Anatomical, chemical, physical and mechanical properties of rubber wood in the Philippines

The physical properties (relative density, moisture content (MC) and shrinkage), and mechanical properties (static bending, compression parallel and perpendicular-to-grain, shear, hardness and toughness), anatomical (fiber length and diameter, lumen diameter and cell wall thickness, vessel length and width), and chemical properties (ash content, hot water extractives, sodium hydroxide, and starch content of two (2) rubberwood varieties (P260 and P600) are presented. The relative density mean value of rubberwood P 260 (0.48) was lower than P600 (0.53). As per relative density classification, rubberwood P260 mean values fell under Group IV (moderately low), while P600 under Group Ill (medium) For the MC, P260 (125.94%) was higher than P600 (102.89%). Inverse relationship between relative density and MC as also reported in literature was observed. On the other hand, the volumetric shrinkage (ShVol) of P260 (7.21%) was lower than P600 (7.58%) although both fell under low ShVol (Group V). The mechanical properties of rubberwood P600 fall under moderately low (C4) while P260 under low (C5). The ash content of P600 (0.20%) was lower than P260 (0.28%) while the hot water solubility, sodium hydroxide soluble and starch content of rubberwood P600 (4.47%), (21.57%) and (2.00%) were higher than P260 (2.85%), (20.37%) and (0.96%). Fiber length (1.2793 mm) and diameter (0.0297 mm), lumen diameter (0.0218 mm), vessel length (0.7529 mm) and diameter (0.2591 mm) of rubberwood P260 were higher than those of rubberwood P600 (1.2021 mm), (0.0270 mm), (0.0179 mm), (0.6601) and (0.2316). Based on the anatomical, chemical, physical and mechanical properties, rubberwood is recommended for end-uses such as furniture, wood carvings, pallets and other light to moderately light construction purposes particularly those requiring dimensional stability. Likewise, the wood showed potential for pulp and paper making as indicated by low ash content and anatomical properties confirmation.