This research focused on physical and mechanical properties of biocomposite made from bamboo and citric acid as natural binder. Bamboo particles was mixed with citric acid at 0 – 40 wt% resin content based on air-dried particles and each mixture was hot pressed at 180 °C for 10 min. The result showed that addition of citric acid could improve significantly the physical and mechanical properties of particleboard. The thickness swelling was 50 % for bamboo binderless particleboard (0 wt%), whereas it decreased to 7 % under a resin content of 10 wt%. The optimum resin content in this study was 30 wt%, while the modulus of rupture dan the modulus of elasticity were 14 MPa and 4.5 GPa, respectively. The ester linkages were detected by Fourier transform infrared spectroscopy, indicating that carboxyl groups from citric acid reacted with hydroxyl groups from bamboo to produce better properties of particleboard, especially its dimensional stability. Based on these results, it was concluded that citric acid could be as a potential natural binder for bamboo particleboard.

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The people of Gunungkidul have long experience in rehabilitation program. They manage marginal land be productive community forest. While, the quality of timber from community forest is lower than produced by Perhutani. It is caused the community forest has not been applied intensive silviculture technique. This community engagement program aims to: (1) up grade the farmer knowledge about intensive silviculture technique; (2) rise the farmer awareness for importance of applying intensive silviculture technique; (3) build up the farmer skill to apply intensive silviculture technique; (4) motivate the farmer to produce superior teak seedling and organic fertilizer independently. The target group of this program is the farmer group of Ngudi Makmur at Watusigar Village, Ngawen District, Gunungkidul Regency. This program was held on 2015 to 2016. The methods applied in this program are socialization, field study, training, practice, and technical assistance. The results of this program are demonstration plot of superior teak stand, hedge orchard and nursery of superior teak, and organic fertilizer using Trichoderma sp. This program also succesfull for increase of knowledge, awareness, skills and independence of farmer in applying of intensive silviculture technique.