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Rigid polyurethane foam (RPUF) was prepared using hydrolyzed keratin‐modified polyol and aluminium hypophosphite as flame retardants. The effects of aluminium hypophosphite on the thermal stability and flame‐retardant properties of hydrolyzed keratin‐modified RPUFs were studied by limiting oxygen index (LOI) method, thermogravimetric analysis, pyrolysis kinetic analysis, cone analysis and smoke density analysis. The results showed that RPUF added with 7.5 wt% aluminium hypophosphite (RPUF‐HK5‐7.5AL) had the highest LOI, which was 26.1%. RPUF‐HK5‐7.5AL had the highest initial decomposition temperature, the highest T5% at a heating rate of 10 °C min−1 and the highest activation energy. In addition, RPUF‐HK5‐7.5AL possessed the lowest heat release rate at 50 kW m−2 of 125.10 kW m−2, and the lowest total heat release rate of 5.30 MJ m−2. Results indicated that RPUF‐HK5‐7.5AL had the best thermal stability and flame‐retardant properties. Scanning electron microscopy showed that hydrolyzed keratin and aluminium hypophosphite had a synergistic effect on the flame retardancy of the RPUFs. The current research results provide a useful reference for the preparation of RPUFs with good flame‐retardant properties by bio‐based modification. © 2024 Society of Industrial Chemistry. [ABSTRACT FROM AUTHOR]

Rigid polyurethane foams (RPUFs) were synthesized with hydrolyzed keratin using the "one-step method" of all-water foaming. Thermogravimetric analysis, pyrolysis kinetics analysis, cone calorimetry and smoke density (Ds) were used to investigate the effects of hydrolyzed keratin on thermal stability and combustion performance of RPUFs. The results showed that the modified RPUFs with 12.5 wt% hydrolyzed keratin (RPUF-HK5) had the lowest mass loss, the highest integrated program pyrolysis temperature, the highest activation energy, the lowest Ds (25.32 and 22.57), the highest light transmittance (64.30% and 67.46%), and total heat release (1.85 MJ/m2, 2.18 MJ/m2 and 2.92 MJ/m2), which indicated that RPUF-HK5 had better thermal stability and combustion performance. The current research results provided a useful reference for the preparation of the RPUFs with good thermal stability by bio-based modification. [ABSTRACT FROM AUTHOR]

Abstract Soy protein isolate (SPI) and hydrolyzed keratin (HK) were employed to develop compression molded films. In contrast to other studies, in which toxic chemicals or expensive methods are usually employed to hydrolyze feather keratin, in this research a novel approach was addressed. A solution of NaOH (1 M) was employed and the use of high temperatures was avoided during the process in order to obtain a simple, environmentally friendly and inexpensive method to hydrolyze feather keratin, which can be used for the development of thermoplastic films. In addition to the valorization of agro-industrial waste, the main aim of the incorporation of hydrolyzed feather keratin into film forming formulations was to increase the sulfur content and, thus, the ability to form disulphide bonds, improving the chemical and thermal stability of the resulting films. Graphical abstract Image 1 Highlights • Chicken feathers were used to extract keratin by a more sustainable method. • Incorporation of hydrolyzed keratin promoted the increase of disulphide bonds. • Addition of hydrolyzed keratin provided thermal and mechanical stability to films. [ABSTRACT FROM AUTHOR]

Hydroxyapatite (HA), a typical inorganic component of bone, is a widely utilized biomaterial for bone tissue repair and regeneration due to its excellent properties. Inspired by the recent findings on the important roles of protein in biomineralization and natural structure of fish scales, keratin was chosen as a template for modulating the assembly of HA nanocrystals. A series of HA nanocrystals with different sizes were synthesized by adjusting the concentration of partially hydrolyzed keratin. The structure and compositions of the prepared HA were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectrum, and Transmission electron microscopy (TEM). Results revealed that the size of the synthesized HA nanocrystals can be controlled by adjusting the concentration of partially hydrolyzed keratin. Specifically, the size of synthesized HA decreased from 63 ± 1.5 nm to 27 ± 0.9 nm with the increasing concentration of partially hydrolyzed keratin from 0 to 0.6g. In addition, in vitro cytocompatibility of synthesized HA nanocrystals were evaluated using the MG-63 cells.

Hydroxyapatite (HA), a typical inorganic component of bone, is a widely utilized biomaterial for bone tissue repair and regeneration due to its excellent properties. Inspired by the recent findings on the important roles of protein in biomineralization and natural structure of fish scales, keratin was chosen as a template for modulating the assembly of HA nanocrystals. A series of HA nanocrystals with different sizes were synthesized by adjusting the concentration of partially hydrolyzed keratin. The structure and compositions of the prepared HA were characterized by Fourier transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), Raman spectrum, and Transmission electron microscopy (TEM). Results revealed that the size of the synthesized HA nanocrystals can be controlled by adjusting the concentration of partially hydrolyzed keratin. Specifically, the size of synthesized HA decreased from 63 ± 1.5 nm to 27 ± 0.9 nm with the increasing concentration of partially hydrolyzed keratin from 0 to 0.6g. In addition, in vitro cytocompatibility of synthesized HA nanocrystals were evaluated using the MG-63 cells. [ABSTRACT FROM AUTHOR]

The aim of this study is the analysis and characterization of a hydrolyzed keratin-based biomaterial and its processing using electrospinning technology to develop in vitro tissue models. This biomaterial, extracted from poultry feathers, was mixed with type A porcine gelatin and cross-linked with γ-glycidyloxy-propyl-trimethoxy-silane (GPTMS) to be casted initially in the form of film and characterized in terms of swelling, contact angle, mechanical properties, and surface charge density. After these chemical-physical characterizations, electrospun nanofibers structures were manufactured and their mechanical properties were evaluated. Finally, cell response was analyzed by testing the efficacy of keratin-based structures in sustaining cell vitality and proliferation over 4 days of human epithelial, rat neuronal and human primary skin fibroblast cells.