Bioplastics research is currently challenged by high material prices and limited availability of biopolymers. For state-of-the-art compounding using a twin-screw extruder, even on lab-scale, large quantities of material are required. Poly(3-hydroxy-buthyrate) and its copolymers such as PHBV are promising biopolymers but are prone to degradation. The stabilizers used must also be biobased to ensure the sustainability of the material. In this study, a new material-saving process for the compounding of biocomposites was evaluated to investigate the potential of biogenic by-products from the winemaking industry to improve the stability of biopolyesters. Formulations based on PHBV powder and two different varieties of pulverized wine grape pomace with filler contents up to 10 wt.-% were prepared. The materials were processed on a modified miniaturized single-screw extruder with an L/D ratio of 15 equipped with a mixing screw and compared to a lab-scale twin-screw extruder with an L/D ratio of 44. Both extruders have screw diameters of 20 mm. Thermal and rheological properties of the compounded material were determined using standard polymer analyzing techniques such as GPC, MFR, DSC, TGA and OIT. The mixing quality of both extruder types was evaluated by light microscopy imaging. The results show that a miniaturized single-screw extruder represents an efficient alternative for research purposes, but minor differences in the dominant degradation mechanisms during processing must be considered for data evaluation. Especially for small quantities and frequent material changes, the miniaturized single-screw extruder is a beneficial option, reducing the limits of bioplastics research and contributing to its progress. Thermal analysis revealed that the wine-derived biogenic by-products act as antioxidant stabilizers preventing thermo-oxidative degradation of PHBV, representing sustainable biobased alternatives to synthetic stabilizers.

The surface topography of biodegradable polymer foils is modified by mechanical imprinting on a submillimeter length scale. The created patterns strongly influence the wetting behavior and allow the preparation of hydrophobic surfaces with controlled solid-liquid interaction. A detailed analysis of anisotropic surface patterns reveals that the observed effect arises from a combination of topographical and compositional changes that are introduced to the surface. As a main result it is found that an individual combination of material and structure is required for the production of water-repellent biopolymer foils that are highly attractive for packaging applications.

Linear low-density polyethylene (LLDPE) crosslinks under irradiation in the range of up to 250 kGy. Crosslinking leads to better chemical and thermal resistance but causes reduction in mechanical performance. To counter this reduction, compounds of LLDPE with thermoplastic elastomers (TPV) were made. Specimens were irradiated with doses reaching from 99 to 231 kGy. Gel content shows a decrease of around 12% for compounds with 20 wt% of TPV compared to pure LLDPE. It is also found that compounds containing 10 wt% TPV experience a 4% higher gel content than predicted. For higher amounts of TPV elongation at break increases from 689% for pure LLDPE to 769% and tensile strength decreases from 31.9 to 30.5 MPa. Under irradiation, a trend to lower elongations and tensile strengths is observed. Elongation at break decreased around 200% and tensile strength around 5 MPa under irradiation. Thermal analysis of TPV showed that while the melting temperature decreases, its crystallinity first rises for doses up to 165 kGy before decreasing. Infrared spectroscopy was used to identify changes in the chemical structure, where evidence of surface oxidation under irradiation is found for all compounds with LLDPE.

The insect repellent ethyl butylacetylaminopropionate (IR3535) was used as a functional additive for poly (l-lactic acid) (PLLA) to modify its structure and mechanical properties and achieve insect repellency. PLLA/IR3535 mixtures at various compositions were prepared via melt extrusion. In the analyzed composition range of 0 to 23 m% IR3535, PLLA and IR3535 were miscible at the length scale represented by the glass transition temperature. Addition of IR3535 resulted in a significant decrease in the glass transition temperature of PLLA, as well as in the elastic modulus, indicating its efficiency as a plasticizer. All mixtures were amorphous after extrusion, though PLLA/IR3535 extrudates with an IR3535 content between 18 and 23 m% crystallized during long-term storage at ambient temperature, due to their low glass transition temperature. Quantification of the release of IR3535 into the environment by thermogravimetric analysis at different temperatures between 50 and 100 °C allowed the estimation of the evaporation rate at lower temperatures, suggesting an extremely low release rate with a time constant of the order of magnitude of 1–2 years at body temperature.

Verpackungen für Lebensmittel sind in Deutschland eine der größten Anwendungs­gebiete für die Kunststoffverarbeitung. Der massenhafte Verbrauch von Lebensmittelverpackungen aus konventionellem Kunststoff führt jedoch dazu, dass die heutigen gesellschaftlichen Anforderungen in Bezug auf eine reduziere Umweltbelastung der Produkte nicht mehr erfüllt werden können. Konsumenten legen verstärkt Wert auf Nachhaltigkeitsaspekte bezüglich der Verpackungsmaterialien, sodass sich die Entwicklung von Produkten und Verpackungen neugestaltet. Es ist ein Trend erkennbar, bei dem konventionelle Kunststoffe zunehmend durch Biokunststoffe ersetzt werden.

Da die meisten Studien zu Biokunststoffen bislang vor allem deren technischen Grundlagen betrachten, bleiben die Anforderungen und Wünsche der Endverbraucher bei diesen Analysen unberücksichtigt. Um die Nachfrage nach Biokunststoffen schrittweise erhöhen zu können, ist aus diesem Grund eine Erforschung der gesellschaftlichen Akzeptanz unabdingbar. An dieser Stelle setzt die vorliegende Studie an. Sie untersucht den derzeitigen Wissensstand der Konsumenten hinsichtlich der Biokunststoffe und versucht Ansatzpunkte für eine Akzeptanzsteigerung als Lebensmittelverpackung zu identifizieren. Die Auswertungen basieren auf einem Sample von 505 vollständigen und inhaltlich überprüften Interviews.

Durchgeführt wurde die Studie im Rahmen einer Kooperation der Forschungsgruppe „Empirical Research & User Experience“ (ERUX) des Instituts für Informationssysteme (iisys) und des Instituts für angewandte Biopolymerforschung (ibp) der Hochschule Hof.

AccessMM führt vollkommen ergebnisoffene Erhebungen durch, die keinen Interessengruppen oder Parteien verpflichtet sind, um einen möglichst ungefilterten Einblick in die Meinungswelt der verschiedenen Bevölkerungsgruppen zu ermöglichen.