Anti-Frothing Effect of Poultry Feathers in Bio-Based, Polycondensation-Type Thermoset Composites

Abstract

The formation of polycondensation-type thermoset resins from natural reactants such as citric and glutaric acid, as well as 1,3-propanediol and glycerol, was studied. Monitoring the mass loss by thermogravimetric analysis (TGA) allowed the rate constants of the esterification to be calculated, which were in the order of 7·10−5 s−1 for glutaric acid and approximately twice as high for citric acid. However, the combination citric acid/glycerol was previously reported to froth up at high conversions, giving rise to foams, which makes the preparation of compact engineering composites challenging. In light of this, we observed that shredded poultry feathers not only increased the conversion and the reaction rate of the combination citric acid/glycerol, but increasing the amount of feathers continuously decreased the number of visible bubbles. The addition of 20 wt% of feathers completely prevented the previously reported frothing and gave rise to compact materials that were macroscopically free of defects. Besides this, the addition of feathers also improved the fire-retardant properties. The tensile properties of the first specimens are still rather low (σ = 11.6 N/mm2, E = 750 N/mm2), but the addition of poultry feathers opens a new path for green thermoset resins.

Poultry Feather Waste as Bio-Based Cross-Linking Additive for Ethylene Propylene Diene Rubber

“…Moreover, keratin is expected to improve the fire behaviour such as flammability, combustibility, and burning rate. Similar effects of keratin were recently shown for keratin-impregnated wood fibre boards [13] and for keratin-fibre containing thermosets [14].…”

Protein Hydrolysates from Biogenic Waste as an Ecological Flame Retarder and Binder for Fiberboards

“…This is despite the fact that keratin has some remarkable thermal properties such as a high decomposition temperature. In this context, we have also recently shown the beneficial effects of shredded poultry feathers on the thermal stability of biobased, polycondensation-type thermoset composites . Moreover, keratin does not burnhence, keratin waste cannot be disposed of by incinerationand as a result, wool keratin was tested as flame-retardant coating on cotton and poultry feathers in polypropylene. , …”

“…In this context, we have also recently shown the beneficial effects of shredded poultry feathers on the thermal stability of biobased, polycondensation-type thermoset composites. 8 waste cannot be disposed of by incinerationand as a result, wool keratin was tested as flame-retardant coating on cotton 9 and poultry feathers in polypropylene. 10,11 Developing this property of keratin further led us to explore methods to transform keratin waste into flame-retardant impregnations for wood building materials.…”

Autogenous Cross-Linking of Recycled Keratin from Poultry-Feather Waste to Hydrogels for Plant-Growth Media

“…Besides that, the addition of plasticisers, such as water and/or glycerol, allows ground feathers to be processed by standard thermoplastic equipment [ 12 , 13 , 14 ]. The sorption properties of feathers were successfully used to prevent the previously observed frothing of bio-based polycondensation-type thermosets and at the same time accelerate the polycondensation reaction [ 15 ]. Some research focuses on the application of feathers and feather meal as nitrogen fertilizer [ 16 , 17 ].…”