Assessment of Sustainability of Bio Treated Lignocellulose-Based Oleogels

Abstract

The development of biological strategies to obtain new high-added value biopolymers from lignocellulosic biomass is a current challenge for scientific community. This study evaluates the biodegradability and ecotoxicity of new formulated oleogels obtained from fermented agricultural residues with Streptomyces, previously reported to show improved rheological and tribological characteristics compared to commercial mineral lubricants. Both new oleogels exhibited higher biodegradation rates than the commercial grease. Classical ecotoxicological bioassays using eukaryotic organisms (Lactuca sativa, Caenorhabditis elegans) showed that the toxic impact of the produced bio-lubricants was almost negligible and comparable to the commercial grease for the target organisms. In addition, high throughput molecular techniques using emerging next-generation DNA-sequencing technologies (NGS) were applied to study the structural changes of lubricant-exposed microbial populations of a standard soil. Results obtained showed that disposal of biomass-based lubricants in the soil environment did not substantially modify the structure and phylogenetic composition of the microbiome. These findings point out the feasibility and sustainability, in terms of biodegradability and eco-safety, of the new bio-lubricants in comparison with commercial mineral greases. This technology entails a promising biological strategy to replace fossil and non-renewable raw materials as well as to obtain useful biopolymers from agricultural residues with potential for large-scale applications.

Lignocellulosic Materials for the Production of Biofuels, Biochemicals and Biomaterials and Applications of Lignocellulose-Based Polyurethanes: A Review

“…Furthermore, several residual lignin fractions from bioethanol or Kraft pulping processes of different species were valorised, exhibiting good properties as lubricant thickeners but dependent on the lignin origin, composition and extraction method [ 291 , 292 , 293 ]. Some of these formulations were tested for biodegradability and ecotoxicity, showing generally that there is no harm or danger to their disposal [ 294 ]. On the other hand, lignin-based lubricating greases formed with a polyurea-polyurethane thickener have also been patented lately [ 295 ].…”

A Review of Rigid Polymeric Cellular Foams and Their Greener Tannin-Based Alternatives

“…Microorganisms, bacteria, and enzymes break down polymer chains into smaller molecules that can leach into the soil and water. Most studies on foam degradation have focused on PUR foams [ 190 ]. The decomposition of PUR has been studied in order to track the stages of polymer degradation [ 191 ].…”

“…Tannin foams have very good fire resistance properties, even without the addition of flame retardants [ 260 , 261 ], as the energy input required to start combustion corresponds to severe conditions [ 220 , 253 , 260 , 261 ]. For instance, when comparing PF foams and TFFs by applying an incident heat flux of 50 kW·m −2 , an ignition time of 6s was observed for the former [ 108 ], while no ignition was observed for the latter [ 190 ]. This unique behavior conferred by tannin allows the derived foams to stand out from other insulation materials, a property that is often a critical point, and is a major vulnerability of PUR foams, in particular.…”

Toward UV-Triggered Curing of Solvent-Free Polyurethane Adhesives Based on Castor Oil

“…Noteworthy in this context is that vegetable oils not only provide an integrative reactive component of bioadhesive formulations but also constitute the fluid medium for the polymerization processes that lead to the adhesive polymer network. Among the adhesives prepared from such natural resources, polyurethanes are among the most widely studied ones. ,− Besides, polyurethanes, based on vegetable oils, have been demonstrated to exhibit low ecotoxicity and high biodegradability …”

“…1,8−13 Besides, polyurethanes, based on vegetable oils, have been demonstrated to exhibit low ecotoxicity and high biodegradability. 14 Polyurethanes that are derived from renewable resources exhibit suitable properties for using them as adhesives and coatings for wood and chipboard, plastic, or metal surfaces. 5−9 However, their functional performance has still ample room for improvement to turn them into serious alternatives to their purely synthetic counterparts.…”