Lignosulfonate and glycidyl ether modified urea formaldehyde wood adhesives for interior particleboard production

Abstract

Purpose The purpose of this study is the development of sustainable and low-formaldehyde emission wood adhesive formulations. Design/methodology/approach Three-step urea formaldehyde (UF) resin has been in situ modified with calcium lignosulfonate (LS) and/or 1,4 butanediol diglycidyl ether (GE). The structural, chemical, thermal and morphological characterizations were carried out on resin samples. These resins have been applied for particleboard pressing, and UF, UF-LS and UF-GE were evaluated as P2 classes according to EN 312. Findings The results show that the improved LS- or diglycidyl ether-modified UF wood adhesives were successful in their adhesive capacity, and the formaldehyde content of the final product was obtained as low as 8 mg/100 g. This paper highlights that the presented adhesive formulations could be a potential eco-friendly and cost-effective alternative to formaldehyde-based wood adhesives for interior particleboard production. Research limitations/implications Combination of LS and GE resulted in weaker mechanical properties and fulfilled P1 class particleboards due to temperature and duration conditions. Therefore, in situ usage of LS or GE in UF resins is highly recommended for particleboard pressing. Formaldehyde content of particleboards was determined with the perforator method according to EN 12460-5 and all of the particleboards exhibited E1 class. LS was more efficient in decreasing formaldehyde content than GE. Practical implications This study provides the application of particleboards with low formaldehyde emission. Social implications The developed LS- and diglycidyl ether-modified UF resins made it possible to obtain boards with significantly low formaldehyde content compared with commercial resins. Originality/value The developed formaldehyde-based resin formulation made it possible to produce laboratory-scale board prototypes using LS or GE without sacrificing of press factors and panel quality.