Improving Properties of Starch-Based Adhesives with Carboxylic Acids and Enzymatically Polymerized Lignosulfonates

Abstract

A novel strategy for improving wet resistance and bonding properties of starch-based adhesives using enzymatically polymerized lignosulfonates and carboxylic acids as additives was developed. Therefore, lignosulfonates were polymerized by laccase to a molecular weight of 750 kDa. Incorporation of low concentrations (up to 1% of the starch weight) of 1,2,3,4-butanetetracarboxylic acid (BTCA) led to further improvement on the properties of the adhesives, while addition of greater amounts of BTCA led to a decrease in the properties measured due to large viscosity increases. Great improvements in wet-resistance from 22 to 60 min and bonding times (from 30 to 20 s) were observed for an adhesive containing 8% enzymatically polymerized lignin and 1% BTCA. On the other hand, the addition of citric acid (CA) deteriorated the properties of the adhesives, especially when lignosulfonate was present. In conclusion, this study shows that the addition of the appropriate amount of enzymatically polymerized lignosulfonates together with carboxylic acids (namely BTCA) to starch-based adhesives is a robust strategy for improving their wet resistance and bonding times.

Production of Chemically Modified Bio-Based Wood Adhesive from Camote and Cassava Peels

“…Food security will also be a concern once the starch-based adhesive is fully adopted. Exploring starch-based adhesives has become a recent research interest, such as the studies on biobased adhesives formulated from tannic acid, chitosan, and shellac [ 27 ], research on starch-based adhesives for wood panels [ 28 ], improvement of starch-based adhesives with carboxylic acids and enzymatically polymerized lignosulfonates [ 29 ], and evaluation of the properties of starch-based adhesives [ 30 ], to name a few. Many studies have been conducted on the potential of starch as a bioadhesive, but the potential consequences of utilizing starch-based adhesives were poorly given attention.…”

Properties of Bark Particleboard Bonded with Demethylated Lignin Adhesives Derived from <i>Leucaena leucocephala</i> Bark

“…These adhesives exhibit good compatibility with other bio-based materials, enhancing the sustainability of composite materials [43]. They also contribute to the enhancement of mechanical properties in composites, such as strength and stiffness [44]. Demethylated lignin adhesives offer versatility in formulation, allowing for adjustments to meet specific application requirements.…”

A Novel Bio-Adhesive Based on Chitosan-Polydopamine-Xanthan Gum for Glass, Cardboard and Textile Commodities

“…They are described as natural mediators for surface adhesion in nature, often in conjunction with other compounds [7]. Recently, an adhesive based on starch and lignosulphonate crosslinked with laccase, has been proposed for the bonding of paper [8,9]. A new adhesive formed by epoxidized kraft lignin in the form of lignin nanoparticles and biocolloids has produced a strong adhesive for wood comparable to commercially available ones [10].…”