ABSTRACT

The citric acid (CA)-based adhesive, as a new environment-friendly adhesive, has been developed and used for the manufacturing of plywood to resolve the problem of formaldehyde-based adhesive for human health. The effects of pressing time and temperature on physical and mechanical properties of plywood were examined. Three-layer plywood panels were bonded using CA adhesive with a 134 g/m² of single glue spread on White jabon wood veneer. The plywood panels were hot-pressed at 5 MPa with three different pressing temperatures, 180°C, 190°C, 200°C, for 10 min, and also different pressing times, 4, 7, 10 min at 190°C. The physical and mechanical properties, such as moisture content, delamination, and shear strength, were evaluated according to JAS 233:2003. The results show that the plywood with pressing temperature of 190°C for 10 min had lower delamination and greater tensile shear strength than those of other plywood panels. Moreover, some properties of the plywood fulfilled the requirement of JAS 233:2003. Based on the FTIR analysis, citric acid plays an important role in the formation of ester linkages (R-COO-R) via esterification between carboxyl groups of citric acid and hydroxyl groups of White jabon wood veneer, resulting excellent properties of plywood.

摘要

柠檬酸（CA）基胶粘剂作为一种新型环保胶粘剂，已被开发用于胶合板的制造，以解决甲醛基胶粘剂对人体健康的影响。考察了压制时间和温度对胶合板物理机械性能的影响。^{使用 134 g/m 2}的 CA 粘合剂粘合三层胶合板面板单胶涂在白色 jabon 木单板上。胶合板在 5 MPa 下进行热压，三种不同的压制温度，180°C、190°C、200°C，持续 10 分钟，以及不同的压制时间，在 190°C 下分别为 4、7、10 分钟。根据 JAS 233:2003 评估物理和机械性能，例如水分含量、分层和剪切强度。结果表明，与其他胶合板相比，压制温度为 190°C 10 分钟的胶合板具有更低的分层和更高的拉伸剪切强度。此外，胶合板的某些性能满足 JAS 233:2003 的要求。基于 FTIR 分析，柠檬酸通过柠檬酸的羧基与白檀木单板的羟基之间的酯化作用在酯键 (R-COO-R) 的形成中起着重要作用，