Residual Brewer’s Yeast Biomass and Bacterial Cellulose as an Alternative to Toxic Phenol-Formaldehyde Binders in Production of Pressed Materials from Waste Wood

Abstract

Pressed composites can be produced from wood sawdust waste using modified yeast biomass, waste as a bio-adhesive, ultra-dispersed bacterial cellulose (UBC) as a binder, and preliminary chemical crosslinking. The materials obtained were not inferior to traditional materials based on the required levels of toxic phenol-formaldehyde resin and physical and mechanical parameters. Physical and mechanical properties of the materials depended on the amount and viscosity of the binder, as well as on the chemical structure and conditions of chemical cross-linking and modified UBC application. The strengths of the best examples of the materials obtained were approximately 17 to 20 MPa, the densities were in the range of 1207 to 1255 kg/m 3 , and the water absorption was less than 20%. During hot pressing, notable changes were observed in the wood particles at FTIR-ATR spectra frequencies of 3620 cm -1 , 3600 to 3000 cm -1 , 2920 cm -1 , 2850 cm -1 , 1770 cm -1 , 1650 cm -1 , 1560 cm -1 , and 1089 cm -1 . This is mainly due to the chemical and structural changes in lignin, hemicellulose, and binder.

Preparation of Biocomposites using Sawdust and Lignosulfonate with a Culturе Liquid of Levan Producer Azotobacter vinelandii as a Bonding Agent

“…Taking into account earlier studies and scientific data (Semochkin and Pashkov 2002;Kadimaliev et al 2012;Privas and Navard 2013;Yuan et al 2014;Kadimaliev et al 2015), the following ratios of LGS to sawdust were chosen: 30:70; 50:50; 60:40; and 70:30 g/g. For monitoring, we used biocomposites derived without the addition of LGS as a control sample.…”

“…1b) derived from pressing sawdust without LGS, the following absorption bands were observed: 3600 to 3000 cm -1 , caused by valence vibrations of OH-groups involved in hydrogen bonding in cellulose, lignin, and hemicellulose (Bazarnova et al 2002;Fengel and Wegener 2003;Kadimaliev et al 2015); 2920 and 2850 cm -1 of CH valence vibrations of methyl and methylene groups in lignin (Bazarnova et al 2002;Fengel and Wegener 2003); 1734 cm -1 of C=O vibration in the ester group of hemicelluloses (uronic acids) (Bazarnova et al 2002;Muller et al 2009); 1635 cm -1 adsorption of O-H groups and conjugated C-O bonds or carbonyl and carboxyl groups in lignin (Pandey and Pitman 2003); 1400 cm -1 vibrations of CH3 groups of lignin; 1247 cm -1 skeletal vibrations of a syringal and guaiacyl core in lignin and of C-H groups of hemicelluloses; and 1043 cm -1 that of aromatic C-H bonds (Bazarnova et al 2002;Pandey and Pitman 2003).…”

“…Meanwhile, there are data in the literature indicating that it is possible to use composites derived from modified bio-organic waste and microbial polysaccharides as substitutes for glues of a natural origin. For example, it has been shown that modifying barmy waste creates adhesive properties and enables the material to be used as a bioglue for paper, fabric, and wood Kadimaliev et al 2012Kadimaliev et al , 2015. Microbial polysaccharides such as levan and dextran also possess adhesive properties.…”

Optimization of Cultivation Conditions for Azotobacter vinelandii D-08, Producer of the Polysaccharide Levan, for Obtaining Biocomposite Materials

“…Fourier IR spectroscopy was used to evaluate the chemical and structural changes that occurred during hot pressing (Fengel and Wegener 2003;Fabo 2004;Müller et al 2009;Kadimaliev et al 2015). This method also allowed for an analysis of the formation of bonds between wood particles and levan or other components in the binder.…”

Biobased Materials from Microbial Biomass and Its Derivatives

“…Some of these biopolymers could be more expensive than the plant-based polymers; however, research on new methods and the use of low-cost culture media, such as alternative carbon and nitrogen sources, may reduce the production of more expensive EPS [7]. Yeast and fungal biomass are low-cost and abundant sources of biopolymers, since they could be a residue from some industrial processes such as the brewing industry [31,37] or other biotechnological processes [38] where the biomass (cells or mycelia) is discarded after obtaining the final product.…”