Binderless MDF from Hydroxymethylated Kenaf Pulp

Modified lignin with improved reactivity can be a potential alternative for synthetic phenol formaldehyde resin for the adhesive of wood composite. Direct hydroxymethylation of kenaf in the present experiments was intended to increase lignin reactivity, and therefore was expected to result in satisfying properties of binderless MDF. The stem of kenaf was refined in a disk refiner and the refined fibers were hydroxymethylated in various levels of alkalinity. The concentration of NaOH during hydroxymethylation was of 3%, 6% and 12%. Wet process was applied to produce MDF (30 cm x 30 cm x 1 cm) with target density of 0.65 g/cm³. Physical and mechanical properties of MDF were measured in accordance with the standard procedure of JIS A 5905: 2003. Chemical changes in the surface of pulp and the change of board crystallinity were evaluated by FTIR-KBr method and X-Ray Diffractometry (XRD), respectively. Density, moisture content, and screw withdrawal of the board increased with increasing of NaOH concentration. Thickness swelling, water absorption, MOE and MOR increased up to 3% concentration of NaOH. The IB and heat conductivity of MDF were not influenced by NaOH concentration. Increasing OH groups due to hydroxymethylation was thought to be the origin of high water absorption and thickness swelling of the resulting boards. Higher alkalinity during hydroxymethylation stage was likely increasing cellulose crystallinity that brought about increasing board density. However, chemical modification of the fiber was thought to be more influential to the bending strength and stiffness of the resulting fiberboard. Hydroxymethylation of kenaf pulp was successfully improved board properties. Except for the moisture content, thickness swelling and internal bonding (at 0% and 3% NaOH concentration), all properties of the MDF satisfied the requirement of JIS A 5905: 2003 (type 5) standard

The Characteristic Changes of Betung Bamboo (Dendrocalamus Asper) Pretreated by Fungal Pretreatment

The fungal pretreatment effect on chemical structural and morphological changes of Betung Bamboo was evaluated based on its biomass components after being cultivated by white rot fungi, Trametes versicolor. Betung bamboo powder (15 g) was exposed to liquid inoculum of white rot fungi and incubated at 270C for 15, 30 and 45 days. The treated samples were then characterized by FT-IR spectroscopy, X-Ray diffraction and SEM-EDS analyses. Cultivation for 30 days with 5 and 10% loadings retained greater selectivity compared to that of the other treatments. FTIR spectra demonstrated that the fungus affected the decreasing of functional group quantities without changing the functional groups. The decrease in intensity at wave number of 1246 cm-1 (guaiacyl of lignin) was greater than that at wave number of 1328 cm-1 (deformation combination of syringyl and xylan) after fungal treatment. X-ray analysis showed the pretreated samples had a higher crystallinity than the untreated ones which might be due to the cleavage of amorphous fractions of cellulose. The pretreated samples have more fragile than the untreated ones confirmed by SEM. Crystalline allomorph calculated by XRD analysis showed that fungus pretreatment for 30 days has transformed triclinic structure of cellulose to monoclinic structure

Karakteristik Spektra Absorbansi NIR (Near Infra Red) Spektroskopi Kayu Acacia mangium WILLD pada 3 Umur Berbeda

Penelitian mengenai pengujian nondestruktif metode near infrared (NIR) spektroskopi di Indonesia masih sangat terbatas. Penelitian ini bertujuan untuk menentukan karakteristik spektra NIR spektroskopi (panjang gelombang 700 nm – 2500 nm) kayu Acacia mangium dari 3 umur yaitu 5, 6, dan, 7 tahun. Kayu mangium diperoleh dari daerah Maribaya, Parung Panjang, Bogor. Sampel contoh uji spektra terdiri dari bentuk solid atau padatan dan bentuk serbuk kayu. Hasil penelitian menunjukkan spektra absorban NIR sampel padatan kayu lebih tinggi dibandingkan bentuk sampel serbuk. Umur pohon untuk jenis kayu yang sama tidak memberikan informasi perbedaan pola spektra absorbansi NIR yang nyata untuk setiap lokasi panjang gelombangnya. Penelitian lebih lanjut dapat dilakukan untuk menentukan model pendugaan sifat kimia, fisis dan mekanis kayu menggunakan analisis statistik metode analisis multivariasi.Kata kunci: NIR spektroskopi, Acacia mangium, kayu solid, serbuk kayu  Characteristics of Absorbency Spectra of NIR (Near Infra Red) Spectroscopy of Acacia mangium Willd Wood from Three Different AgeAbstractResearch on non-destructive test of near infrared (NIR) spectroscopy method was still limited in Indonesia. The aim of this study was to determine near infrared (NIR) spectroscopy (wavelength range within 780 nm -2500 nm) characteristic of wood species of Acacia mangium. The samples were selected from three different ages e.g. 5 year, 6 years, and 7 years grown in Maribaya area of Parung Panjang Distric. The NIR testing samples used were solid wood and ground wood. This study resulted that there was visually no significant difference of absorbance spectra NIR patterns based on wood ages. NIR absorbance spectra had same trend for both solid and ground wood samples in a range of wavelength, although those were in different values. The NIR absorbance spectra values of solid wood samples seemed higher than ground wood samples. Further research is needed to develop predicting model of NIR spectroscopy to determine wood properties of chemical, physical and mechanical properties using multivariate analysis method

Sponge Gourd Potential for the Raw Material of Paper and Dissolving Pulp

Sponge gourd (Luffa cylindrica) provides a sustainable and cheap source of lignocellulosic materials potential for the raw material of paper and dissolving pulp. In the present works, sponge gourd fruits 5 and 8 months old were pre-hydrolyzed in an acidic (pH of 5) and neutral (pH of 7) at 165 C for 3 hours, and successively soda pulped at a maximum temperature of 170 oC for 4 hours with 20% active alkali. The resulting pulp was bleached by the D0E1D1E2D2 method. The bleached pulp was chemically analyzed to evaluate its feasibility for dissolving pulp based on the requirement of SNI 14-03-1989. The pulp feasibility for paper materials ware based on the measurement of fiber dimensions, fiber derivative values, and the strength properties of the pulp. It was found that the a-cellulose content of the sponge gourd coir was high compared to the requirement of SNI 14-03-1989. However, it did not satisfy the requirement of dissolving pulp due to its high extractives, ash, silica content, and low viscosity. The fiber of sponge gourd coir was classified into the quality class of II with intermediate pulp strength.  

Trace Elements Measurement of Mangium Wood (Acacia mangium) by AAS

The ash and metals content of Acacia mangium Wild was determined following standard procedures of TAPPI T211 om-93 test method and wet ashing procedures with HNO3 and HClO4 solution, respectively. Measurements of trace elements were carried out by the use of atomic absorption spectrometry (AAS). Although it was fluctuating, the lowest ash content was found in a 5 years old wood and then tended to increase in older three. In the 3 and 5 years old wood, the ash content decreased from upper end to the lower end of the stems. In the 7 and 9 years old wood, the lowest ash content was in the middle part and it tends to increase to the lower end of the stem. Ash content of sapwood was higher than that of heartwood. The content of Mg decreased with increasing age of wood, and other metals tended to increase with the increase of wood age. Metallic components of acacia wood tended to accumulate more in sapwood compared to these in heartwoods. Vertically, the content of Mg and Cu decreased from upper end to lower end of the stems, and in contrary to these of other metals.Key words: atomic absorption spectrometry, Acacia mangium, closed loop cycle, metallic contents, oxygen-based bleachin

The Characteristics of Beaten and Unbeaten Mixed Tropical Hardwood Kraft Pulp

In the present works, pulp fibers were fractionated with Bauer McNet fiber fractionators and were classified into long fiber (R30), short fiber (P30/R100) and fines (P100/R200). Water retention value (WRV), dimensions measurements and pulp viscosity of fibers were determined based on of the modified method of Thode et al. (1960), the standard method of SII 1883-1986 and TAPPI 230 om-94, respectively. The measurement of fiber dimensions were done on 200 individual fibers. The increase of short fiber fraction clearly indicated fiber shortening effect of beating process. Beating processes increased WRV of fines above that of long fiber fraction. Beating of pulp did not significantly change the derivative value of fibers, but significantly decreased pulp viscosity

Trace Elements Measurement of Mangium Wood (Acacia Mangium) by AAS

The ash and metals content of Acacia mangium Wild was determined following standard procedures of TAPPI T211 om-93 test method and wet ashing procedures with HNO3 and HClO4 solution, respectively. Measurements of trace elements were carried out by the use of atomic absorption spectrometry (AAS). Although it was fluctuating, the lowest ash content was found in a 5 years old wood and then tended to increase in older three. In the 3 and 5 years old wood, the ash content decreased from upper end to the lower end of the stems. In the 7 and 9 years old wood, the lowest ash content was in the middle part and it tends to increase to the lower end of the stem. Ash content of sapwood was higher than that of heartwood. The content of Mg decreased with increasing age of wood, and other metals tended to increase with the increase of wood age. Metallic components of acacia wood tended to accumulate more in sapwood compared to these in heartwoods. Vertically, the content of Mg and Cu decreased from upper end to lower end of the stems, and in contrary to these of other metals

Sifat Dasar Tanaman Mengkuang (Pandanus artocarpus Griff) Basic Properties of Mengkuang Plant (Pandanus artocarpus Griff)

The aim of this research were to determine the  extractive,  α-cellulose, hemicellulose, lignin, and sugar composition of hemicelluose for raw materials and pulp of mengkuang (Pandanus artocarpus Griff) leave and stem. Delignification was carried out by alkaline process with NaOH 20% and 25% at 170 oC for 4 h. The chemical and physical analyses were done using Fourier Transform Infrared Spectroscopy, X-Ray Diffraction, High Performance Liquid Chromatography, and Scanning Electron Microscopy. The leaves and stem of mengkuang  containing extracts of 6.99% and 4.80%, cellulose 35.02% and 40.29%, hemicellulose 33.12% and 31.19%, lignin 29.10% and 26.84%, respectively. The syringyl, guaiacyl, and p-hydroxyphenil composition  in mengkuang leaves and steam  were 40.00%, 41.82%, 19.24% and  39.81%, 41.82%, 18.37%. The hemicellulose in the leaves and stem consisted of glucose, arabinose, xylose, mannose, rhamnose, and galactose. The highest pulp yield (41.71%) was obtained from pretreatment of 20% NaOH in the stem. Pulp of leaves and stem contained α cellulose, hemicellulose, and total lignin content of 88.19%, 7.95%, 14.36%, and 88.27%, 10.17%, 13.83%. The highest crystallinity of pulp (70.00%) was obtained from the stem at a concentration of 25% NaOH, and the lowest (58.18%) was obtained from the leaves at a concentration of 25% NaOH.

Steam and Microwave Pretreatments in the Preparation of Bioethanol from Sugar Palm Kernel

It is paramount to develop bioethanol production based on the utilization of less important carbohydrate based feedstock such as the sugar palm kernel. In the present works, the kernel powder of sugar palm was hydrolyzed by enzymatic and acidic procedures heated either by autoclaving or microwaving. Fermentation of the resulting reducing sugars was then carried out by Saccharomyces cerevisiae at the concentration of 3, 10, and 17% for 24, 48, and 72 hours. It was found that the highest hydrolysis efficiency was by autoclaved acid hydrolysis (92.52%). On the other hand, the highest fermentation efficiency was obtained by 24 hours fermentation with a 17% S. cerevisiae of the resulting sugar from autoclaved enzymatic hydrolysis (97.36%), and the highest ethanol yield was obtained from autoclaved acid hydrolysis fermented for 72 hours with 17% S. cerevisiae (76.49%).  Keywords: bioethanol, fermentation, hydrolysis, S. cerevisiae, sugar palm kerne