Relevance between Cassava Starch Liquefied by Phenol and Modification of Phenol-Formaldehyde Resin Wood Adhesive

Abstract

A novel type of phenol-formaldehyde (PF) resin was prepared by utilizing the liquefaction products liquefied by phenol under acidic conditions and then reacted with formaldehyde under alkaline conditions. The relationship between the liquefaction behavior of cassava starch and the properties of modified PF resin wood adhesive was studied. The effects of the liquid–solid ratio of phenol to cassava starch, sulfuric acid usage, and liquefaction time on the liquefaction residue rate and relative crystallinity of cassava starch were determined. The results showed that the bonding strength of modified PF resin decreased gradually with the decrease of the liquid–solid ratio. It was a great surprise that bonding strength still met the requirement of the national standard of 0.7 MPa when the liquid–solid ratio was 1.0. The detailed contents were analyzed through FT-IR, SEM, and XRD. In terms of the utilization of bio-materials for liquefaction to synthesize wood adhesive, cassava starch may be superior to the others.

Recent progress of biomass in conventional wood adhesives: a review

“…121,122 However, the production cost of phenol has become increasingly expensive as its price rises with the increasing depletion of fossil fuels. 123 Starch is an abundant source with excellent properties such as being renewable, biodegradable and inexpensive, and is widely utilized in numerous industries such as the food, pharmaceutical, textile and chemical industries. 124–126 In the wood adhesive sector, starch has long been used for the preparation of starch-based adhesives.…”

“…129 Therefore, combining starch with PF resins to develop new wood adhesives is a promising direction. Liu et al 123 successfully synthesized new PF resins from cassava starch by initially subjecting phenol to liquefaction under acidic conditions, followed by a reaction with formaldehyde under alkaline conditions. By incorporating liquefaction products of cassava starch, the CPF resin exhibited adhesive strength nearly equivalent to that of PF resin, while displaying reduced formaldehyde emission levels under identical reaction conditions.…”

Evaluation of the use of vineyard pruning biomass (bobal variety) in constructive bioproducts

“…Following these concerns, several studies have been carried out in manufacturing particleboards with natural resins and adhesives, such as proteins, lignins, tannins, glutens, starches, citric acid, etc. (El-Wakil et al 2007;Ciannamea et al 2010;Lei et al 2010;Moubarik et al 2010;Wang et al 2011;Ferrández-García et al 2012;Ferrández-García et al 2019;Liu et al 2022).…”