The role of lignin in enhancing adhesion performance and reducing formaldehyde emissions of phenol-resorcinol-formaldehyde resin adhesives.

Phenol-resorcinol-formaldehyde (PRF) resins are widely used as adhesives in laminated wood products due to their excellent strength and durability. However, when cured under cold-press conditions, PRF resins encounter several challenges, including the presence of unreacted free phenol in the resin solution, which remains unreacted with formaldehyde at ambient temperature. Excessive free phenol not only reduces the resin's reactivity but also poses environmental and health risks.

Exploring nanolignin as a sustainable biomacromolecule in polymer composites: Synthesis, characterization, and applications: A review.

Nanolignin is a biomacromolecule nanomaterial obtained from lignin, a natural plant polymer. It has attracted considerable attention as a potential nanofiller for polymer composites owing to its remarkable properties, such as biodegradability, antioxidant activity, and high specific surface area. However, the development of biological macromolecule nano lignin-based polymer composites faces several challenges, mainly due to the complex structure and poor chemical compatibility of lignin with most polymers.

Crosslinking reactions of a model aminated lignin compound as a platform for building thermosetting polymers for lignin-based bio adhesives.

As millions of tons of kraft lignin are being wasted, a potential application is to use its crosslinking reactions to build thermosetting bio adhesives. However, the crosslinking reactions between lignin molecules are not fully understood. The present study aims to elucidate the crosslinking reactions of the model lignin compound guaiacylglycerol-β-guaiacyl ether (GGE) via one-step hydroxymethylation/ amination with formaldehyde and diethylenetriamine (DETAM), or one-step glyoxylation/ amination with glyoxal and DETAM via liquid NMR techniques such as H NMR, C NMR, 2D H-C, and H-N HSQC NMR.

Eco-Friendly and High-Performance Bio-Polyurethane Adhesives from Vegetable Oils: A Review.

Current petrochemical-based adhesives adversely affect the environment through substantial volatile organic compound (VOC) emissions during production, contributing to air pollution and climate change. In contrast, vegetable oils extracted from bio-resources provide a compelling alternative owing to their renewability, abundance, and compatibility with adhesive formulation chemistry. This review aimed to critically examine and synthesize the existing scholarly literature on environmentally friendly, sustainable, and high-performance polyurethane adhesives (PUAs) developed from vegetable oils.

Chemical and Thermal Characteristics of Ion-Exchanged Lignosulfonate.

Lignosulfonate features sulfonate groups, which makes it soluble in water and hence, suitable for a wide range of applications. However, its characterization is challenging because of its limited solubility in organic solvents. Thus, this study investigated the chemical and thermal characteristics of ion-exchanged sodium lignosulfonate (Na-LS) and compared it with those of industrial kraft lignin derived from softwood and hardwood.

A comprehensive review of the synthesis strategies, properties, and applications of transparent wood as a renewable and sustainable resource.

The uncertainties of the environment and the emission levels of nonrenewable resources have compelled humanity to develop sustainable energy savers and sustainable materials. One of the most abundant and versatile bio-based structural materials is wood. Wood has several promising advantages, including high toughness, low thermal conductivity, low density, high Young's modulus, biodegradability, and non-toxicity.

The role of acetone-fractionated Kraft lignin molecular structure on surface adhesion to formaldehyde-based resins.

One of the key strategies for valorizing kraft lignin (KL) into value-added products such as bio-based adhesives is to perform solvent fractionation of KL to produce lignin with improved homogeneity. Understanding the structure and properties of fractionated KL will aid in the selection of the best samples for certain applications. In this study, acetone-fractionated KL from softwood and hardwood was characterized to understand its chemical structure, elemental composition, molecular weight, and thermal properties.