An Eco-Effective Soybean Meal-Based Adhesive Enhanced with Diglycidyl Resorcinol Ether

A biomimetic adhesive with high adhesion strength and toughness comprising soybean meal, chitosan, and condensed tannin-functionalized boron nitride nanosheets

Soybean meal (SM)-based adhesive can solve the issues of formaldehyde emission and over-reliance of aldehyde-based resins but suffers from poor water resistance, weak adhesion strength, and high brittleness. Herein, a high-performance adhesive inspired by lobster cuticular sclerotization was developed using catechol-rich condensed tannin-functionalized boron nitride nanosheets (CT@BNNSs), amino-containing chitosan (CS), and SM (CT@BNNSs/CS/SM). The oxidative crosslinking between the catechol and amino, initiated by oxygen at high temperatures, formed a strengthened and water-resistant interior network. These strong intermolecular interactions induced by phenol-amine synergy accompanied by the reinforcement of uniformly dispersed BNNSs improved the load transfer and energy dissipation capacity, endowing the adhesive with great cohesion strength. Given these synergistic effects, the biomimetic CT@BNNSs/CS/SM adhesive caused noticeable improvements in water tolerance, mechanical strength, and toughness over the neat SM adhesive, e.g., enhanced wet shear strength (1.46 vs. 0.66 MPa, respectively), boiling water shear strength (0.92 vs. 0.43 MPa, respectively), and debonding work (0.368 vs. 0.113 J, respectively). Thus, this study provided a green and low-cost bionic strategy for the preparation of high-performance biomass adhesives.

Effects of Different Denaturants on the Properties of a Hot-Pressed Peanut Meal-Based Adhesive

Plant protein-based adhesives could fundamentally solve the problem of formaldehyde-based adhesive releasing formaldehyde, but enhancing bonding strength and water resistance is a necessary measure to realize practical applications. In this study, the effects of different denaturants on the properties of a hot-pressed peanut meal (HPM)-based adhesive before and after crosslinking were studied. Papain, sodium dodecyl sulfate (SDS), urea and crosslinker-polyamide epichlorohydrin (PAE) were used to prepare HPM-based adhesives. The functional groups, bonding strength, thermal behaviors, mass loss, moisture uptake value, viscosity and fracture surface of adhesive samples were analyzed. As a result, (1) papain was used to break HPM protein (HPMP) into polypeptide chains and to reduce the water resistance. (2) SDS and urea unfold the HPMP molecule and expose internal hydrophobic groups to improve the water resistance of the adhesive. (3) A denser network structure was formed by PAE and HPMP molecules, which significantly improved the bonding strength and water resistance of adhesives. In particular, after SDS denaturation and PAE crosslinking, compared with pure HPM adhesive, the wet shear strength increased by 96.4%, the mass loss and moisture uptake value reduced by 41.4% and 69.4%, and viscosity increased by 30.4%. This work provided an essential guide to design and prepare HPM-based adhesives.

Oilseed Cakes in the Food Industry; A Review on Applications, Challenges, and Future Perspectives

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By-products from the food sector now have a wide range of applications. Low-cost raw materials, followed by low-cost goods, are regarded as one of the sectors’ top goals. Because of its economic relevance, reduced price, and nutrients such as protein, fiber, carbs, and antioxidants, oilseed cakes (OCs) have found a desirable place in livestock and poultry feed. Furthermore, because the cake has the same desirable nutrients, its usage in the food business is unavoidable. However, its use in this sector is not simply for nutritious purposes and has it has different impacts on flavor, texture, color, and antioxidant qualities. Therefore, as a result of its desirable qualities, the cake can be more useful in extensive applications in the food business, as well as in the manufacture of supplements and novel foods. The current review looks at the reapplications of byproducts obtained from oilseeds (soybean, sunflower, sesame, canola, palm kernel, peanut, mustard, and almond) in the food sector in the future. Furthermore, allergenicity, toxicity, antinutritional compounds, and techniques of extracting cakes from oilseeds have been discussed.

Conversion and transformation of N species during pyrolysis of wood-based panels: A review

Understanding the migration and conversion of nitrogen in wood-based panels (WBPs) during pyrolysis is fundamentally important for potentially transforming the N-containing species into valuable material-based products. This review firstly summarizes the commonly used methods for examining N evolution during the WBPs pyrolysis before probing into the association between the wood and adhesives.The potential effects of wood-adhesive interaction on the pyrolysis process are subsequently analyzed. Furthermore, the controversial statements from literature on the influence of adhesives on wood pyrolysis behavior are discussed, which is followed by the detailed investigation into the distribution and evolution of N-containing species in gas, liquid and char, respectively, during WBPs pyrolysis in recent studies. The differences in N species due to the heating sources (i.e. electrical heating vs microwave heating) are particularly compared. Finally, based on the characteristics of staged pyrolysis, co-pyrolysis and catalytic pyrolysis, the converting pathways for WBPs are proposed with an emphasis on the production of value-added chemicals and carbon materials, simultaneously mitigating NO_x emission.