - OP Research, Development and Education [CZ.02.2.69/0.0/0.0/16_027/0008464]; Ministry of Education, Youth and Sports, Czech Republic; Czech Science Foundation [17-24730S]; Ministry of Education, Youth and Sports of the Czech Republic Program NPU I [LO1504

Rheological Properties of Aqueous Sodium Alginate Slurries for LTO Battery Electrodes

Rheological properties of electrode slurries have been intensively studied for manifold different combinations of active materials and binders. Standardly, solvent-based systems are under use, but a trend towards water-based electrode manufacturing is becoming more and more important. The different solvent is beneficial in terms of sustainability and process safety but is also accompanied by some disadvantages such as extraction of residual humidity and a higher complexity concerning slurry stability. Li4Ti5O12 (LTO) active material provides good long-term stability and can be processed in aqueous solutions. Combining the LTO active material with sodium alginate (SA) as a promising biobased polymer binder reveals good electrochemical properties but suffers from bad slurry stability. In this work, we present a comprehensive rheological study on material interactions in anode slurries consisting of LTO and SA, based on a complex interaction of differentially sized materials. The use of two different surfactants—namely, an anionic and non-ionic one, to enhance slurry stability, compared with surfactant-free slurry