This dataset contains the excel files with the raw data and evaluations of the experiments of the study “Investigation of Synergistic Effects of UV Radiation and Elevated Temperatures on Regenerated Cellulose Fiber-Reinforced Bio-Polyamide 5.10 Composites and the Contribution of UV Stabilizers to their Stability” which is currently in the publication process at Elsevier.

This study investigates the thermo- and photo-oxidative degradation behavior of a bio-based polyamide (PA) 5.10, both neat and 20 wt.% regenerated cellulose fiber-reinforced (RCF). In Addition, these materials were modified with two different UV stabilizers, AddWorks IBC760 (IBC), a hindered amine light stabilizer, and LUBIO UV16 (LUBIO), an UV absorber. 168 hours of storage at temperatures of 23 °C, 50 °C, 70 °C to 90 °C at 50 %rH, with and without UV exposure of 1000 W/m², revealed significant degradation effects both in neat and LUBIO-stabilized batches, including molecular chain splitting processes, embrittlement, reduction in surface polarity and pronounced yellowing. In contrast, the IBC provided superior stabilization, maintaining thermal and mechanical properties as well as color stability. RCF-reinforced PA5.10 exhibited moisture-induced plasticization, increasing ductility as well as aging-induced embrittlement at elevated temperatures. SEM imaged confirmed an increased share of fiber ruptures in the UV exposed neat RCF-composites, while IBC-stabilized specimens preserved the high amount of fiber pull-outs. Melt volume rate measurements demonstrate the reduction in molecular weight due to the thermo- and photo-oxidative degradation. A linear polynomial regression was also used to demonstrate the characteristic degradation mechanisms of polyamide. Overall, the IBC-stabilized batches show a significant stabilization effect across all tested storage conditions. These findings highlight the potential of UV-stabilized RCF-reinforced PA5.10 composites as sustainable replacements for petro-based polyamide composites in applications requiring long-term resistance to thermo- and photo-oxidative stress.

PA5.10-based composites with 20 wt.% RCF, partially including 1 wt.% of IBC or LUBIO, were produced using a ZSE 18 HPe co-rotating twin-screw extruder (Leistritz Extrusionstechnik GmbH, Nuremberg, Germany) at 200 min-1 with an 18 mm screw diameter and 40D length. The screw configuration included kneading and conveying elements with increased free volume in front of the sidefeeder, positioned at 20D, followed by conveying elements to ensure minimal shear force on the RCF. Prior to compounding, PA5.10 was dried to < 0.1% moisture using a dry air system (TORO-Systems Dry Jet Easy dry air dryer, Gfk Thomas Jakob und Robert Krämer GbR, Igensdorf, Germany) for four hours at 80 °C, while RCFs were dried at 105 °C for 24 hours in a convection oven [38]. Material dosing was controlled via gravimetric feeders (Brabender Technology GmbH & Co. KG, Duisburg, Germany). The UV stabilizers were added to the matrix material by a separate feeder at the beginning of the compounding process. Processing temperatures ranged from 245 °C in the feeding zone to 220 °C at the nozzle, with metered melt temperatures at the nozzle of 240 °C and melt pressures of 40 – 80 bar. Minimum processing temperatures were chosen to protect the RCFs from thermal degradation [34, 39]. The resulting strands were cooled with compressed air and pelletized into 3 – 4 mm granules using a Scheer SGS 25E pelletizer (Maag Germany GmbH, Grossostheim, Germany).
In this study, type 1A test specimens were produced in accordance with DIN EN ISO 527-2 using an Allrounder 320C injection molding machine from Arburg GmbH & Co. KG (Lossburg, Germany), equipped with a 25 mm screw. The six batches were pre-dried at 80 °C for four hours to reduce moisture content below 0.1 %, minimizing the residual moisture in the granules. Type 1A test specimens were manufactured for both neat and RCF-reinforced batches. Injection molding was performed using a cold runner system, with a screw rotational speed of 15 m/min. 

To investigate the effects of thermal and UV-induced aging, as well as the influence of the UV stabilizers, a total of nine storage conditions were applied. These included a non-aged reference and thermal storage at 23 °C, 50 °C, 70 °C, and 90 °C, each conducted with and without UV radiation. The non-aged specimens were sealed immediately after injection molding in aluminum composite bags to prevent exposure to ambient humidity. Storages were performed in climate chamber type 3433/18 (Feutron Klimasimulation GmbH, Langenwetzendorf, Germany) equipped with a SOL radiation module. The SOL module simulates natural sunlight with an irradiance of 1000 ± 10% W/m² over the spectral range of 305 to 2800 nm, measured at a distance of 1.0 meter from the light source. The UV exposition was applied to artificially create photo-oxidation. Each storage condition, was applied for a duration of 168 hours. Subsequently, all specimens were conditioned under standard climate according to ISO 291 (23 °C, 50 %rH) for an additional 168 hours to ensure equilibration before testing. 

The information on the respective tests carried out can be found in the corresponding Excel file under “Information”.