Kategorie: ‘Keratin’
New PhD Student
We have welcomed Lena Schmitz to the bio-based building materials department in July. In her dissertation, she is investigating the properties and potential applications of the fibre protein keratin, which is obtained from sheep’s wool, feathers, hair and hooves, among other things. She is trying to recycle these waste products sensibly and research environmentally friendly, resource-saving and sustainable materials for the construction industry. We wish her every success with her research and welcome her to the working group.
Completed Master Thesis
We would like to congratulate Lena Schmitz on successfully completing her Master’s degree in Chemistry. The title of her Master’s thesis is: ‘The influence of additives on the mechanical properties of thermoplastic biocomposites made from hydrolysed keratins’.
3rd ICSTI
Prof. Weichold gave an online lecture entitled ‘The potential of keratin as renewable resource’ at the 3rd International Conference on Science Technology & Innovation (3rd ICSTI), 11 August 2023 in Chiang Mai, Thailand.
IPC2023
At the 13th Society of Polymer Science Japan (SPSJ) International Polymer Conferences (IPC2023), 18-21 July 2023 in Sapporo, Japan, we were represented with two presentations:
Prof Weichold
Firefighting with feathers
Fabian Weitenhagen
Development of bio-based thermosetting polyester resins
Joint publication:
Metal complexes with keratin ligands
In collaboration with the research group led by Prof Panwad Sillapawattana from Maejo University, Chiang Mai, Thailand, complexes of Fe3+, Cu2+, Zn2+ and Ag+ with keratin ligands were produced and possibilities for application in the biomedical field were investigated. In particular, keratin hydrolysates with low molecular weight show higher metal adsorption. The overall results suggest that the specific properties of the complexes, including heat resistance, antibacterial activity and low cytotoxicity, are desirable for medical textiles.
A. K. Aldred, P. Klungsupya, W. Charerntantanakul, O. Weichold, P. Sillapawattana
Preparation of Keratin‑Metal Complexes Derived from Different Treatments of Chicken Feather Waste
Waste Biomass Valor. 2024, 15, 115. https://doi.org/10.1007/s12649-023-02154-z
New publication:
Springs replace carbon black in rubber
Most elastomers (‘rubber’) used today are based on sulphur as a cross-linking agent and carbon black from fossil raw materials to change the mechanical properties. Here we show that natural keratin, e.g. from poultry feathers, can be a very promising substitute for both. Feathers are not only tough, but also contain a relevant amount of sulphur in the form of disulphide bridges. These can be activated under vulcanisation conditions and then covalently bind to EPDM rubber to form a cross-linked network. The presence of spring waste increases the tensile and compressive strength as well as the hardness and reduces the rebound resilience. Due to their high nitrogen content of approximately 17%, the springs also improve the thermal stability of the composite, shifting the main degradation step from 400°C to 470°C and significantly slowing down decomposition. As elastomers are a large market and springs in particular are a voluminous waste, the combination of the two offers enormous ecological and economic prospects.
M. Brenner, O. Weichold
Poultry Feather Waste as Bio-Based Cross-Linking Additive for Ethylene Propylene Diene Rubber
Polymers 2021, 13, 3908. https://doi.org/10.3390/polym13223908
New publication:
Feathers let plants grow
The global rise in temperature is leading to an increasing spread of semi-arid and arid regions and is accompanied by a deterioration of agricultural land. Polymers can help in many ways, but must not become a burden on the environment. In this context, we present here a method by which poultry feathers, representative of keratin waste in general, can be converted into hydrogels for use as a plant growth medium. Naturally cross-linked hydrogels are formed from suitably produced, aqueous keratin solutions during evaporation. The cress germination test showed that the gel contains no toxic substances and adheres strongly to the roots. This protects the plants from drought stress as long as the gel still contains moisture.
M. Brenner, O. Weichold
Autogenous Cross-Linking of Recycled Keratin from Poultry-Feather Waste to Hydrogels for Plant-Growth Media
Polymers 2021, 13, 3581. https://doi.org/10.3390/polym13203581
(Deutsch) Neue Veröffentlichung:
Federn als Bindemittel und Flammschutz
The increasing demand for sustainable building materials requires alternative flame retardants that are more sustainable than those used to date. In this context, we present our first results with recycled poultry feather waste for the production of flame-retardant fibreboards. Impregnated wood fibres show a significantly reduced decomposition rate and decomposition temperatures that are approx. 50 °C higher. In addition, decomposition takes place gradually and not immediately as with untreated wood. With a total protein content of approx. 10 % by weight, the boards produced using the wet process are self-extinguishing and do not smoulder. In the three-point bending test, these fibreboards failed at 15 N/mm2, the limit value required by DIN EN 622 for commercially available, formaldehyde-bonded MBH fibreboards. This shows that the recycled feather residues not only have an impressive flame-retardant effect, but can also be used as a fully-fledged binder for a new generation of ecological fibreboards. As these boards are based exclusively on natural materials, they can be shredded and composted at the end of their life cycle.
The article was selected by the Journal for the cover of issue 5(50).
M. Brenner, O. Weichold
Protein Hydrolysates from Biogenic Waste as an Ecological Flame Retarder and Binder for Fiberboards
ACS Omega 2020, 5, 32227−32233. https://dx.doi.org/10.1021/acsomega.0c03819
New publication:
Duroplasts with a difference
Nature avoids highly reactive functional groups, such as isocyanate and epoxy, by using highly specialised enzymes as catalysts in condensation reactions. Consequently, bio-based raw materials require in vitro reaction conditions that are often difficult to reconcile with the requirements for thermoset resins. In addition, condensation reactions release small molecules (often water), which leads to the formation of foams under standard reaction conditions. It would therefore appear that natural building blocks would not be suitable for the production of thermosetting resins.
We show here that the addition of chopped feathers prevents the previously reported foaming of highly cross-linked combinations such as citric acid/glycerol, increases conversion and improves flame retardant properties.
M. Brenner, C. Popescu, O. Weichold
Anti-Frothing E ffect of Poultry Feathers in Bio-Based, Polycondensation-Type Thermoset Composites
Appl. Sci. 2020, 10, 2150; https://doi:10.3390/app10062150
