Ganis Lukmandaru
Bagian Teknologi Hasil Hutan, Fakultas Kehutanan, Universitas Gadjah Mada

Published : 49 Documents
Articles

Komponen Kimia Kayu Jati dengan Pertumbuhan Eksentris Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 5, No 1 (2011)
Publisher : Jurnal Ilmu Kehutanan

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The objective of this study is to learn the quality of abnormal woods. The specimens were 10 leaning trees obtained from thinned teak (Tectona grandis L.f.) stand in Randublatung, Central Java. In each tree, the eccentric growth parts were isolated, then wood meal sample was drilled at the outer heartwood part of both maximum annual-ring width (upper part of leaning stem) and in its opposite side, which had minimum annual-ring width (lower part of leaning stem). The wood meals were ground to size of 40-60 mesh for chemical analysis. Data analysis by paired t-test showed that no significant difference was found between the upper and lower parts in ethanol-benzene extractive content (4-12%), hot-water soluble content (1-3%), ash content (0.73%) and acid soluble lignin content (0.7-1.4 %) . By means of Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS), no striking difference was also observed in the levels of major components of ethanol-benzene extracts. On the other hand, in Klason lignin content, the wood with widest ring consistently showed a higher content (32-35 %) than that with narrowest ring (29-33 %). These findings indicated that the eccentricity is more related to cell wall components than to secondary metabolites. Further, there is no indication with regard to the formation of tension wood.Keywords : Tectona Grandis, eccentric wood, leaning tree, chemical properties, increment rate. Intisari Tujuan penelitian ini adalah untuk mengetahui kualitas kayu cacat. Spesimen penelitian berupa 10 pohon miring yang diperoleh dari kegiatan penjarangan dari tegakan jati (Tectona grandis L.f.) di Randublatung, Jawa Tengah. Pada setiap pohon, kayu di bagian eksentrisnya dipisahkan , kemudian sampel serbuk kayu diambil pada bagian teras terluar pada kedua lebar lingkaran tahun maksimum (bagian atas pohon miring) dan pada arah yang berlawanan, yaitu yang mempunyai lebar lingkaran tahun minimum (bagian bawah pohon miring). Serbuk kayu dihaluskan sampai mencapai 40-60 mesh untuk analisis kimia. Analisis data melalui uji t pohon pada kadar ekstraktif etanol-benzena (4-12%), kadar terlarut air panas (1-3%), kadar abu (0,7-3%) dan kadar lignin terlarut asam (0,7-1,4%). Pengukuran menggunakan GC dan GC-MS, menunjukkan tidak ada beda yang mencolok pada jumlah komponen utama ekstraktif etanol-benzena. Sebaliknya, kayu dengan lingkaran tahun paling lebar secara konsisten memiliki kadar lignin Klason lebih tinggi (32-35%) dibandingkan kayu dengan lingkaran tahun sempit (29-33%). Hasil-hasil tersebut menunjukkan bahwa eksentris lebih berkaitan dengan komponen dinding sel kayu daripada zat-zat metabolism sekunder. Selanjutnya, tidak terlihat juga adanya indikasi terhadap pembentukan kayu tarik.Kata kunci : Tectona grandis, kayu eksentris, pohon miring, sifat kimia, riap tumbuh. 
Pengukuran Kadar Ekstraktif dan Sifat Warna pada Kayu Teras Jati Doreng (Tectona grandis) Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 3, No 2 (2009)
Publisher : Jurnal Ilmu Kehutanan

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Teak (Tectona grandis L.f) in certain areas of Java usually has black streaked heartwood or has been known as "doreng". In general, the color of wood is related to the kinds and amounts of extractives, therefore, black streak that appeared on the heartwood was studied by means of color measurements and the determination of extractive content. The study was made with 13 trees of black streaked heartwood and 5 trees of normal heartwood. The wood powder (40-60 mesh) was extracted successively with ethanol-benzene (1:2, v/v) for 8 h and hot water for 3 h. The used system of color measurements was CIEL*a*b* which represents brightness, redness and yellowness. The discolored wood was contained substantially more ethanol-benzene soluble extractive content (12 - 22%) than did the normal heartwood (7 - 11%). The yield differences of hot-water soluble extracts were not as pronounced. Beside the brightness (L*), the differences in redness (a*) and yellowness (b*) between the normal (L* = 51-61, a* = 4 to 7, b* = 24 to 28) and black streaked heartwood (L* = 42-51, a* = 6 to 9, b* = 20 to 25) before the extraction, were notable. The total color differences ( E*) before and after extractions, however, were not significantly differed between the discolored ( E* = 6 to 13) and normal heartwood ( E* = 5 to 11) parts. Correlation analysis revealed strong correlations between ethanol-benzene soluble extractive content with L* (r = -0.97) and b* (r = -0.94). The hot-water soluble extract was moderately correlated with a* (r = 0.54) and the difference in redness ( a*) before and after extractions (r = 0.75).Keywords: Tectona grandis, black streak, doreng, extractives, color properties.
PERUBAHAN WARNA PADA KAYU TERAS JATI (TECTONA GRANDIS) DORENG MELALUI EKSTRAKSI BERTURUTAN LUKMANDARU, Ganis
Jurnal Ilmu dan Teknologi Hasil Hutan Vol 2, No 1 (2009): Jurnal Ilmu Teknologi Hasil Hutan
Publisher : Departemen Hasil Hutan, IPB

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Black streak discolorations in the heartwood of teak (Tectona grandis) may lead to considerable economic loss. Unfortunately, the actual properties of the discolored wood remain unknown as yet. In this paper, the influence of wood extractives on black streaked heartwood color was evaluated by successive solvent extraction (n-hexane, ethyl acetate, methanol and hot-water) and color measurement (CIELab system). The change in color co-ordinates, difference in brightness (DL*), difference in redness (Da*), and difference in yellowness (Db*), between sucessively extracted and control sample was also calculated. Color of black streaked heartwood changed by any solvents, whereas n-hexane and ethyl acetate extractions apparently increased the brightness L* values. Extraction with methanol and hot water slightly affected the color differences. However, some differences were still observed in the color properties between the black streaked and normal heartwood, indicating that some substances are polymeric and tightly bound to the cell wall matrix. Some quinones : tectoquinone, tectol, lapachol, desoxylapachol and its isomer, were detected as major compounds by means of GC-MS in the n-hexane and ethyl acetate soluble extracts. The involvement of those compounds, thus, to the blackening heartwood should be investigated in the future studies.   Keywords : Tectona grandis, black streak, color, extractives
Aktivitas Antioksidan Ekstrak Metanol Kayu Mangifera indica L., Mangifera foetida Lour, dan Mangifera odorata Griff. Lukmandaru, Ganis; Vembrianto, Kristian; Gazidy, Anisa Alfiana
Jurnal Ilmu Kehutanan Vol 6, No 1 (2012)
Publisher : Jurnal Ilmu Kehutanan

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Wood and bark extracts of three mangifera species, mangga (Mangifera indica L.), pakel (Mangifera foetida Lour), and kweni (Mangifera odorata Griff.) were examined for its antioxidant activity (AOA). Each stem part was extracted with methanol (MeOH) and the crude extract was then sequentially partitioned with n-hexane, ethyl acetate (EtOAc) and n-butanol to obtain four different fractions. The antioxidant properties of the MeOH extracts and their fractions were determined by 1,1-diphenyl-2-picrylhydrazyl (DPPH) assay. This study demonstrated that the MEOH extracts from the sapwood of pakel as well as the bark of kweni significantly exhibit the strongest AOA when compared to standard antioxidants (gallic acid and catechin) at approximately 3-10 ppm in IC50 values. Among the fractions separated from the methanol extracts of those parts, EtOAc soluble fractions significantly exhibited the highest AOA properties. Qualitative phytochemical tests of EtOAc soluble fractions indicated that alkaloid and tannin could contribute to the AOA results. Total phenolic contents (TPC) of each extract were also evaluated by Folin-Ciocalteu method. Both in the crude extracts and fractions stage, only weak correlation is found between the AOA and TPC levels.Keywords : Mangifera, wood extractives, antioxidant, DPPH assay, phenolic content IntisariEkstrak dari kayu dan kulit batang tiga spesies mangifera, yaitu mangga (Mangifera indica L.), pakel (Mangifera foetida Lour), dan kweni (Mangifera odorata Griff.) telah diuji aktivitas antioksidannya (AAO). Tiap bagian batang tersebut diekstrak dengan metanol (MeOH) dan ekstrak kasarnya kemudian difraksinasi secara bertingkat dengan pelarut n-heksana, etil asetat (EtOAc) dan n-butanol untuk memperoleh 4 fraksi berbeda. Sifat anti oksidan dari ekstrak MeOH dan hasil fraksinasinya ditentukan melalui uji 1,1-diphenyl-2-picryl-hydrazyl (DPPH). Penelitian ini menunjukkan bahwa ekstrak MEOH dari gubal pakel serta kulit kweni secara nyata memberikan AAO tertinggi jika dibandingkan dengan antioksidan standar (asam galat dan katekin) dengan nilai IC50 sekitar 3-10 ppm. Dari beberapa faksi yang dipisahkan pada ekstrak MeOH di bagian-bagian tersebut, fraksi terlarut EtOAc secara nyata menunjukkan AAO tertinggi. Uji identifikasi metabolit sekunder dengan reaksi kimia secara kualitatif mengindikasikan bahwa alkaloid dan tanin berperan pada hasil pengujian AAO. Kadar fenolat total (KFT) dari tiap ekstrak juga ditentukan berdasarkan metoda Folin-Ciocalteu. Baik pada bagian ekstrak kasar maupun hasil fraksinasi, hanya korelasi yang lemah didapatkan apabila antara nilai AAO dan KFT dihubungkan.Kata kunci : Mangifera, ekstraktif, antioksidan, uji DPPH, kadar fenolat
VARIABILITY IN THE NATURAL TERMITE RESISTANCE OF PLANTATION TEAK WOOD AND ITS RELATIONS WITH WOOD EXTRACTIVE CONTENT AND COLOR PROPERTIES Lukmandaru, Ganis
Indonesian Journal of Forestry Research Vol 8, No 1 (2011): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

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Abstract

Property of natural termite resistance of teak (Tectona grandis)wood signifies one of its most important characteristics. With the purpose of understanding the variation in such resistance, four teak trees in the form of trunk (stem) from Randublatung , Central Java were randomly selected, and each wood portion sampled in radial and axial direction. Extractive content and color properties of the teak wood were also measured and correlated with properties of its natural termite resistance. Bioassay test was conducted by no-choice feeding method using Reticulitermes speratus Kolbe termites. The extractive contents were determined by successive extraction using n-hexane, ethyl acetate, and methanol, respectively. Color properties were measured with the CIELAB system. Results showed that antitermitic activity of the teak wood was affected by radial and axial position in the corresponding tree. The wood from middle part of the trees in axial direction exhibited the most resistant to termites (mean mass loss = 1- 4 mg ), while in radial direction the sapwood exhibited the least resistance ( greatest mass loss), and moving inward to the near-pith heartwood the resistance tended to decrease somewhat (slight increase of mass loss). Heartwood and sapwood part differed significantly in ethyl acetate and methanol- soluble extractive contents. Apparently, the greater the ethyl-acetate-soluble extractives (EEC) then the higher the termite resistant (lower mass loss), and conversely the greater the methanol- soluble extractive (MEC) then the lower the termite resistant ( greater mass loss). The brightness index (L*) and redness index (a*) varied significantly in radial direction, however, no significant variation was found in color properties within the heartwood. No strong degree correlation was measured between the mass loss due to termite activity and extractive content parameters. In both heartwood and sapwood, a significant negative correlation (r = -0.50) was found between the mass loss and redness (a*), while correspondingly a significant positive correlation (r = +0.54) occurred between brightness and mass loss. These occurring phenomena strongly suggested that the red colored teak wood was brought about by the moderately polar EEC (e.g. tannin, quinone, and other polyphenol) that inflicted teak-wood resistance against termite (lower mass loss), while the bright-colored teak wood was due to the highly polar MEC (e.g sugar and other soluble carbohydrate) which were conversely responsible for lowering termite resistance ( greater mass loss).
Studi Komponen Kimia Kayu Eucalyptus pellita F. Muell dari Pohon Plus Hasil Uji Keturunan Generasi Kedua di Wonogiri, Jawa Tengah Fatimah, Siti; Susanto, Mudji; Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 7, No 1 (2013)
Publisher : Jurnal Ilmu Kehutanan

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Eucalyptus pellita F. Muell (E. pellita) is one of the fast growing species, which is being developed through tree breeding program. The development of this species had produced good results in the genetic growth characteristics in the first and second generation of progeny trials. The objectives of this research were determining the variation of wood chemical components, clustering and rating the plus trees to support the development program in next generation of the progeny trial, especially in pulp and paper purposes. The materials were the 61 plus trees of E. pellita trees 9-years-old from second generation of progeny trial, Wonogiri in six different provenances. The sampling used the increment borer system at 90 cm from the surface. Materials from the increment borer were milled to 40 - 60 mesh of wood powder. The wood chemical properties were tested according to ASTM standards. It included ethanol-toluene and hot-water solubles by sequential extraction as well as holocellulose, alpha-cellulose and lignin contents. Data analysis used descriptive and clustering analysis. The results showed that the range values of ethanol-toluene extractives and hot water content respectively were 1.87 - 10.92 % and 0.64 - 10.00 %. The range values of holocellulose, alpha-cellulose and lignin contents were 72.89 - 79.91 %, 41.84 - 54.85 % and 22.12 - 36.61 %, respectively. The high values of coefficient of variation were observed in extractive content levels (30,78 - 82,91 %). Based on the simple rating, which was resulted from descriptive and cluster analysis, it gave the best 13 individuals of plus trees for pulp and paper purposes. Intisari Eucalyptus pellita F. Muell (E. pellita) merupakan salah satu jenis tanaman cepat tumbuh yang sedang dikembangkan melalui program pemuliaan. Pengembangan jenis ini sudah memberikan hasil yang cukup memuaskan dari sifat pertumbuhan genetika pada uji keturunan generasi pertama dan kedua. Penelitian ini bertujuan untuk mengetahui kandungan kimia kayu, mengelompokkan dan memeringkatkan pohon plus berdasarkan komponen kimia untuk mendukung program pengembangan uji keturunan generasi berikutnya, khususnya kayu untuk pulp dan kertas. Bahan yang digunakan adalah sampel yang berasal dari 61 pohon plus E. pellita umur 9 tahun yang ditanam di uji keturunan generasi kedua Wonogiri dan berasal dari 6 provenan berbeda. Pengambilan sampel dilakukan dengan sistem bor riap pada pangkal pohon setinggi 90 cm dari permukaan tanah. Hasil bor riap digiling hingga diperoleh serbuk kayu dengan ukuran 40-60 mesh. Pengujian sifat kimia kayu mengacu pada standar ASTM. Pengujian tersebut mencakup kadar ekstraktif etanol-toluena dan air panas melalui ekstraksi berurutan, kemudian kadar holoselulosa, alfa-selulosa dan lignin. Analisis data menggunakan analisis deskriptif dan gerombol. Hasil analisis menunjukkan kisaran kadar ekstraktif etanol-toluena dan air panas secara berurutan adalah 1,87 - 10,92 % dan 0,64 - 10,00 %. Kisaran kadar holoselulosa, alfa-selulosa dan lignin adalah 72,89 - 79,91 %, 41,84 - 54,85 % dan 22,12 - 36,61% secara berurutan. Koefisien variasi yang tinggi diamati pada parameter kadar ekstraktif (30,78 - 82,91 %). Berdasarkan hasil pemeringkatan sederhana yang dilakukan melalui analisis deskriptif dan gerombol diperoleh 13 individu pohon plus terbaik sebagai bahan baku pulp.Katakunci: Eucalyptus pellita, kimia kayu, selulosa, analisis gerombol, seleksi pohon.
Pengawetan Kayu Gubal Jati Secara Rendaman Dingin dengan Pengawet Boron untuk Mencegah Serangan Rayap Kayu Kering (Cryptotermes cynocephalus Light.) Sumaryanto, Afif; Hadikusumo, Soetjipto Achmad; Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 7, No 2 (2013)
Publisher : Jurnal Ilmu Kehutanan

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The utilization of younger teakwood has a disadvantage, which is the sapwood is more susceptible to dry wood termites as it has less natural durability. Boric acid and borax are inexpensive preservatives, which contain boron as the active material. Those preservatives are also easy to be obtained as well as do not produce smells and the wood discoloration. The experiment materials were the sapwood parts from teak boards obtained from the felled trees in the community forest of Kali Bawang, Kulon Progo. A complete randomized block design was arranged in a factorial with two factors, which were the type of preservatives (boric acid and borax in 5% concentration) and duration of cold soaking (12, 24, 36, and 48 hours). To examine the durability of sample, dry wood termites (Cryptotermes cynocephalus Light) were used. The results showed that the average values of absorption, retention, and depth of penetration were 33.09 to 70.77 kg/m3, 3.81 to 10.77 kg/m3, and 2.34 to 3.86 mm, respectively. The average values of termite mortality during 2 weeks and 4 weeks were 46.33 to 53 %, 82.67 to 94.33 %. Weight reduction and degree of the damage were, 560 to 570 mg, and 30.34 to 31.27 %, respectively. By analysis of variance, there was an interaction between the type of preservatives and the duration of cold soaking factors, which affected significantly the termite mortality. Type of preservative affected significantly the absorption and penetration. Further, the duration of cold soaking affected significantly the level of absorption, retention and penetration. The application of preservatives could reduce the mass loss of specimens until 70 % as well as to give higher levels of mortality rate (87-92 %) compared to that of untreated one.Keywords: Tectona grandis L.f., sap wood, wood preservation, borax, cold soaking, Cryptotermes cynocephalus Light. IntisariPada penggunaan kayu jati umur muda, umum diketahui bahwa bagian gubal banyak diserang oleh rayap kayu kering karena keawetan alaminya yang rendah. Asam borat dan boraks merupakan salah satu pengawet yang mengandung bahan aktif boron yang murah, mudah didapat, tidak berbau, dan tidak mengubah warna kayu. Bahan yang digunakan adalah bagian gubal papan jati yang diperoleh dari tebangan jati hutan rakyat di Kecamatan Kali Bawang, Kulon Progo. Penelitian ini menggunakan rancangan acak lengkap yang disusun secara faktorial dengan dua faktor yaitu faktor jenis bahan pengawet yaitu asam borat dan boraks (konsentrasi 5 %) dan faktor lama perendaman (12, 24, 36, dan 48 jam). Rayap yang digunakan untuk pengujian keawetan contoh uji pada penelitian ini adalah rayap kayu kering (Cryptotermes cynocephalus Light.) Hasil penelitian menunjukkan kisaran hasil rerata nilai pada parameter absorbsi sebesar 33,09 – 70,77 kg/m3 , nilai retensi sebesar 3,81 – 10,77 kg/m3 , kedalaman penetrasi 2,34 – 3,86 mm, mortalitas rayap sebesar 46,33 – 53 % selama 2 minggu dan 82,67 – 94,33 % selama 4 minggu pengumpanan, pengurangan berat sampel sebesar 0,56 – 0,57 gram, serta derajat kerusakan sebesar 30,34 – 31,27 %. Hasil analisis sidik ragam menunjukkan bahwa terdapat interaksi antara faktor jenis bahan pengawet dan lama perendaman yang berpengaruh nyata terhadap mortalitas rayap. Faktor jenis bahan pengawet berbeda sangat nyata terhadap absorbsi dan penetrasi. Faktor lama perendaman berbeda sangat nyata terhadap absorbsi, retensi, penetrasi. Pemberian bahan pengawet mampu mengurangi kehilangan berat sampai sekitar 70 % serta memberi persentase kematian rayap yang lebih tinggi (87-92 %) dibandingkan gubal tanpa perlakuan.Katakunci: Tectona grandis L.f., gubal, pengawetan kayu, boraks, rendaman dingin, Cryptotermes cynocephalus Light
Studi Mutu Kayu Jati di Hutan Rakyat Gunungkidul II. Pengukuran Tegangan Pertumbuhan Marsoem, Sri Nugroho; Prasetyo, Vendy Eko; Sulistyo, Joko; Lukmandaru, Ganis
Jurnal Ilmu Kehutanan Vol 8, No 1 (2014)
Publisher : Jurnal Ilmu Kehutanan

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Trees containing large growth stresses, leads to significant losses due to split, checked and also warped. The variation of growth-stress in teak trees grown in the three community forest sites of Gunungkidul regency was observed. The released strain levels were also discussed in relation to the growth-rate and specific gravity. The strains released in the longitudinal and tangential directions were measured by the strain-gauge method. The values of longitudinal released strain at the periphery of the stem were ranged from -130.5 to -999.5 µå whereas tangential released strain were from -103 to 1411.5 µå. Some high values of longitudinal released strain indicated the presence of tension wood. Further, intra-tree variation of growth stress showed no particular tendencies among the samples. There were significant differences in the longitudinal strain as samples from Nglipar site showed the highest amounts (-628.25 + -223.73 µå). However, no significant correlation was found between the values of released strains with the growth-rate and specific gravity. The radial distributions of internal residual-stress were varied among the individuals which some trees exhibited steeper released strain gradients. Thus, it is important to reduce the gradient from pith to periphery of released-strain patterns to prevent the defect related to the growth stresses.Keywords: Tectona grandis, growth-stress, released strain, Gunungkidul, wood properties. iIntisariPohon dengan tegangan pertumbuhan yang tinggi dikhawatirkan akan mudah mengalami cacat seperti pecah, retak, dan pelengkungan. Penelitian ini bertujuan untuk mengetahui variasi nilai tegangan pertumbuhan pohon jati yang tumbuh di tiga tempat hutan rakyat Gunungkidul. Nilai pelepasan regangan juga dibahas dari hubungannya dengan kecepatan tumbuh dan berat jenis. Pelepasan regangan pada arah longitudinal dan tangensial ditentukan melalui metode strain-gauge. Nilai pelepasan regangan di permukaan batang berkisar antara -130,5 sampai -999,5 µå sedangkan nilai pelepasan regangan tangensial antara -103 to 1411,5 µå. Beberapa nilai pelepasan regangan longitudinal yang cukup tinggi mengindikasikan adanya kayu tarik. Selanjutnya, variasi dalam pohon untuk tegangan pertumbuhan menunjukkan tidak ada kecenderungan tertentu. Perbedaan nyata diamati dimana sampel dari Nglipar memberikan nilai paling tinggi (-628,25 + -223,73 µå). Meskipun demikian, tidak ada hubungan nyata yang diukur antara nilai pelepasan regangan dihubungkan dengan laju pertumbuhan dan berat jenis. Penyebaran nilai tegangan sisa internal dalam arah radial bervariasi diantara pohon satu dengan lainnya dimana beberapa sampel menunjukkan adanya perbedaan nilai pelepasan regangan yang drastis. Untuk itu, perlu dilakukan usaha untuk mengurangi perbedaan yang mencolok di nilai pelepasan regangan dari pusat ke permukaan batang untuk mencegah cacat yang berkaitan dengan tegangan pertumbuhan.Katakunci: Tectona grandis, tegangan pertumbuhan, pelepasan regangan, sifat kayu, Gunungkidul
Chemical properties of modified mahogany wood by heat treatment Lukmandaru, Ganis; Susanti, Dewi; Widyorini, Ragil
Jurnal Penelitian Kehutanan Wallacea Vol 7, No 1 (2018): Jurnal Penelitian Kehutanan Wallacea
Publisher : Balai Penelitian dan Pengembangan Lingkungan Hidup dan Kehutanan Makassar

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18330/jwallacea.2018.vol7iss1pp37-46

Abstract

Mahogany woods from community forests generally have relatively low qualities due to lack of maintenance activities and for their young harvesting stage. Heat treatment is known as wood modification method that could improve the quality of the wood. The aim of this study was to determine the interaction effect of temperature and method of heat treatment on the chemical properties of young mahogany wood. Materials used in this research were mahogany wood boards from community forest which were heat-treated using oven and steam methods performed at the temperature of 90°C, 120°C, and 150oC for 2 hours. In this research, some chemical changes were analyzed. Results of the research showed that the interaction of temperature and heat treatment method gave a significant decreasing on the pentosan amount, and hot-water extractive solubility, particularly the steaming at 150oC. The increasing temperature of heat treatment significantly decreased the content of holocellulose, α-cellulose, hemicellulose, and pH values whereas it increased lignin content,  extractives (cold-water and alcohol-benzene extractives) and solubility in 1% NaOH. Steaming method provided lower levels in the content of holocellulose, ethanol-benzene extract, cold-water solubility, and pH values compared to the oven heating. However, the steaming method over 1200C should be considered as it would reduce the wood strengths.
Sifat Fisika Mekanika dan Ketahanan Papan Partikel Bambu dengan Perekat Asam Sitrat terhadap Serangan Rayap Kayu Kering Widyorini, Ragil; Yudha, Ari Puspa; Lukmandaru, Ganis; Prayitno, Tibertius Agus
Jurnal Ilmu Kehutanan Vol 9, No 1 (2015)
Publisher : Fakultas Kehutanan Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22146/jik.10180

Abstract

Penelitian mengenai penggunaan asam sitrat sebagai agen pengikat alami masih relatif sedikit. Oleh karena itu penelitian ini difokuskan pada pengaruh jumlah asam sitrat dan suhu pengempaan terhadap sifat papan partikel bambu, termasuk ketahanannya terhadap serangan rayap kayu kering. Bahan penelitian adalah partikel bambu petung. Komposisi kimia bahan baku bambu diuji untuk kadar ekstraktif, holoselulosa, lignin, dan alfa selulosa. Faktor pada penelitian ini adalah jumlah asam sitrat (0 - 40%) berdasarkan berat kering udara partikel) dan suhu pengempaan (200 oC dan 220 oC). Sifat fisika dan mekanika papan partikel diuji berdasarkan standar pengujian JIS A 5908. Analisis menggunakan Fourier transform infrared spectroscopy (FTIR) juga dilakukan untuk mengetahui perubahan gugus ester pada berbagai jumlah asam sitrat dan suhu pengempaan. Pengujian ketahanan terhadap serangan rayap kayu kering juga dilakukan dengan menghitung nilai pengurangan berat dan mortalitas rayap setelah 6 minggu. Hasil pengujian menunjukkan bahwa interaksi kedua faktor berpengaruh nyata terhadap nilai pengembangan tebal, penyerapan air, modulus elastisitas dan modulus patah. Intensitas gugus C=O yang ditunjukkan pada puncak 1720 cm-1 semakin bertambah besar seiiring dengan semakin banyaknya jumlah asam sitrat, yang menyebabkan kekuatan perekatan dan stabilitas dimensi papan partikel menjadi semakin kuat. Kondisi optimum pada penelitian ini adalah papan partikel dengan penambahan jumlah asam sitrat 20 % pada suhu pengempaan 200 oC dengan kualitas yang dapat memenuhi standar JIS A 5908 tipe 8. Penambahan asam sitrat dapat meningkatkan mortalitas rayap kayu kering secara nyata. Penambahan 20 % asam sitrat pada suhu pengempaan 200 oC menghasilkan nilai pengurangan berat 0,9 % dan mortalitas rayap 57 %.Kata kunci: bambu petung, asam sitrat, suhu pengempaan, jumlah asam sitrat. Mechanical properties and durability against the dry termite attacks of particleboard made from bamboo with citric acid as adhesive AbstractResearch on development of citric acid as natural adhesive are still limited. Therefore this research focused on effects of citric acid content and pressing temperature on properties of particleboard made from bamboo, including its durability to the dry termite attacks. Petung bamboo particles were used as raw materials. Chemical characteristics of petung bamboo were analyzed for its extractive, lignin, holocellulose and alpha cellulose. Factors used in this research were citric acid content (0 - 40 %) based on dry weight particles and pressing temperature (200 oC dan 220 oC). Properties of the particleboard were analyzed based on Japanese Industrial Standard (JIS) A 5908 for particleboard. Fourier transform infrared spectroscopy (FTIR) analysis was used for investigating the changes of ester groups at various citric acid content and pressing temperature. The dry termite resistance was then analyzed for its weight loss and mortality after 6 weeks. The results showed that interaction between two factors affected significantly on thickness swelling, water absorption, modulus of elasticity, and modulus of rupture. Intensity of C=O groups became stronger as increasing citric acid content, providing high mechanical properties and high dimensional stability. Optimum condition in this research was achieved at 20 % of citric acid content and 200 oC of pressing temperature, which the board properties met the requirement of JIS A 5908 type 8. Increasing of citric acid content would also increase the dry termite mortality. Addition of 20 % citric acid at 200 oC of pressing temperature produced particleboard with the weight loss was 0.9 % and 57 % of the dry termite mortality.