Heim, Hans-Peter
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Research Data Influence of Ethylene Oxide and Gamma Irradiation Sterilization Processes on the Properties of Poly-L-Lactic-Acid (PLLA) Materials [Dataset]Krug, Natalie; Heim, Hans-Peter; Zarges, Jan-ChristophResearch Data Differentiation between Hydrolytic and Thermo-Oxidative Degradation of Poly(lactic acid) and Poly(lactic acid)/Starch Composites in Warm and Humid Environments [Dataset](Universität Kassel) Goetjes, Victoria; Zarges, Jan-Christoph; Heim, Hans-PeterFor the application of poly(lactic acid) (PLA) and PLA/starch composites in technical components such as toys, it is essential to know their degradation behavior under relevant application conditions in a hydrothermal environment. For this purpose, composites made from PLA and native potato starch were produced using twin-screw extruders and then processed into test specimens, which were then subjected to various one-week ageing processes with varying temperatures (23, 50, 70, 90 °C) and humidity levels (10, 50, 75, 90%). This was followed by mechanical characterization (tensile test) and identification of degradation using Gel Permeation Chromatography (GPC), Thermogravimetric Analysis (TGA), Fourier Transform Infrared Spectroscopy (FTIR), and Nuclear Magnetic Resonance spectroscopy (NMR). With increasing temperature and humidity, there was a clear degradation of the PLA, which could be reduced or slowed down by adding 50 wt.% starch, due to increased crystallinity. Hydrolysis was identified as the main degradation mechanism for PLA and PLA/starch composites, especially above the glass transition temperature, with thermo-oxidative degradation also playing a subordinate role. Both hydrolytic degradation and thermo-oxidative degradation led to a reduction in mechanical properties such as tensile strength. In case you use the data please cite our corresponding article (https://doi.org/10.3390/ma17153683).Research Data Haptic Polymer Testing: A Method for Evidence-Based Material Perception MeasurementSchweiger, Leander; Heim, Hans-PeterResearch Data Chemical Resistance of Regenerated Cellulose Fiber-Reinforced Bio-Polyamide 5.10 [Dataset](Universität Kassel) Falkenreck, Celia Katharina; Zarges, Jan-Christoph; Heim, Hans-PeterPolyamides are known for their chemical resistance and are commonly used as matrix materials in glass fiber-reinforced composites (GFC) for automotive applications such as fuel caps and housings. To assess the potential of natural fiber-reinforced composites (NFC) as alternatives, this study investigates the chemical resistance of a bio-based polyamide (PA5.10) reinforced with regenerated cellulose fibers (RCF). Composites containing 20 wt.% RCF were produced using twin-screw extrusion, and standardized type 1A test specimens were injection molded. These were exposed to various fluids (distilled water, salt water, soap water, acid rain, rubbing alcohol, engine oil, ethanol, sodium hydroxide solution, and 2-propanol) for up to 168 hours. Subsequent analyses included tensile testing, FTIR spectroscopy, MVR, moisture measurements, and SEM imaging. Results revealed significant hydrolytic degradation, indicated by FTIR and decreased viscosity. Degradation was especially pronounced in acidic and alkaline media. A strong link was observed between increased moisture uptake and reduced mechanical properties. Chemical exposure led to notable damage in RCF composites, attributed to the moisture absorption of RCF and fiber degradation, as confirmed by SEM images. Loss of fiber-matrix adhesion further contributed to substantial declines in tensile strength and Young’s modulus. These findings highlight limitations in chemical resistance for RCF-reinforced bio-based polyamides, especially under harsh environmental conditions.
This data set consists of the measured data from the conducted experiments as well as the data analysis.
In case you use the data please cite the corresponding article. The corresponding publication is currently in publication process.Research Data Correlation of the crystalline structure, moisture content, texture and aging-induced degradation of polyamide 5.10 using wide-angle x-ray scattering analysis [Dataset](Universität Kassel) Falkenreck, Celia Katharina; Zarges, Jan-Christoph; Heim, Hans-PeterThis study provides a detailed analysis of the crystalline structure of polyamide 5.10 (PA5.10) and determines the effects of hydrothermal aging on its moisture content, crystallinity, and texture. Using wide-angle X-ray scattering (WAXS), the investigation revealed insights into both the amorphous boundary layer and the semi-crystalline core, with a Python script based on Bragg’s law enabling precise identification of crystalline phase planes. Gaussian fitting of crystalline peaks further refined the structural understanding. The effects of experimental parameters on WAXS measurements were examined to identify additional factors influencing PA5.10. Hydrothermal aging led to notable changes, including increased moisture absorption, volume expansion, enhanced crystallinity, and shifts in molecular structure and crystalline morphology. WAXS showed that moisture-induced scattering reduced intensity, which was reversible upon re-drying. Despite an increase in crystallinity observed by DSC, WAXS did not capture a corresponding shift, likely due to the combined effects of residual moisture and annealing processes. Overall, this study enhances the understanding of PA5.10's crystalline behavior under hydrothermal exposure and provides a basis for future investigations into its aging processes and structural evolution. These findings contribute to a broader understanding of the long-term degradation mechanisms and stability of bio-based polyamides under hydrothermal and humid conditions. Moreover, the insights gained are relevant for predicting material performance in moisture-sensitive applications and can inform the development of stabilization strategies for hygroscopic polymers.
This dataset consists of the measured data from the conducted experiments, python scripts as well as the data analysis.
In case you use the data please cite the corresponding article. The corresponding publication is currently in publication process.