Kategorie: ‘Kompositmaterial’
Anouncement: Polymer Blends & Eurofillers
We are pleased to announce that two exciting presentations from our working group have been accepted at Polymer Blends & Eurofillers 2025 in Lyon from January 27 to 30, 2025:
Paul Marten
Development and Characterization of a Composite Material based on Polylactic Acid, Chitin, and Lecithin
and
Fabian Weitenhagen
Sustainable Biopolymer Composites Using Recycling Cellulose from Wastepaper
Take the opportunity to learn about the latest results from the working group and to talk directly to the members.
Completed Master Thesis
We would like to congratulate Sandra Czypionka on successfully completing her Master’s degree in Chemistry. The title of her Master’s thesis is: ‘Comparison of methods for determining the biodegradability of sustainable polymer composites’.
WTA-Days 2024
We were represented with a total of four lectures at the WTA Days 2024, 14-16 March 2024 in Brno, Czech Republic.
Prof Weichold presented a lecture entitled ‘Alkaline hydrogels as multifunctional repair materials’. From the field of bio-based construction materials, Fabian Weitenhagen gave a presentation on ‘Renewable Polyester Resin Systems for Sustainable Construction Materials’, Paul Marten gave a presentation on ‘Chitosan as a Key Component in the Production of Sustainable Acrylic Glass-Wood Laminates’ and Nils Münstermann gave a presentation on ‘Chitosan as an Eco-Friendly Binder for High-Strength Fibreboards in Sustainable Construction’.
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 project:Recycled foams
A project for the development of mechanically stable foams was approved retroactively to 1 November. The project builds on the materials described in Appl. Sci. 2020 described materials. In addition, the effect of fillers made from recycled materials will be tested. The project is supervised by Fabian Weitenhagen.
(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 PhD Student
Fabian Weitenhagen joined our team in the field of bio-based building materials in December. He is continuing his research into bio-based polycondensation resins and is building on the results of previous work. He is also developing innovative bio-based composites to promote sustainable solutions for the construction industry.
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
