A nontoxic glue for plywood—from glucose, citric acid

The materials for building home furniture,cor and floors come in large sheets. Particleboard, fiberboard, and plywood are usually made with glues and resins that contain formaldehyde, a probable carcinogen. Researchers have combined sugar and an orange juice ingredient into a wood glue that is water resistant.

To make plywood, manufacturers glue together thin layers of wood and then cure the material under pressure and heat, creating large, flexible panels. One of the most common glues is urea-formaldehyde, which is inexpensive and bonds to wood very well. Health and environmental concerns have been raised by the emissions from plywood with this type of resin. Studies have shown that wood glue can be made from solutions of sugar and acid. The zinc chloride catalyst is needed to decrease the energy consumption for the plywood curing. Hong Lei and his colleagues wanted to see if pure glucose and citric acid could produce a strong glue.

The sticky liquid that they applied to the poplar veneer was created by heated solutions of glucose and citric acid. They pressed the three veneered sheets into a single sheet for six minutes. The team cut the sheets into smaller pieces for strength tests and found that the plywood samples broke along the wood fibers and not at the glue seams. The standard requirement for plywood in China is satisfied by these results. When the plywood samples were soaked in hot or boiling water, only the ones made with citric acid toglucose ratios above 0.6 had adhesive strengths that satisfied the standard requirement. The wood-binding strength and water-resistance were increased by the increase in ester links between citric acid and wood. The wood products industry holds promise for the use of icti acid -glucose glues.

More information: Fully biobased adhesive from glucose and citric acid for plywood with high performance, ACS Applied Materials & Interfaces (2022). DOI: 10.1021/acsami.2c02859 Journal information: ACS Applied Materials and Interfaces Citation: A nontoxic glue for plywood—from glucose, citric acid (2022, May 11) retrieved 11 May 2022 from https://phys.org/news/2022-05-nontoxic-plywoodfrom-glucose-citric-acid.html This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only.