One-Pot Process: Microwave-Assisted Keratin Extraction and Direct Electrospinning to Obtain Keratin-Based Bioplastic

• Main Authors: Elena Pulidori, Simone Micalizzi, Emilia Bramanti, Luca Bernazzani, Celia Duce, Carmelo De Maria, Francesca Montemurro, Chiara Pelosi, Aurora De Acutis, Giovanni Vozzi, Maria Rosaria Tinè
• Format: Article
• Language: English
• Published: MDPI AG 2021-09-01
• Series: International Journal of Molecular Sciences
• Subjects: keratin; keratin-based bioplastics; microwave-assisted extractions; electrospinning; circular economy; green chemistry
• Online Access: https://www.mdpi.com/1422-0067/22/17/9597

Poultry feathers are among the most abundant and polluting keratin-rich waste biomasses. In this work, we developed a one-pot microwave-assisted process for eco-friendly keratin extraction from poultry feathers followed by a direct electrospinning (ES) of the raw extract, without further purification, to obtain keratin-based bioplastics. This microwave-assisted keratin extraction (MAE) was conducted in acetic acid 70% <i>v/v</i>. The effects of extraction time, solvent/feathers ratio, and heating mode (MAE vs. conventional heating) on the extraction yield were investigated. The highest keratin yield (26 ± 1% <i>w/w</i> with respect to initial feathers) was obtained after 5 h of MAE. Waste-derived keratin were blended with gelatin to fabricate keratin-based biodegradable and biocompatible bioplastics via ES, using 3-(Glycidyloxypropyl)trimethoxysilane (GPTMS) as a cross-linking agent. A full characterization of their thermal, mechanical, and barrier properties was performed by differential scanning calorimetry, thermogravimetric analysis, uniaxial tensile tests, and water permeability measurements. Their morphology and protein structure were investigated using scanning electron microscopy and attenuated total reflection-infrared spectroscopy. All these characterizations highlighted that the properties of the keratin-based bioplastics can be modulated by changing keratin and GPTMS concentrations. These bioplastics could be applied in areas such as bio-packaging and filtration/purification membranes.