Study of improvement of bonding properties of Larch glued laminated timber

Purpose - The purpose of this paper is to improve the adhesion of Larch wood, by conducting a study of hydrogen peroxide treatment on Larch wood surfaces. Design/methodology/approach - Effect of surface treatment of Larch by H2O2 on the adhesion of Larch wood, as indicated by compression shear strength, was examined in this paper. Surface properties of Larch wood, such as contact angle were evaluated. Shear strength tests for measuring adhesion of Larch blocks were conducted. Fourier transform infrared (FTIR) analysis was employed to examine the chemical functionality of the untreated and treated Larch surface. Findings - It is found that hydrogen peroxide treatment improved the adhesion of Larch glued laminated timber. The dry compression shear strength of Larch glued laminated timber treated with H2O2 solution is increased by 19.7 per cent compared with the untreated Larch glued laminated timber. FTIR results showed that the intensity of absorption band at 1,730 cm(-1) for H2O2 solution-treated Larch increased as compared with the untreated Larch wood. The results of contact angle showed that wettability of Larch treated with H2O2 solution increased markedly compared with the untreated Larch. Research limitations/implications - The improvement of adhesion as a result of hydrogen peroxide treatment mainly applies to radial Larch surface. Practical implications - This study provided a simple and practical solution to improving the adhesion of Larch laminated timber glued with water-based Polymer Isocyanate (WPI) adhesive. Such a hydrogen peroxide surface treatment may be applied to other types of wood. Originality/value - This method of improving the adhesion of Larch glued laminated timber can be used for other Larch products glued with WPI.