Gum Arabic (GA) was used as a binder for the fabrication of Rhizophora spp. particleboards. The physical and mechanical properties of the bioadhesive bonded particleboards, including moisture content, inter- nal bond (IB) strength, thickness swelling (TS), water absorption (WA) and field-emission scanning elec- tron microscopy (FESEM) were used to characterize the manufactured particleboards. Three different particle sizes of the Rhizophora spp. with four adhesive levels were utilized. Results revealed that the addition of GA into the particleboards noticeably improved panel overall properties. The GA bonded par- ticleboards resulted in smoother surfaces, more rigid texture and better internal bonding strength com- pared to binderless particleboards made without using any adhesive. All specimens had internal bond strength of more than the minimum requirement of the Japanese Industrial Standard JIS A-5908 Type-
8 of 0.15 N/mm2 and were noticed to increase by increasing the adhesive level. However the GA bonded
particleboards had higher percentage of WA and the TS compared with the binderless boards. Micro- scopic study also revealed that particleboards bonded with the gum had better contact compared to the binderless boards. Based on these results, it could be concluded that gum Arabic is an effective natural substance that could be added to manufacture particleboards to improve some of panels’ physical and
mechanical properties.