Borate chemistry inspired by cell walls converts soy protein into high-strength, antibacterial, flame-retardant adhesive

Abstract

Borate chemically cross-linked soy protein to prepare high-strength, antibacterial, flame-retardant bio-adhesive.

Full Bio‐Based Soy Protein Isolate Film Enhanced by Chicken Feather Keratin

“…In Figure 2, the absorbance peaks located at 1625, 1528, and 1240 cm −1 correspond to amide I (CO stretching vibration), amide II (NH bending), and amide III (CN and NH stretching). [ 25 ] Amide I, the strongest absorption band in protein, is useful for the analysis of the protein secondary structure and the peak at 1625 cm −1 indicates β‐sheet structure. [ 26,27 ] Compared with the spectra of chicken feather, the peak of FK shift from 1625 to 1633 cm −1 , indicated decreased amounts of ordered β‐sheets.…”

“…The broad peak (3600–3100 cm −1 ) observed at ≈3283 cm −1 was contributed to the OH and NH (free and bounded). The signals observed at 1635, 1528, and 1240 cm −1 correspond to amide I (CO stretching vibration), amide II (NH bending), and amide III (CN and NH stretching), [ 25 ] respectively. In the Raman spectra of proteins and peptides, the stretching vibration bands of disulfide bonds appeared in the range of 500–550 cm −1 .…”

Fire-resistant cellulose boards from waste newspaper, boric acid salts, and protein binders

“…The highly porous structure is a direct consequence of the low-pressure forming process employed. The good adherence of the components, re ected by the formation of a layer of protein binder on the surface of the bers and the presence of borax and boric acid microcrystals adhered to this layer, can be explained based on the ndings of Gu et al (2020) about the crosslinking of the soy protein in the presence of borate. Similar behavior in terms of the formation of a protein layer on the surface of the bers has also been reported for other systems such as soy protein/ ax bers (El Hajj et al, 2012) and pea protein/ ax bers (Lazko et al, 2013).…”

“…Among these alternative raw materials, cellulose-rich materials, such as recycled bers and agricultural waste, in combination with natural-based binders have received particular attention as construction materials due to their eco-friendly nature and favorable thermal and acoustic properties. The major drawback of these materials for construction applications is their low re resistance, which can be improved by the use of additives such as boric acid and borax (Aksogan et al 2018;Buratti et al 2016;Gu et al 2020;Lopez Hurtado et al 2016;Nagieb et al 2011, Ricciardi et al 2014Yeon et al 2014). Although boric acid and borax are classi ed by the European Chemicals Agency (ECHA) as repro-toxic (Category 1B with the hazard statement of H360FD) in the Classi cation, Labelling and Packaging (CLP) Regulation, this same agency allows its use in building and construction work (ECHA) and there are companies which supply borates for urbanization applications (p.ex., U.S. Borax -Rio Tinto).…”

“…Table 1 shows some relevant studies related to the production of boards from alternative raw materials and naturalbased binders and includes their re-resistance information. Besides, Gu et al (2020) have shown that soy protein can crosslink in the presence of borate, leading to good adhesive properties. (Khosravi et al 2010) The boards described in Table 1 have been produced through three manufacturing methods: hot-press molding (Mahmood et al 2016;Khosravi et al 2010), bond molding (Cai et al 2016;Lazko et al 2013;Palumbo et al 2015) and blending microwave radiation (El Hajj et al 2012).…”