Research

This project serves to support the project partners of the Josef Ressel Center "Restex", in which various recycling strategies for blended textile fabrics, primarily polycotton (cotton-polyethylene terephthalate blended fabrics), are developed and analyzed. During their service life and especially during thermal reprocessing, the polyester chains are degraded by chemical (detergent), thermal, mechanical or hydrolytic influences. Re-granulated polyethylene terephthalate (PET) is shear-sensitive and thermally sensitive during thermoplastic reprocessing. As a result of the reduced molecular weight the melt viscosity, melt strength and mechanical properties are drastically reduced compared to virgin polyesters. Hence the reuse of the polyester in equivalent applications is limited. The services provided by the Institute of Environmental Biotechnology (Bioplastics Technology Group) include the preparation of the textiles for the subsequent separation processes of cellulose and polyester as well as the performance of extrusion trials for the production of Re-PET granulates on a laboratory and production scale. The primary aims of these tests are (i) to optimize the mechanical properties of the recovered polyesters by means of analyses and (ii) to adapt the preparation and compounding process and, if necessary, (iii) to add additives to the recovered polyesters or surface modifications of the cellulosic residues.

There have been reports of global decline in managed honey bees and wild bees around the world. The rapid dying of honey bee colonies was named “colony collapse disorder” (CCD) and has been linked to different factors. One of the factors are novel insecticides named neonicotinoids. The acute toxity and adverse effects on bees is not only limited to the parent compound, but their (intermediate) metabolites have been shown to be toxic as well. So far, partial metabolic pathways in honey bees were described for only three out of seven neonicotinoids in use. For the remaining four neonicotinoids the metabolism by honey bees is still unclear. The overall objective of this study is to elucidate the metabolism of orally administered neonicotinoids in honey bees. The specific objectives are to determine known and unknown neonicotinoid biotransformation products and their kinetics. The study will be divided into four phases. In phase I, neonicotinoids will be administered at two locations to groups of caged honey bees with a feeding solution containing a mixture of unlabeled and 13C-labeled neonicotinoids with doses up to LD50 and sampling at 8 time points. Next, the targeted compounds will be extracted with organic solvents. For untargeted analysis, an isotope assisted approach will be used with direct analysis of the extracts as to avoid loss of putative biotransformation products (Phase II). Data will be evaluated with the aid of comprehensive databases. Unknown neonicotinoid