Short notes: A Chemotaxonomic Study of the Resins from Three Dipterocarp Species (Shorea macrophylla, Shorea pinanga, and Shorea hopeifolia)

A chemotaxonomic study on the resins of Shorea macrophylla, Shorea pinanga, and Shorea hopeifolia was conducted. The dichloromethane extracts were separated into neutral and acidic fractions and then analyzed using GC-MS. The neutral fraction analysis revealed that spathulenol, caryophyllene oxide, aromadendrene oxide, and isoaromadendrene epoxide were the major constituents in all three species. Furthermore, the main compound in the neutral fraction of Shorea hopeifolia was isocaryophyllene which was undetected in the other two species. The major constituent of the acidic fraction of the three species was hexadecanoic acid, while pentadecanoic acid was the major constituent in the acidic fraction of Shorea pinanga and Shorea hopeifolia. Therefore, the presence of sesquiterpenes as well as fatty acids in S. macrophylla, S. pinanga, and S. hopeifolia was discovered to be a marker for identifying the genus Shorea.

Bond performance of formaldehyde-based resins synthesized with condensate generated during kiln-drying step of wood

This research investigated the potential use of condensate generated during vacuum drying with high frequency of wood in the synthesis of urea-formaldehde (UF) and melamineformaldehyde (MUF) resins. The liquid condensate (5 wt%) of total resin composition) of walnut, beech or oak was replaced with deionized water used in the synthesis of UF and MUF resins. The condensate did not affect the properties of the UF and MUF resins in terms of density, solid content, viscosity, pH, and gel time as compared with the control resins. The control UF and MUF resins did not show a significant difference with the bond strength of UF and MUF resins at dry and wet conditions, except for the oak-UF resin. As for the dry condition, the control resin had the highest bond strength with a value of 12.9 N. mm-2, followed by beech-UF resin (12.6 N. mm-2), walnut-UF resin (12.1 N. mm-2), and oak-UF resin (11.8 N. mm-2), respectively. A similar trend was observed for the wet condition. All the modified UF and MUF resins complied with the minimum requirements of EN 12765 standard at dry and wet conditions. The results of this research can be useful for environmentally friend solution of the waste condensate discarded to the ground water.