COMPARISON OF TEAK WOOD PROPERTIES
ACCORDING TO FOREST MANAGEMENT:
SHORT AND LONG ROTATION
DWI ERIKAN RIZANTI
GRADUATE SCHOOL
BOGOR AGRICULTURAL UNIVERSITY BOGOR
STATEMENT
I declare that this thesis entitled Comparison of Teak Wood Properties According to Forest Management: Short and Long Rotation is my own work with the direction of the supervising committee and has not been submitted in any form for any college except in AgroParisTech ENGREF, France (required by Double
Degree Program). Information and quotes from journals and books have been
acknowledged and mentioned in the thesis where they appear. All complete references are given at the end of the paper.
I understand that my thesis will become part of the collection of Bogor Agricultural University. My signature below gives the copyright of my thesis to Bogor Agricultural University.
Bogor, March 2017
Dwi Erikan Rizanti
SUMMARY
DWI ERIKAN RIZANTI. Comparison of Teak Wood Properties According to Forest Management: Short and Long Rotation. Supervised by WAYAN DARMAWAN and PHILIPPE GERARDIN.
Teak (Tectona grandis L.f.) is one of the most important tropical hardwood tree species in Indonesia. It has been processed to wood furniture in large quantities to fulfill an increasing need of both local and international consumers. To satisfy the increasing demand for wood products, teak wood has been supplied from the State forests (Perhutani) and Community teak plantations. Community teak has been harvested at shorter age rotations (7–10 years) than Perhutani teak (40–60 years).
This paper discusses the characterization of technological properties of short and long rotation teak wood based on extractives contents, chemical composition, density, vessel frequency and wood porosity, swelling, water sorption isotherm, bending strength (modulus of rupture – MOR and modulus of elasticity - MOE), Brinell hardness, wettability, color changes, and decay durability.
The results show that short rotation teak had lower extractives content, lower density, higher vessel frequency and porosity, lower dimensional stability in swelling and higher change in mass values in water sorption and desorption, lower MOE, MOR, and Brinell hardness, higher and better wettability, and lower durability compared to long rotation teak. These results also show that the short rotation teak was not remarkably different in swelling, MOE and MOR, and Brinell hardness compared to long rotation teak, although it was less dense and less durable due to lower heartwood and extractives contents. Therefore, careful attention should be given to the use of short rotation teak in some wood-processing technologies.
RINGKASAN
DWI ERIKAN RIZANTI. Perbandingan Sifat-Sifat Kayu Jati Berdasarkan Pengelolaan Hutan: Rotasi Panjang versus Rotasi Pendek. Dibimbing oleh WAYAN DARMAWAN dan PHILIPPE GERARDIN.
Jati (Tectona grandis L.f.) merupakan salah satu jenis kayu tropis yang paling penting di Indonesia. Kayu jati di Indonesia diproses menjadi produk furniture
dalam jumlah besar untuk memenuhi permintaan lokal dan internasional. Untuk memenuhi peningkatan permintaan produk, kayu jati dipasok dari Hutan Negara (Perhutani) dan Hutan Tanaman Rakyat (Community teak plantations). Jati rakyat dipanen pada rotasi yang lebih pendek yaitu sekitar 7-10 tahun dibandingkan jati Perhutani (40-60 tahun).
Penelitian ini membahas karakterisasi sifat-sifat teknologi pada kayu jati rotasi panjang dan rotasi pendek berdasarkan kandungan ekstraktif, komposisi kimia kayu, kerapatan (density), jumlah vessel dan porositas kayu, swelling, water
sorption isotherm, kekuatan lentur (modulus of rupture - MOR dan modulus
elastisitas - MOE), kekerasan kayu, keterbasahan (wettability), perubahan warna, dan daya tahan terhadap jamur pelapuk.
Hasil penelitian menunjukkan bahwa jati rotasi pendek memiliki kandungan ekstraktif, kerapatan, stabilitas dimensi yang lebih rendah, dan memiliki nilai MOE, MOR dan kekerasan yang lebih rendah, serta memiliki daya tahan terhadap jamur pelapuk yang lebih rendah dibandingkan kayu jadi rotasi panjang. Jati rotasi pendek memiliki jumlah vessel yang lebih banyak dan porositas yang lebih tinggi, memiliki nilai perubahan massa yang lebih tinggi pada fenomena water sorption isotherm, keterbasahan yang lebih tinggi dan lebih baik dibandingkan dengan jati rotasi panjang. Hasil ini juga menunjukkan bahwa nilai swelling, MOE dan MOR, dan kekerasan pada jati rotasi pendek tidak sangat berbeda dibandingkan dengan jati rotasi panjang, meskipun jati rotasi pendek memiliki kerapatan yang rendah dan daya tahan terhadap jamur pelapuk yang rendah karena rendahnya porsi kayu teras dan kandungan ekstraktif pada jati rotasi pendek. Oleh karena itu, perhatian khusus perlu diberikan dalam hal penggunaan kayu jati rotasi pendek pada beberapa teknologi pengolahan kayu.
© Copyright IPB, 2017
Copyright Reserved by Law
Prohibited quoting part or all of this paper without mentioning or citing the sources. Quotation is only for educational purposes, research, writing papers, preparing reports, writing criticism, or review of an issue, and the citations will not harm the interests of IPB
Thesis
In partial fulfillment of the requirements for the degree of Master of Science
at
Bogor Agricultural University
COMPARISON OF TEAK WOOD PROPERTIES
ACCORDING TO FOREST MANAGEMENT:
SHORT AND LONG ROTATION
GRADUATE SCHOOL
BOGOR AGRICULTURAL UNIVERSITY BOGOR
2017
FOREWORD
All praise and gratitude to Allah SWT so that the author could finish this scientific work entitled Comparison of Teak Wood Properties According to Forest Management: Short Versus Long Rotation. The study is expected to provide scientific information on the short and long rotation in teak wood in Indonesia.
The special thank goes to my helpful supervisor Prof Wayan Darmawan, Prof Philippe Gérardin and Dr Stéphane Dumarçay. The supervision, advice and support that they gave truly help the progression and smoothness of my study.
My grateful thanks also go to Prof André Merlin dan Dr Béatrice George for a big contribution and advice many times during my research, Joel Hamada, Solava Salman, Dr Julien Ruelle, Clément L’hostis, Marylin Harroué for helping me to work in laboratory and for all member of Laboratoire d’Etudes et de Recherche sur le Matériau Bois (LERMAB), Université de Lorraine, Vandoeuvre-lès-Nancy Cedex, France; Crittbois ENSTIB, Epinal Cedex, France; and laboratory of wood quality INRA Champenoux, Nancy, France, Prof Meriém Fournier, Dr Holger Wernsdorfer, and for all the staffs of AgroParisTech and Université de Lorraine.
Thanks also to my beloved parents, Mr. Rizal Ependi and Mrs. Hapizoh, my sister and brothers, Youlana Hapriza, Muhammad Seriz Dimas, Muhammad Firas Banna, Faiz Ahmad Nadhif, my closest friend Rakhmad Bagus Prakoso and the whole family, for all the prayers and love. And also thanks to all master students of Science and Technology of Forest Products 2014, my best friend Nursinta Arifiani Rosdiana, my others friends Moustafa Hassan and Christ Bopenga.
Finally, I thank to Indonesian Ministry of Education “Beasiswa Unggulan
programme” for its financial support. Without the support I simply could not come
to study the Master program.
The author recognizes that this research is still far from perfect. Therefore, suggestions and constructive criticism are expected to improve this work.
Bogor, March 2017
TABLE OF CONTENTS
TABLE OF CONTENTS vi
LIST OF TABLES vi
LIST OF FIGURES vi
LIST OF APPENDIXES vi
1 INTRODUCTION 1
Background 1
Formulation 1
Objective 2
Benefits 2
2 METHODS 2
Tools and Materials 2
Data Analyzing 8
3 RESULTS AND DISCUSSION 9
Extractives Content 9
Chemical Composition 10
Density 12
Microscopic Wood Anatomy 13
Swelling 13
Water Sorption Isotherm 14
MOE and MOR 15
Brinell Hardness 16
Wettability 17
Color Changes 19
Decay Durability 20
4 CONCLUSION 21
REFERENCES 22
APPENDIXES 25
LIST OF TABLES
1 Extractives content of short rotation and long rotation teak wood obtained by successive extractions with four solvents of increasing
polarity 9
2 Major compounds identified by GCMS in the extractives of short rotation
and long rotation teak wood 11
3 Holocellulose, cellulose, hemicellulose, and lignin Klason of short
rotation and long rotation teak wood 12
LIST OF FIGURES
1 The schematic diagram of tests specimens preparation 3 2 Transverse section of long rotation (A) and short rotation teak wood
(B) 13
3 Dimensional stability of short rotation and long rotation teak wood 14 4 Sorption and desorption isotherm of short rotation and long rotation teak
wood at 20˚ C 15
5 MOE and MOR of short and long rotation teak wood 16 6 Brinell hardness of short and long rotation teak wood 17 7 Contact angle of short rotation and long rotation teak wood using water
(a) and glycerol (b) as liquid 18
8 Color changes due to irradiation at different irradiation times at the surface of long rotation (a) and short rotation teak wood (b) 19 9 Durability of long rotation and short rotation teak wood samples to the
white rot decay fungus C. versicolor and the brown rot decay fungus P.
Sanguineus 20
LIST OF APPENDIXES
1 Dichloromethane extract chromatogram of long rotation (teak a) and
short rotation teak wood (teak b) 25
2 Acetone extract chromatogram of long rotation (teak a) and short rotation
teak wood (teak b) 26
3 Toluene-Ethanol extract chromatogram of long rotation (teak a) and
1
INTRODUCTION
Background
Teak (Tectona grandis L.f.) is one of the most important tree species in tropical regions and probably the most highly-valued hardwood. It is also one of the most important tropical hardwood tree species in Indonesia. It is planted widely in Java by Perhutani, a state forest enterprise in Indonesia, which is responsible for the management of teak. The teak planted by Perhutani has been felled in age of 40 to 60 years (long rotation teak) and processed for shipbuilding, outdoor equipment, and furniture in large quantities. Due to the increasing demand for teak wood as a raw material and to satisfy it, much of teak wood supply has been from community teak plantations which planted and managed by communities and private companies not only in Java but also in other parts of Indonesia.
Community teak trees in Indonesia grow well and fast in the Indonesian regions where they are planted. However, community teak has been harvested at short age of 7 to 10 years (short rotation teak) and it can be expected to contain a high proportion of juvenile wood. In comparison with mature wood, juvenile wood is made of smaller and shorter fibers with thinner walls and larger microfibril angles, lower density, and lower strength properties (Evans et al. 2000; Koubaa et al. 2005; Clark et al. 2006; Adamopoulus et al. 2007; Gryc et al. 2011). It is well known that characteristics of juvenile wood contribute to undesirable solid wood properties (Zobel 1984). It may cause serious problems for quality products, especially veneer or solid wood products. This is due to its low bending strength and dimensional instability. Darmawan et al. (2015) also reported that short rotation teak has lower heartwood content than long rotation teak. Heartwood portion of the short rotation teak at 10 years is 40%, whereas the long rotation teak at the age of 40 years is 80%. This causes lower resistance of short rotation teak wood that would restrict its utilization to some extent although it might still be superior to many other less resistant timbers of fast growing plantations like Sengon (Paraserianthes
falcataria), and Jabon (Neolamarckia[Anthocephalus] cadamba).
Although Darmawan et al. (2015) have been doing research on short rotation and long rotation teak wood to characterize their profiles and average trends in density, shrinkage, fiber length, microfibril angle (MFA), and bending strength (Modulus of rupture - MOR and Modulus of elasticity - MOE) as a function of radial increments from pith to bark, however, little is known on their chemical composition, extractives content, wettability, color changes, and durability. Therefore, investigating and characterizing those properties will lead to better utilization of the short rotation and long rotation teak woods.
Formulation
2
Objective
The present study aims to investigate the comparison of wood properties between short rotation and long rotation teak wood and the effects of wood chemical composition on its technological properties conditioning its utilization.
Benefits
The study is expected to provide scientific information on the technological properties of short rotation and long rotation teak wood. This properties will provide the scientific development to wood science and technology. It would also be beneficial for the industry to be able selecting appropriate processing technology so that the final product has a good quality.
2
METHODS
Tools and Materials
1. Teak trees selection and tests specimens preparation
Sample trees of teak (Tectona grandis) were obtained from plantation forests managed by the state owned enterprise Perhutani, and the local community in Java, Indonesia. The plantation sites were located at East Java for the Perhutani teak (long rotation teak), and at the community forest Bogor West Java for the Community teak (short rotation teak). Differences in growing conditions (environment, genetics, and silviculture) between West Java and East Java resulted in variations in the teak growth. The sample trees which were straight stems and free from external defects, were selected to minimize tree-to-tree variation. The long rotation trees were 40 years in the age and 30 cm in average diameter at breast height level. The short rotation trees were 10 years in the age, 6-10 m in height of branch-free stem, and 24 cm in average diameter at breast height level (1.3 m above ground level). After felling the trees, one log section 2 m in length was taken from each tree at the bottom part of the stem. The sample logs were wrapped in plastic, kept cold, and maintained in the green condition before they were transported to the wood workshop for preparation of test specimens.
3
Figure 1 The schematic diagram of tests specimens preparation The samples of 200 x 100 x 20 mm3 were cut to prepare samples of 30 x 20 x 10 mm3 for swelling test (Edou Engonga 1999, 2000), samples of 200 x 20 x 5 mm3 for mechanical tests (MOE, MOR) (EN 310), samples of 200 x 20 x 20 mm3 for Brinell hardness test (EN 1534), samples of 200 x 20 x 5 mm3 for wettability test, and samples of 30 x 20 x 5 mm3 for durability test (EN 113).
2. Determination of the amount of extractives
Short rotation and long rotation teak wood samples were ground to fine sawdust before drying at 103°C. Sequential extraction of each wood powder, approximately 10 g was carried out in a Soxhlet apparatus using successively four solvents of increasing polarity: dichloromethane, acetone, toluene/ethanol (2/1, (v/v)) and water. After extraction, organic solvents were evaporated under vacuum using a rotary evaporator while water was freeze–dried. Crude extracts were stored in desiccators under vacuum for final drying and weighed to determine extractives content based on moisture-free wood powder. Dried extractives were stored in a freezer before GC–MS analyses.
3. GC-MS analysis
A Clarus 500 GC gas chromatography (Perkin Elmer) was used for this analysis. Gas chromatography was carried out on capillary column (J&W Scientific DB-5, 30 m × 0.25 mm × 0.25 µm). Two miligrams of dry extract was dissolved in 50–100 µL of N,O-bis(trimethylsilyl) trifluoroacetamide containing 1% trimethylchlorosilane (BSTFA/1% TMCS). The solution was vortex-stirred and
heated at 70 ˚C. After evaporation of the solvent, the residue was diluted in 1 mL
of ethyl acetate. The gas chromatography was equipped with electronically controlled split/splitless injection port. The injection (1 µL) was performed at 250
4
isothermal, 10 ˚C min−1 to 190 ˚C, 15 ˚C min−1 to 280 ˚C, 5 min isothermal, 10 ˚C min−1 to 300 ˚C, 14 min isothermal. Ionization was achieved by electron impact (20 or 70 eV ionization energy). Most of the components were identified by comparing the mass spectra with the NIST Library database with match and reverse match factors above 0.750.
4. Chemical composition
Holocellulose
To 2.5 g of powder, add 80 mL of hot distilled water, 0.5 mL acetic acid, and 1 g of sodium chlorite in a 250-ml Erlenmeyer flask. An optional 25-mL Erlenmeyer flask was inverted in the neck of the reaction flask to condense vapor. The mixture was heated in a water bath at 70°C. After 1 hour, 0.5 mL of acetic acid and 1 g of sodium chlorite were added. Addition of 0.5 ml acetic acid, and 1 g of sodium chlorite was repeated every hour until the residual solid material turns to white indicating the removal of most of lignin fraction. It usually takes 6 to 8 hours of reaction. Holocellulose was filtered on filter paper using a Buchner funnel until the filtrate becomes colorless, washed with acetone, dried at 103°C for 24 hours and weighed. The lignin content is determined by difference between the dry initial extracted free mass of wood and the dry holocellulose mass (Rowell 2005).
Cellulose
The cellulose was obtained by the Kurschner and Hoffner method using nitric acid in ethanol (HNO3 (16N), ethanol (95%)) (Antunes 2000). One gram of extracts free sawdust was placed in a 250 mL flask. Forty mL of ethanol and 10 mL of nitric acid was added and the mixture placed under reflux at 100˚C. After one hour, the alcoholic nitric acid solution was discarded and a fresh volume was added. This operation was repeated one additional time. After the third hour of hydrolysis, the cellulose was washed with ethanol, filtered, dried in an oven at 103˚C for 24 hours and weighed. The cellulose content is calculated using the following formula:
Cellulose content (%) = (cellulose mass / initial mass sawdust) x 100
Hemicellulose
Hemicellulose content was obtained by difference between holocellulose content and cellulose content. The hemicellulose content is calculated using the following formula:
Hemicellulose content (%) = Holocellulose (%) – Cellulose (%)
Lignin
5 Sulfuric acid(97.5%) of 1.5 mL was added to the sawdust. The tubes were closed and placed in a water bath equipped with a stirring system at 30˚C for 1 hour. After this period, the mixture was diluted with 42 mL of distilled water to obtain a sulfuric acid concentration of 30%. The tubes were closed and autoclaved for 1 hour and half at 120˚C. After autoclaving, the mixture was diluted with 100 mL of distilled water and filtered on a Buchner funnel. The black residue of Klason lignin obtained was dried at 103˚C for 48 hours until constant mass. Klason lignin content is determined by the following formula:
Klason lignin content (%) = (Mass of lignin / 0.175) x 100
5. Density measurement
Density was calculated as the air-dried mass (moisture content 12-15%) divided by the air-dried volume of the sample, using the following equation:
ρ= ��
where ρ is the density of the wood (kg/m³), m is the air-dried mass (kg), and V is the air-dried volume (m³). Sample dimensions were measured along the radial, tangential, and longitudinal directions using a 0.01-mm precision caliper in air-dried condition.
6. Microscopic wood anatomy measurements
Thin transversal sections (12 μm in thickness) were prepared by using a sliding microtome equipped with a tungsten blade. Observations were made on undamaged thin slice after coloration with Safranin 1% and Blue Astra 1% were used in order to easily study the cellstructure. Digital images of transverse sections were captured with a digital camera mounted on photonic microscope and analyzed with the ImageJ 1.47s software to determine the vessel area, vessel frequency (vessel number per unit area), and wood porosity.
7. Swelling test
The method was performed according to Edou Engonga (1999) and Edou Engonga (2000). Six replicates (30 x 20 x 10 mm3) of short and long rotations teak wood were dried for 48 hours at 103 oC. Test blocks were soaked in water in a beaker. The beaker was placed in a desiccator and subjected to vacuum (30 mbar) for 1 hour. The samples were left submerged in water for one day. After this period, the water contained in the beaker was changed and cycle of soaking repeated four times with change of water between each cycle. Samples were then removed from water and their dimensions measured to obtain wet volume. Volumetric swelling of wood samples is calculated with the following formula:
6
where S is swelling of wood, VW is wet volume of wood, and VD is dry volume of wood.
8. Water sorption isotherm
Isotherms were performed using a dynamic gravimetric water sorption analyzer from Surface Measurement Systems (DVS-Intrinsic) on small teak chips previously extracted (precise solvent) or non-extracted samples (Simo-Tagne et al. 2016). An initial mass of approximately 10 mg of each sample was used for each measurement. The sorption cycles applied started from 0% RH at 20°C. Samples were maintained at a constant RH level until the weight change per minute (dm/dt) value reached 0.0005% per minute.
9. Mechanical tests (MOE and MOR)
MOE and MOR were determined with samples of 200 x 20 x 5 mm3 according to EN 310 by a three point bending device INSTRON 4467 universal testing machine. MOE (N/mm2) of each sample is calculated with this following formula:
Em = [I13 (F2–F1)] / [4 b t3 (a2–a1)]
where I1 is the distance between the centers of support in millimeters, b is the width of the sample in millimeters, t is the thickness of the sample in millimeters,
F2 – F1 is the increase in load in newton, on the cross section of the load-deformation curve, F1 should be approximately 10% and F2 approximately 40% of the breaking load, a2–a1 is the increase if the arrow at mid-length of the test sample (corresponding to F2–F1). MOR (N/mm2) of each sample was calculated with this following formula:
fm = (3 FmaxI1) / (2 b t2)
where Fmax is the breaking load in newton. Six replicates were used for each kind of teak wood.
10. Brinell hardness test
This test was conducted according to EN 1534 on the test samples with a dimension of 200 x 20 x 20 (L, T, R) mm3. The test was performed on each of the tangential and radial faces of the specimens. The ball diameter is 10 mm; a force was applied gradually until its value reached 1960 Newton in twenty seconds, this force was maintained 30 seconds, then slowly discharged. The measure of the depression showed us the Brinell hardness. The Brinell hardness is then obtained using the following formula:
7 where HB is Brinell hardness (N/mm2), F is the nominal force (N), D is the ball diameter, and d is the diameter of the residual impression (mm).
11. Contact angle measurements
Contact angle of teak wood was measured by optic method using a Krüss model DSA10 at room temperature and humidity with water and glycerol as test liquids. Ten drops of liquid were used for each wood sample. For each drop, eleven contact angle measurements were performed automatically (one measurement each two seconds).
12. Color measurement
Samples were exposed in a QUV accelerated weathering tester from Q-Lab (USA) for 60 hours. Cycle 1 of ASTM G154-2012 Standard test method “Standard Practice for operating Fluorescent Ultraviolet (UV) Lamp Apparatus for exposure of non-metallic Materials” was used. An UV-A 340 lamp was used for the irradiation at 0.89W/m2/nm to simulate the UV portion of the solar spectrum.
Color changes were analysed using a reflectance spectrophotometer: X-Rite spectrophotometer. CIEL*a*b* color scale was used. The CIEL*a*b* system is one of the systems used to quantify color. The L* axis represents the lightness and varies from 100 (purewhite) to zero (pure black). a* and b* are the chromaticity
coordinates: +a* is for red, −a* for green, +b* for yellow and -b* for blue. Zero (0) is grey. The overall colour differences (delta E) were calculated using the following Eq. :
ΔEab*= [(ΔL*)² + (Δa*)² + (Δb*)²]1/2
where ΔL*, Δa* and Δb* are the difference of initial and final values. A low ΔE* value corresponds to a low colour difference.
13. Decay durability test
Resistance to decay was evaluated with a method derived from EN 113 standard. In brief, white rot fungi Coriolus versicolor (Cv) and brown rot fungi
Pycnoporus sanguineus (Ps) were inoculated on sterile culture medium prepared
from malt (40 g) and agar (20 g) in distilled water (1 L) in 9cm Petri dishes and cultivated in an incubator at 22°C temperature and 70% of relative humidity for 7 days. After colonization of all the surface of Petri dishes by the mycelium, three short rotation or long rotation teak samples or beech samples were put in each petri dish and then incubated for another 12 weeks. Twelve replicates of sampeles for each fungus tested. The weight loss (WL) due to degradation by fungus was calculated with the following equation:
8
where WL is the weight loss ratio (%) and M0 and M1 are dry mass of the samples before and after exposure to fumgus, respectively.
Data Analyzing
9
3
RESULTS AND DISCUSSION
Extractives Content
Extractives contents were obtained by extraction using successively four solvents of increasing polarity. The results of extractives contents of short rotation and long rotation teak wood are presented in Table 1.
Table 1 Extractives content of short rotation and long rotation teak wood obtained by successive extractions with four solvents of increasing polarity.
Solvent Extractives content (%)
Long rotation teak Short rotation teak
Dichloromethane 2.8 0.5
Acetone 1.1 0.3
Toluene:Ethanol (2:1) 1.6 0.4
Water 2.5 2.5
Total 8.0 3.7
Extractives contents of long rotation teak wood (8.0%) was higher than those of short rotation teak wood (3.7%). The long rotation teak contained more dichloromethane, acetone, toluene ethanol-soluble extractives content than short rotation teak did (Table 1), but almost the same in water-soluble extractives (2.5%). Long rotation teak had higher extractives contents than short rotation teak, this was due to higher heartwood and mature wood contents in long rotation teak. Darmawan
et al. (2015) reported that long rotation teak has more mature wood and higher
heartwood contents than short rotation teak. Otherwise, short rotation teak has more juvenile wood and higher sapwood contents. In other studies, it was reported that extractives contents of heartwood are higher compared to sapwood both for long rotation and short rotation teak wood (Wijayanto 2014 and Miranda 2011). However, extractives contents in this study was different from extractives contents reported by Wijayanto (2014). The extractives contents in heartwood and sapwood for the long rotation teak (64 years) are 12.65% and 6.84% respectively. Another result was reported by Miranda et al. (2011), the total extractives contents in heartwood and sapwood of teak wood (50-70 years) from East Timor are 10.0% and 9.2%, respectively. Differences extractives contents can be influenced by age rotation (Lukmandaru and Takahashi 2008), growth location, the type of solvent and extraction techniques (Moya et al. 2014).
10
during the duramination process in teak wood (Miranda et al. 2011, Niamké et al. 2011, Lukmandaru and Takahashi 2008). Water-soluble extractives content in sapwood is high because water can dissolve carbohydrates, protein, and tannin which are high in sapwood. Niamké et al. (2011) reported that high sapwood extractives contents dissolved in polar solvents caused by the presence of nonstructural carbohydrates (non-structural carbohydrates (NSC)). NSC in the form of starch increased dramatically from heartwood to sapwood. Heartwood is generally have a lower starch content (Fengel and Wegener 1995). High starch content in wood will contribute negatively to wood durability against wood-destroying organisms. Wood high starch content will be favored by organisms that utilize starch as food sources.
Chemical Composition
Chemical composition of short rotation and long rotation teak wood extractives
GCMS analysis of extractable with dichloromethane shows that squalene was the major component for this solvent and for short rotation and long rotation teak wood (Table 2). Wijayanto (2014) reported the same result for teak wood extracted with dichloromethane. Windeisen et al. (2003) also reported the same result with petroleum (nonpolar solvent), and Lukmandaru and Takahashi (2009) which shows that squalene is the main substance in ethanol-benzene extract.
11 Table 2 Major compounds identified by GCMS in the extractives of short rotation
and long rotation teak wood Long rotation
1,2,3,4,4a,9,10,10a-octahydrophenanthrene 669 3.5
17.35 9,10-Anthracenedione, 2-methyl-
(Techtoquinone) 893 4.5
21.65 Squalene 909 46.7
27.01 Stigmasterol trimethylsilyl ether (Silane) 852 4.2
27.78 β-Sitosterol trimethylsilyl ether (Silane) 794 9.6
Acetone
11.80 1,2-Tetradecanediol 627 9.3
11.99
5,5-Dimethyl-1-oxa-5-silacyclononanone-9 566 6.1
16.68
4a-Methyl-1-methylene-1,2,3,4,4a,9,10,10a-octahydrophenanthrene 650 4.6
17.38 9,10-Anthracenedione,
2-methyl-(Techtoquinone) 874 14.5
17.51 Cyclononasiloxane, octadecamethyl- 721 5.1
Toluene : Ethanol
11.88 1,2-Tetradecanediol 658 31.5
16.64 Octasiloxane,1,1,3,3,5,5,7,7,9,9,11,11,13,1
3,15,15-hexadecamethyl- 745 4.0
16.83 Phenol, 4-tert-butyl-2-phenyl- 769 6.4
17.51 9,10-Anthracenedione,
2-methyl-(Techtoquinone) 651 12.8
19.77 Cyclooctasioxane, hexadecamethyl- 810 5.9
Short rotation
27.02 Stigmasterol trimethylsilyl ether (Silane) 845 6.5
27.72 Lanosta-8,24-dien-3-one 467 5.5
28.61 Squalene 758 7.1
27.81 β-Sitosterol trimethylsilyl ether (Silane) 732 15.1
Acetone
32.52 Benzenepropanoic acid,
3,5-bis(1,1-dimethylethyl)-4-hydroxy-, octadecyl ester 613 30.0
14.62 1-Nonadecene 922 10.6
16.24 1-Nonadecene 922 8.2
17.30 Trisiloxane, octamethyl- 595 5.4
31.87 4-tert-Butylcalix[4]arene 468 4.8
Toluene : Ethanol
17.31 2-tert-Butyl-6-methylphenol, trimethylsilyl
ether 607 4.1
19.77 Linoleic acid, 2,3-bis-(O-TMS)-propyl
ester 561 6.1
23.41 Oxirane, [(hexadecyloxy)methyl]- - 12.7
24.78 Oxirane, [(hexadecyloxy)methyl]- - 5.6
31.89 2 β,4a
12
Chemical composition of short rotation and long rotation teak wood
The chemical composition of short rotation and long rotation teak wood is shown in Table 3.
Table 3 Holocellulose, cellulose, hemicellulose, and lignin Klason of short rotation and long rotation teak wood
Long rotation teak Short rotation teak
Holocellulose (%) 68.53 67.50
Cellulose (%) 49.18 48.80
Hemicellulose (%) 19.35 18.70
Lignin Klason (%) 32.19 35.53
Long rotation teak (less juvenile wood and more heartwood contents) contained more holocellulose, cellulose, and hemicellulose contents and lower lignin content compared to short rotation teak (more juvenile wood and lower heartwood content). However, the chemical composition of short rotation teak was not remarkably different compared to long rotation teak (Table 3). Differences in chemical composition between short rotation and long rotation teak can be influenced by many factors such as location where teak grows, climate, and its location in the wood (Dumanauw 1990). Another result reported by Miranda et al. (2011), holocellulose and cellulose contents in heartwood of 50-70 years teak wood (holocellulose 57.5% and cellulose 44.6%) from East Timor was higher than sapwood (holocellulose 56.2% and cellulose 43.7%), but their lignin contents was relatively the same (32.2% in heartwood and 32.4% in sapwood). According to Fengel and Wegener (1995), in general, sapwood contains more lignin compared to heartwood. Thomas (1984), Kininmonth (1986), and Zobel and Sprague (1998) stated that juvenile wood has higher lignin and lower cellulose content.
Density
13 Microscopic Wood Anatomy
Vessel frequency in cross section was classified according to the number of vessels per mm². There is a different value in the frequency of vessel cell between long rotation and short rotation teak wood. Long rotation teak wood had a lower vessel frequency values (average 4.2 vessels/mm²) compared to short rotation teak wood (average 5.5 vessels/mm²). Martawijaya et al. (2005) found the vessel frequency of long rotation teak wood in the range from 3-7 vessels per mm². Utomo (2012) also found the vessel frequency of long rotation teak wood in the range 4-8 vessels per mm². This vessel frequency value is one of important factors which could determine the dimensional stability and wettability of teak wood that affect the quality of wood.
Figure 2 Transverse section of long rotation (A) and short rotation teak wood (B) The porosity average value of both short rotation teak and long rotation teak wood were 45.28 ± 2.5 % area and 36.21 ± 1.8 % area, respectively. The values of porosity showed the proportion of voids in the growth ring of the wood. Long rotation teak wood had a lower porosity compared to short rotation teak wood. Percentage of porosity can affect to mechanical properties of wood. High porosity of wood tends to reduce strength.
Swelling
The volumetric swelling for long rotation and short rotation teak wood is presented in Figure 3. The mean values of swelling for long rotation and short rotation teak wood were 7.2% and 8.4% respectively. These results indicate that the long rotation teak with higher density, lower vessel frequency, and lower porosity would have a lower volumetric swelling than short rotation teak, which leads to improved dimensional stability. The higher volumetric swelling for the short rotation teak suggests that careful attention should be given for the use of short rotation teak in some wood-processing technologies (e.g. production of sawn timber and drying, plywood, LVL).
A
14
Figure 3 Dimensional stability of short rotation and long rotation teak wood These results also show that the long rotation teak with higher extractives contents affected wood increasing stability. Miller 1999 stated that extractives contents may also affect wood increasing stability in changing moisture conditions and increasing weight slightly. High extractives contents cause a decrease in the hygroscopic properties of some species of wood, therefore this may be one of the factors that led to an increase in the dimensional stability of wood (Skaar 1972). According to Haygreen and Bowyer (2003), extractives content in the wood can affect wood permeability, level of ease of water into the wood.
Water Sorption Isotherm
The full sorption–desorption isotherm is presented in Figure 4 for short rotation and long rotation teak wood. Sorption–desorption isotherms were obtained for 4 different samples: long rotation teak wood with and without extractives; short rotation teak wood with and without extractives. Figure 4 shows the change in mass values in sorption and desorption for the short rotation and long rotation teak wood
at 20˚ C.
The sorption curves were higher than the desorption curves for any type of samples. For any given water activity, the change in mass of the samples increased as the relative humidity increased. The change in mass values of the long rotation teak wood, either sorption or desorption, were slightly lower than the short rotation teak wood values. This indicate that long rotation teak has higher stability in change in mass compare to short rotation teak due to lower vessel frequency and porosity in long rotation teak. Lower vessel frequency and porosity of teak wood increased its stability in either sorption and desorption and decreased hygroscopicity.
15
Figure 4 Sorption and desorption isotherm of short rotation and long rotation teak wood at 20˚ C
These results also show that the teak samples without extractives (extracted) had a greater change in mass values than the samples with extractives. These results indicate that the existence of extractives in wood effected change in mass values. Various studies have shown that the extractives content has a role in the sorption process, as wood with extractives has lower EMC and lower change in mass (Wangaard and Granados 1967; Hernandez 2007).
MOE and MOR
Mean MOE values for long rotation and short rotation teak wood calculated in this study were 12861.8 N/mm² and 9929.3 N/mm², respectively, and their mean MOR values were 118.9 N/mm² and 97 N/mm², respectively (Figure 5). Darmawan
et al. (2015) found that the mean MOE values for long rotation teak and short
rotation teak wood are 12759 N/mm² and 8323 N/mm², respectively, and their mean MOR values are 102 N/mm² and 77 N/mm², respectively. Martawijaya et al. (2005) also found that the MOE and MOR of long rotation teak are 12514 N/mm² and 101 N/mm², respectively. The MOE and MOR values of short rotation teak wood in this study were lower than those of the long rotation teak wood. Concerning wood properties, juvenile core is reported to be of lower density, lower stiffness (MOE) and strength (MOR), higher grain angle, higher longitudinal shrinkage, higher incidence of reaction wood (Evans et al. 2000; Koubaa et al. 2005; Clark et al. 2006; Adamopoulus et al. 2007; Gryc et al. 2011; Lachenbruch et al. 2011). Miranda et al. (2011) reported that the mean MOE and MOR values of teak wood (50-70 years old) from East Timor are 10684 N/mm² and 141 N/mm², respectively. Several authors have also found that differences in mechanical and physical properties of juvenile wood and mature wood in teak were negligible (Baillères and Durand 2000). Kokutse et al. (2004) also reported that MOE value for 70 years teak
16
is 16704 N/mm². The lower MOE and MOR suggest that careful attention should also be given for the use of short rotation teak for construction purposes.
Figure 5 MOE and MOR of short rotation and long rotation teak wood Although the short rotation teak had lower MOE and MOR values, however its values are greater than others fast growing species such as Jabon (MOE 6668 N/mm²; MOR 67.7 N/mm²) (Martawijaya et al. 1989) and Sungkai (MOE 8237 N/mm²; MOR 55.7 N/mm²) (Martawijaya et al. 2005). This indicate that the utilization of short rotation teak in Indonesia is still appropriate for some indoor applications.
Brinell Hardness
The results of Brinell hardness test for short rotation and long rotation teak wood are shown in Figure 6. Values presented were the average on radial and tangential penetrations. Long rotation teak wood had a greater Brinell hardness mean values than short rotation teak wood (35.2 N/mm² and 27.9 N/mm², respectively). Martawijaya et al. (2005) found that the Brinell hardness mean value of long rotation teak was 41.3 N/mm². Wahyudi et al. (2014) also found that the Brinell hardness mean values of short rotation teak in 4 years old was 20.8 N/mm².
12861.8
Long rotation teak Short rotation teak
118.9
17
Figure 6 Brinell hardness of short rotation and long rotation teak wood The greater Brinell hardness values of long rotation teak wood were due to the higher density of long rotation teak wood than short rotation teak wood. The wood with high density indicating that the mass of wood is denser than that wood with low density. Dwianto and Marsoem (2008) reported that density of wood is one of the important physical properties of wood that can affect the mechanical properties such as MOE, MOR and hardness.
Wettability
Contact angles for long rotation and short rotation teak wood are presented in Figure 7(a) and 7(b). Contact angle is one of the parameters generally used to define wettability (Walinder 2000; Bryne and Walinder 2010). Contact angle value was used in this study to investigate the wettability. In this study, water and glycerol were used for measurement of contact angle for long rotation and short rotation teak with and without extractives.
Figure 7(a) shows that contact angle using water as liquid was greater for long rotation teak with and without extractives compared to short rotation teak. There was a great difference for the initial and final contact angles measured for long rotation and short rotation teak. Due to the high water permeability of short rotation teak, the contact angle on its surface decreased rapidly with time. Contact angles for water on the surface of short rotation teak with and without extractives were 13.2° and 4.4˚ at the beginning (t= 0 s), respectively, then the contact angles were observed to be 0° both for short rotation teak with and without extractives at t= 19 s. Otherwise, the contact angle of water on the surface of long rotation teak was prominently larger from beginning (t= 0 s) up to end (t= 19 s) compared to the contact angle of the short rotation teak.
Figure 7(b) also shows that relatively the same tendency of contact angle was generated by glycerol liquid in the surface of long rotation and short rotation teak. Long rotation teak with extractives had the greatest contact angle value, followed by short rotation teak with extractives, long rotation teak without extractives, and short rotation teak without extractives. However, there was no great changes of
Long rotation teak Short rotation teak
18
rotation and short rotation teak. The small changes in contact angle of the glycerol on the surface of teak wood compared to water indicate that the distribution and penetration of glycerol were very slow. This is due to glycerol had a higher viscosity compared to water. In addition, surface tension of glycerol is lower (64.00 mN/m) compared to surface of water (72.80 mN/m) (Kaelble 1971; Wu et al. 1995). There are also many factors (such as surface tension phenomena and viscosity of liquids) that influence penetration (Huang et al. 2012). Gavrilovic-Grmusa et al. (2012) stated that the properties of the coatings (e.g., viscosity, type of coating, temperature, and surface tension) also influence the wettability.
(a) (b)
Figure 7 Contact angle of short rotation and long rotation teak wood using water (a) and glycerol (b) as liquid
The results in figure 7 show that teak wood without extractives had lower contact angle (better wettability) compared to teak wood with extractives. Higher contact angle for the wood with extractives is considered to be caused by higher hydrophobicity on the surface of the long rotation teak compared to short rotation teak as the long rotation teak contained higher fractions of low polarity compounds extracted with dichloromethane (2.8%) (Table 1). Low polarity compounds of extractives such as fats, wax, and resin tend to be hydrophobic, therefore its presence in the wood will reduce the ability on spreading and penetration of liquids into the wood surface.
These results also indicate that short rotation teak had lower contact angle (better wettability) compared to long rotation teak. This is due to the short rotation teak had a lower extractives content compare to long rotation teak (Table 1). Extractives in wood inhibited the liquids into the wood. According to Uprichard (1993); Ghofrani et al. (2016); and Hakkou et al. (2005) amount of extractives affect
19 the wettability of wood surfaces and thereby the application of paints and adhesives. Besides that, the effect of wood species on the spreading and penetration could strongly depend on the texture and structure of the wood surface. The short rotation and long rotation teak wood have well-known differences in texture and structure. The short rotation teak wood is different in vessel and porosity from the long rotation teak wood. Vessel area of short rotation teak (average 5.5 vessels/mm²) was larger than that of long rotation teak (average 4.2 vessels/mm²) and also the porosity value of short rotation teak was greater. Therefore, the short rotation teak wood is considered to have higher liquid spreading and penetration than that of the long rotation teak wood.
Color Changes
Figure 8 presents the variation of ∆L*, ∆a*, ∆b*, and ∆E* with irradiation
time. The ∆L*, ∆a*, ∆b*, and ∆E* of long rotation and short rotation teak wood increased during irradiation. The increase in ∆b* in this research indicate that the lignin on teak wood suffered a degradation during UV irradiation. In another study, it was reported that the increase in the value of ∆b* can be attributed to the formation of quinones and quinoide-like structures due to depolymerisation and oxidation of lignin involving free radicals in this process (Hon 2001). Phenolic groups react rapidly and form phenolic radicals (Pandey 2005 and Leary 1968). It also appears in Figure 8 that the value of ∆L* on long rotation teak changed in more abruptly compared to the short rotation teak wood. This indicate that long rotation teak was more sensitive in color changes compared to short rotation teak due to higher extractives content in long rotation teak.
(a) (b)
Figure 8 Color changes due to irradiation at different irradiation times at the surface of long rotation (a) and short rotation teak wood (b)
20
The color of long rotation and short rotation teak wood tended to gradually change after UV irradiation. Thus, upon irradiation, both the long rotation teak and short rotation teak wood tend to lightened, verdant and yellowed after 60 hours. The variation of extractives or chemical composition of lignin can explain the wood colour variation of heartwood. For example, redness (a∗) and lightness (L∗) are correlated with extractive content, while yellowness (b∗) is primarily related to the photochemistry of the major wood components, especially lignin (Gierlinger et al. 2004). According to Hon et al. (2000) lignin is mainly degraded due to its capacity to absorb light in short wave length. Muller et al. 2003 and Hon et al. 2000 stated that changes in wood colour reflect chemical changes during irradiation and the appearance of new chromophoric structures.
Decay Durability
The resistance of the teak wood samples to the white rot decay fungus
Coriolus versicolor and the brown rot decay fungus Pycnoporus sanguineus is
presented in Figure 9.
Figure 9 Durability of long rotation and short rotation teak wood samples to the white rot decay fungus C. versicolor and the brown rot decay fungus P. Sanguineus
These results show that there was a great difference for the weight losses measured for long rotation and short rotation teak, either for C. versicolor or P.
sanguineus. The weight losses of long rotation teak wood samples (0.18% for Cv
and 0.15% for Ps) were lower than short rotation teak wood samples (19.10% for
Cv and 17.13% for Ps), while beach wood samples presented the highest weight losses of 23.18% for Cv and 20.23% for Ps. The lower weight loss of long rotation teak wood indicate that it was more durable than short rotation teak wood. This is due to the high content of extractives in long rotation teak wood compared to short rotation teak wood (Table 2). According to Tsoumis (1999), extractives content can affect the wood properties such as color and natural durability of wood. The high content of extractives can increase its natural durability against wood-destroying.
0.18
Long rotation teak Short rotation teak Beech
21 The high content of heartwood in long rotation teak could also affect the natural durability of the teak wood. Miller (1999) stated that in some species, heartwood extractives make the wood resistant to fungi or insect attack. However, none of the sapwood of any species is resistant to decay.
Type of compounds and compositions in the teak wood extractives also affected the natural durability of the teak wood. The presence of tectoquinone in larger amounts in long rotation teak extracts increased its natural durability against wood-destroying compared to the short rotation teak wood. Thulasidas and Bhat (2007) and Lukmandaru and Ogiyama (2005) also noted that tectoquinone are the compounds that responsible for teak resistance to damage by the brown-rot fungus. Brown-rot fungi may reduce mechanical properties of wood. Unlike mold and stain fungi, wood-destroying (decay) fungi seriously reduce strength by metabolizing the cellulose fraction of wood that gives wood its strength. Miller (1999) stated that decay has the greatest affect on thoughness, impact bending, and work to maximum load in bending, the least effect on shear and hardness, and an intermediate effect on other properties of wood.
4
CONCLUSIONS
This study results indicate that long rotation teak contains higher amounts of extractives (the tectoquinone) than the short rotation teak wood. The extractives contents affect the durability, dimensional stability, and wettability of teak wood. The long rotation teak wood with higher content of extractives increase its natural durability against wood-destroying, increase stability in changing moisture conditions, and decrease wood permeability.
22
REFERENCES
Adamopoulos S, Passialis C & Voulgaridis E. 2007. Strength properties of juvenile and mature wood in black locust (Robinia pseudoacacia L.). Wood Fiber Sci. 39:241–249.
Antunes CSA, Bietti M, Salamone M, Scione N. Early stage in the TiO2- photocatalyzed degradation of simple phenolic and non-phenolic model compounds. Journal of Photochemistry and Photobiology A: Chemistry. 163:453-462.
Baillères PH, Durand PY. 2000. Non-destructive techniques for wood quality assessment of plantation-grown teak. Bois Forêts Trop. 263:17–29.
Bhat KM, Priya PB, Rugmini P. 2001. Characterisation of juvenile wood in teak.
Wood Sci Technol. 34:517–532.
Bryne L, Walinder M. 2010. Ageing of modified wood. Part 1: Wetting properties of acetylated, furfurylated, and thermally modified wood. Holzforchung. 64:295-304.
Clark A, Daniels RF, and Jordan L. 2006. Juvenile mature wood transition in loblolly pine as defined by annual radial increment specific gravity, proportion of latewood, and microfibril angle. Wood Fiber Sci. 38:292–299. Darmawan W, Nandika D, Sari RK, Sitompul A, Rahayu I, and Gardner D. 2015.
Juvenile and mature wood characteristics of short and long rotation teak in Java. IAWA Journal. 36(4):429-443. doi: 10.1163/22941932-20150112. Dumanauw JF. 1990. Mengenal Kayu. Yogyakarta (ID): Kanisius.
Edou Engonga P, Schneider R, Gérardin P, Loubinoux B. 1999. Chemical modification of wood with perfluoroalkanols and MDI. Holzforschung. 53(3):272-276.
Edou Engonga P, Schneider R, Gérardin P, Loubinoux B. 2000. Preparation and dimensional stability of wood grafted with alkyl chains. Holz als Roh-und
Werkstoff. 58:284-286.
European Standard. 1993. EN 310, Wood-based panels – Determination of modulus of elasticity in bending and of bending strength.
European Standard. 1996. EN 113, Wood preservatives–Test method for determining the protective effectiveness against wood destroying basidiomycetes – Determination of the toxic values.
European Standard. 2010. EN 1534, Wood flooring – Determination of resistance to indentation – Test method.
Evans J, Senft JF, and Green DW. 2000. Juvenile wood effect in red alder: analysis of physical and mechanical data to delineate juvenile and mature wood zones.
For Prod J. 50:75–87.
Fengel D, Wegener G. 1995. Wood: Chemistry, Ultrastructure, Reaction. Yogyakarta (ID): Gadjah Mada University Press.
Gavrilovic-Grmusa I, Dunky M, Miljkovic J, Djiporovic M. 2012. Influence of the viscosity of UF resins on the radial and tangential penetration into Poplar wood and the shear strength of adhesive joints. Holzforschung. 66:849-856. Ghofrani M, Mirkhandouzi FZ, Ashori A. 2016. Effects of extractives removal on
the performance of clear varnish coatings on boards. Journal of Composite
23 Gierlinger N, Jacques D, Grabner M, Wimmer R, Schwanninger M, Rozenberg P, Pâques LE. 2004. Colour of larch heartwood and relationships to extractives and brown-rot decay resistance. Trees Struc Funt. 18:102–108.
Gryc V, Vavrcik H, and Horn K. 2011. Density of juvenile and mature wood of selected coniferous species. J For Sci. 57:123–130.
Hakkou M, Pétrissans M, Zoulalian A, Gérardin P. 2005. Investigation of wood wettability changes during heat treatment on the basis of chemical analysis.
Polymer degradation and stability. 89:1-5.
Haygreen JG, Bowyer JL. 2003. Forest Product and Wood Science: An
Introduction. 3rd Edition. Iowa: Iowa State University Press/Ames.
Hernandez RE. 2007. Moisture sorption properties of hardwood as affected by their extraneous substances, wood density, and interlocked grain. Wood Fiber Sci. 39:132–145.
Hon DNS. 2001. Weathering and Photochemistry of Wood. New York (US). 512-546.
Huang X, Kocaefe D, Kocaefe Y, Boluk Y, and Pichette A. 2012. Changes in wettability of heat-treated wood due to artificial weathering. Wood Sci and
Technol. 46(6): 1215-1237.
Kaelbled H. 1971. Physical Chemistry of Adhesion. Wiley-Interscience. New York, London, Syndey, Toronto. 507 pp.
Kokutse AD, Baillères H, Stokes A, Kokou K. 2004. Proportion and quality of heartwood in Togolese teak (Tectona grandis L.f.). For Ecol Manag. 189:37– 48.
Koubaa A, Isabel N, Shu Yin Z, Beaulieu J & Bousquet J. 2005. Transition from juvenile to mature wood in black spruce (Picea mariana (Mill. B.S.P.). Wood
Fiber Sci. 37:445–455.
Lukmandaru G and Ogiyama K. 2005. Bioactive compounds from ethyl acetate extract of teakwood (Tectona grandis L.f.). Wood Biomass. 6:413-416. Lukmandaru G and Takahashi K. 2008. Variation in the natural termite resistance
of teak (Tectona grandis Linn. fil.) wood as a function of tree age. Ann For Sci. 65:708.
Lukmandaru G and Takahashi K. 2009. Radial distribution of quinones in plantation teak (Tectona grandis Linn.fil.). Ann For Sci. 66(6):605. doi: 10.1051/forest/2009051.
Lukmandaru G, Ashitani T, Takahashi K. 2009. Color and chemical characterization of partially black- streaked heart-wood in teak (Tectona
grandis). J For Res. 20:377–380.
Martawijaya A, Kartasujana I, Kadir K, and Prawira S. 1989. Atlas Kayu Indonesia Jilid II. Bogor (ID):Forest Products Research Institute.
Martawijaya A, Kartasujana I, Kadir K, and Prawira S. 2005. Atlas Kayu Indonesia.
Bogor (ID):Forest Products Research Institute.
Miller RB. 1999. Wood Handbook: Wood as an Engineering Material. America (US): The Forest Products Society.
Miranda I, Sousa V, Pereira H. Wood properties of teak (Tectona grandis) from a mature unmanaged stand in East Timor. J Wood Sci. 57(3):171–178.
Moya R, Bond B, Quesada H. 2014. A review of heartwood properties of Tectona
grandis trees from fast-growth plantations. Wood Sci Technol. 48:411–433.
24
Muller U, Ratzsch M, Schwanninger M, Steiner M, and Zobl H. 2003. Yellowing anf IR-changes of spruce wood as result of UV-irradiation. J Photochem
Photobiol B Biol. 69:97-105.
Nguila IG, Mounguengui S, Dumarcay S, Petrissans M, and Gerardin P. 2007. Evidence of char formation during wood heat treatment by mild pyrolysis.
Polymer Degradation and Stability. 92(6):997-1002.
Niamké F, Amusant N, Charpentier J, Chaix G, Baissac Y, Boutahar N, Adima A, Coulibaly S, Allemand C. 2011. Relationship between biochemical attributes (non-structural carbohydrates and phenolics) and natural durability against fungi in dry teak wood (Tectona grandis L. f). Ann For Sci. 68(1):201-211. doi 10.1007/s13595-011-0021-2
Pandey KK. 2005. A note on the influence of extractives on the photo-discolouration and photo-degradation of wood. Polym. Degrad. Stab. 87:375-379.
Rowell RM. 2005. Handbook Of Wood Chemistry And Wood Composites. CRC Press LLC: US.
Sumthong P, Gonzales RRR, Verpoorte R. 2006. Isolation and elucidation of quinones in Tectona grandis. Division of Pharmacognosy, Section of Metabolomics. Netherlands: Institute of Biology, Laiden University.
Thulasidas P, Bhat K. 2007. Chemical extractive compounds determining the brown-rot decay resistance of teakwood. Holz Roh Werkst. 65(2):121–124. doi 10.1007/s00107-006-0127-7.
Tsoumis G. 1991. Science and Technology of Wood (Structure, Properties,
Utilization). New York (US): Van Nostrand Reinhold.
Walinder M. 2000. Wetting Properties on Wood. Factors Influencing
Measurements of Wood Wettability [thesis]. KTH-Royal Institute of
Technology, Dept. of Manufacturing Systems Wood Technology and Processing: Stockholm.
Wangaard FF, Granados LA. 1967. The effect of extractives on water-vapor sorption by wood. Wood Sci Technol. 1:253–277.
Wijayanto A. 2014. Composition chimique, propriétés antioxydantes, et propriétés antifongiques de Tectona grandis et Pinus merkusii [thesis]. Universite de Lorraine: France.
Windeisen E, Klasse A, Weigner G. 2003. On the chemical characterisation of plantation teakwood from Panama. Holz Roh Werkst. 61(6):416-418.
Wu W, Giese JR, and Van Oss. 1995. Evaluation of the Lifshitz-van der Waalslacid-base approach to determine surface tension components.
Langmuir. 11(1):379-382.
25 Appendix 1 Dichloromethane extract chromatogram of long rotation (teak a) and
short rotation teak wood (teak b)
, 04-Apr-2016 + 11:50:41 20160304
6.05 11.05 16.05 21.05 26.05 31.05 36.05
Time 0
100
%
teak a dicloromethane 04 Scan EI+
TIC
6.05 11.05 16.05 21.05 26.05 31.05 36.05
Time 0
100
%
teak b diclorormethane 04 Scan EI+
26
Appendix 2 Acetone extract chromatogram of long rotation (teak a) and short rotation teak wood (teak b)
, 04-Apr-2016 + 17:58:49 20160404
6.05 11.05 16.05 21.05 26.05 31.05 36.05
Time
6.05 11.05 16.05 21.05 26.05 31.05 36.05
27 Appendix 3 Toluene-Ethanol extract chromatogram of long rotation (teak a) and
short rotation teak wood (teak b)
, 04-Apr-2016 + 19:29:24 20160404
6.05 11.05 16.05 21.05 26.05 31.05 36.05
Time 0
100
%
teak a toluene-ethanol 04 Scan EI+
TIC
6.05 11.05 16.05 21.05 26.05 31.05 36.05
Time 0
100
%
teak b toluene-ethanol 04 Scan EI+
28
CURRICULUM VITAE
Dwi Erikan Rizanti was born on August 20, 1992 in Gisting, Lampung, Indonesia. She is 2nd child of 5 children from Mr. Rizal Ependi, SPd and Mrs. Hapizoh, SPd. She attended high school at MAN 1 Bandar Lampung, where she grew up. She received her Bachelor of Forestry in Forest Products Technology Department, Faculty of Forestry, Bogor Agricultural University in 2014. She got a
scholarship from Indonesian Ministry of Education “Beasiswa Unggulan” to
continue her Master degree at Bogor Agricultural University and AgroParisTech ENGREF, Nancy, France in Double Degree Programme 2014-2016. She is listed as a student of the 2nd year master FAGE spécialité Bois, Forêt Développement
durable (BFD) of AgroParisTech 2015-2016. In the 2nd semester in AgroParisTech,
