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All Journal Jurnal Bahan Alam Terbarukan Indonesian Journal of Forestry Research Journal of Engineering and Technological Sciences Jurnal Ilmu dan Teknologi Kayu Tropis
Subyakto Subyakto
Research Center for Biomaterials, Indonesian Institute of Sciences, Jalan Raya Bogor Km. 46, Cibinong, Bogor 16911,
Agriculture, Biological Sciences & Forestry Engineering Materials Science & Nanotechnology

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UTILIZATION OF MICRO SISAL FIBERS AS REINFORCEMENT AGENT AND POLYPROPYLENE OR POLYLACTIC ACID AS POLYMER MATRICES IN BIOCOMPOSITES MANUFACTURE Subyakto, Subyakto; Masruchin, Nanang; Prasetiyo, Kurnia Wiji; Ismadi, Ismadi
Indonesian Journal of Forestry Research Vol 10, No 1 (2013): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar

Abstract

Sisal (Agave sisalana) as a perennial tropical plant grows abundantly in Indonesia. Its fibers can be used as the reinforcement agent of biocomposite products. Utilization of sisal as natural fiber has some notable benefits compared to synthetic fibers, such as renewable, light in weight, and low in cost. Manufacture of biocomposite requires the use of matrix such as thermoplastic polymer, e.g. polypropylene (PP) and polylactic acid (PLA) to bond together with the reinforcement agent (e.g. sisal fibers). In relevant, experiment was conducted on biocomposites manufacture that comprised sisal fibers and PP as well as PLA. Sisal fibers were converted into pulp, then refined to micro-size fibrillated fibers such that their diameter reduced to about 10 μm, and dried in an oven. The dry microfibrillated sisal pulp fibers cellulose (MSFC) were thoroughly mixed with either PP or PLA with varying ratios of MSFC/PP as well as MSFC/PLA, and then shaped into the mat (i.e. MSFC-PP and MSFC-PLA biocomposites). Two kinds of shaping was employed, i.e. hot-press molding and injection molding. In the hot-press molding, the ratio of  MSFC/PP as well as MSFC/PLA ranged about 30/70-50/50. Meanwhile in the injection (employed only on assembling the MSFC-PLA biocomposite), the ratio of MSFC/PLA varied about 10/90-30/70. The resulting shaped MSFC-PP and MSFC-PLA biocomposites were then tested of its physical and mechanical properties. With the hot-press molding device, the physical and mechanical (strength) properties of MSFC-PLA biocomposite were higher than those of  MSFC-PP biocomposite. The optimum ratio of  MSFC/PP as well as MSFC/PLA reached concurrently at 40/60. The strengths of MSFC-PP as well as MSFC-PLA biocomposites were greater than those of individual polymer (PP and PLA). With the injection molding device, only the MSFC-PLA  biocomposite  was formed  and its strengths  reached  maximum  at 30/70  ratio.  The particular strengths (MOR and MOE) of MSFC-PLA biocomposite shaped with injection molding were lower than those with hot-press molding, both at 30/70 ratio. The overall MOR of such MSFC- PLA biocomposite was lower than that of pure PLA, while its MOE was still mostly higher.
Bacteria as Self-Healing Agent in Mortar Cracks Nugroho, Ananto; Satyarno, Iman; Subyakto, Subyakto
Journal of Engineering and Technological Sciences Vol 47, No 3 (2015)
Publisher : ITB Journal Publisher, LPPM ITB

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2147.727 KB) | DOI: 10.5614/j.eng.technol.sci.2015.47.3.4

Abstract

This study was aimed at finding the possibility to apply Bacillus subtilis integrated into mortar matrix to act as a self-healing agent to seal cracks. Bacterial spores at concentrations of 104, 105, and 106 cells/ml were directly added into pulverized fly ash as medium to protect bacteria in high alkaline conditions. The results show that the addition of Bacillus subtilis spores into the mortar mixture enhanced the compressive strength, especially at a cell concentration of 105 cells/ml. The bacterial mortar had a small ability to recover the stiffness of the mortar, amounting to 34.85% of its original stiffness. The effectiveness of crack sealant and resistance to water flow were limited to a maximum crack width size of 0.22 mm. Physical observation showed that the bacterial mortar is characterized by calcite precipitation as a product of ureolytic bacteria. The quantity and distribution of calcite precipitate depended on the precipitation weight, gravity direction and oxygen availability. Meanwhile, chemical analysis using XRD and EDX showed that the bacterial mortar had a better crystallinity.
UTILIZATION OF MICRO SISAL FIBERS AS REINFORCEMENT AGENT AND POLYPROPYLENE OR POLYLACTIC ACID AS POLYMER MATRICES IN BIOCOMPOSITES MANUFACTURE Subyakto, Subyakto; Masruchin, Nanang; Prasetiyo, Kurnia Wiji; Ismadi, Ismadi
Indonesian Journal of Forestry Research Vol 10, No 1 (2013): Journal of Forestry Research
Publisher : Secretariat of Forestry Research and Development Agency

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.20886/ijfr.2013.10.1.11-20

Abstract

Sisal (Agave sisalana) as a perennial tropical plant grows abundantly in Indonesia. Its fibers can be used as the reinforcement agent of biocomposite products. Utilization of sisal as natural fiber has some notable benefits compared to synthetic fibers, such as renewable, light in weight, and low in cost. Manufacture of biocomposite requires the use of matrix such as thermoplastic polymer, e.g. polypropylene (PP) and polylactic acid (PLA) to bond together with the reinforcement agent (e.g. sisal fibers). In relevant, experiment was conducted on biocomposites manufacture that comprised sisal fibers and PP as well as PLA. Sisal fibers were converted into pulp, then refined to micro-size fibrillated fibers such that their diameter reduced to about 10 μm, and dried in an oven. The dry microfibrillated sisal pulp fibers cellulose (MSFC) were thoroughly mixed with either PP or PLA with varying ratios of MSFC/PP as well as MSFC/PLA, and then shaped into the mat (i.e. MSFC-PP and MSFC-PLA biocomposites). Two kinds of shaping was employed, i.e. hot-press molding and injection molding. In the hot-press molding, the ratio of  MSFC/PP as well as MSFC/PLA ranged about 30/70-50/50. Meanwhile in the injection (employed only on assembling the MSFC-PLA biocomposite), the ratio of MSFC/PLA varied about 10/90-30/70. The resulting shaped MSFC-PP and MSFC-PLA biocomposites were then tested of its physical and mechanical properties. With the hot-press molding device, the physical and mechanical (strength) properties of MSFC-PLA biocomposite were higher than those of  MSFC-PP biocomposite. The optimum ratio of  MSFC/PP as well as MSFC/PLA reached concurrently at 40/60. The strengths of MSFC-PP as well as MSFC-PLA biocomposites were greater than those of individual polymer (PP and PLA). With the injection molding device, only the MSFC-PLA  biocomposite  was formed  and its strengths  reached  maximum  at 30/70  ratio.  The particular strengths (MOR and MOE) of MSFC-PLA biocomposite shaped with injection molding were lower than those with hot-press molding, both at 30/70 ratio. The overall MOR of such MSFC- PLA biocomposite was lower than that of pure PLA, while its MOE was still mostly higher.
Physical-Mechanical Properties and Bonding Mechanism of Corn Stalks Particleboard with Citric Acid Adhesive Prasetiyo, Kurnia Wiji; Oktaviani, Linda; Astari, Lilik; Syamani, Firda A; Subyakto, Subyakto; Achmadi, Suminar S
Jurnal Ilmu dan Teknologi Kayu Tropis Vol 16, No 2 (2018): Jurnal Ilmu dan Teknologi Kayu Tropis
Publisher : Jurnal Ilmu dan Teknologi Kayu Tropis

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (38.454 KB)

Abstract

As a natural fiber and agricultural by-product, corn stalks (Zea mays saccharata) is considered as an alternative raw material to produce particleboard. Corn stalks is a good source of lignocelluloses, renewable and low cost. This research was aimed to investigate the characteristics of corn stalk particleboard with citric acid as adhesive. This study also evaluated bonding mechanism particle with citric acid and the bonds between celluloses derived corn stalk with citric acid. The boards were manufactured under the hot pressing temperature 200 oC for 10 min. The citric acid concentration was varied in 0, 15, 20 and 25 wt%. The board size and target density were (25 x 25 x 0.9) mm3 and 0.8 g.cm-3. Results showed that the physical properties of particleboards improved with increasing citric acid concentration up to 20 wt%. At the optimum citric acid content of 20 wt% could provide particleboards with the modulus of rupture, modulus of elasticity and internal bonding satisfied the requirement of the 13 type of the JIS A 5908 (2003) standard. Infrared (IR) spectral analysis from board which manufactured from isolated cellulose was mixed citric acid and pressed on temperature 200 oC showed the presence of ester linkages that the carboxyl and hydroxyl groups of citric acid had reacted with the hydroxyl groups of corn stalk cellulose.Keywords : citric acid, corn stalk, concentration, particleboard, adhesive
Characteristics of Environmentally Friendly Food Container Composite Made From Sorghum Bagasse and Citric Acid ismadi, ismadi; Kusumah, Sukma Surya; Subyakto, Subyakto; Subiyanto, Bambang; Suryanegara, Lisman; Marlina, Resti
Jurnal Bahan Alam Terbarukan Vol 9, No 2 (2020): December 2020 [Nationally Accredited - Sinta 2]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v9i02.27345

Abstract

The common food container product was made from plastic such as polypropylene, polystyrene, etc which has slowed to degrade hence affected to the environmental pollution and health disorder. Therefore, environmentally friendly food container composite is developed from sustainable resources such as sorghum bagasse and citric acid. The effects of sorghum species, sorghum particles and citric acid content on the composite properties were investigated. Local species of sorghum was used as raw material such as Super 2 in the manufacturing of food packaging.  The size and moisture content of the particles were passthrough on 40 mesh and 10%, respectively. The content of the particle was variated such as 10, 15, and 20% wt. Furthermore, citric acid was used as a binder with difference content such as 10, 20, and 30% wt.  Those raw materials were mixed with tapioca starch, polyvinyl alcohol (PVA), and glutaraldehyde. The mixing material was hot pressed at 180 ℃ for 15 minutes. The composite dimension was 12 cm x 10 cm x 3 mm. The physical and mechanical properties of the composite were carried out. Considering the properties of the composite, sorghum bagasse and citric acid are suitable as raw material of food container composite.
Hybrid Particleboard Made of Corn Husk (Zea Mays L.) and Sembilang Bamboo (Dendrocalamus Giganteus Munro): Effect of Adhesive Type and Particle Composition Prasetiyo, Kurnia Wiji; Hermawan, Dede; Hadi, Yusuf Sudo; Subyakto, Subyakto; Firdaus, Muhammad; Syamani, Firda Aulya; Astari, Lilik
Jurnal Bahan Alam Terbarukan Vol 10, No 2 (2021): December 2021 [Nationally Accredited - Sinta 2]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v10i2.31600

Abstract

Particleboard is a panel product made of wood particles or other lignocellulosic materials added with adhesive then pressed. The development of particleboard manufactured using non wood biomass has become important due to the decreased of wood as main raw material for the particleboard industry. Corn husk (Zea mays L.) and Sembilang bamboo (Dendrocalamus giganteus Munro) are lignocellulosic biomass that has  potential as  renewable materials for hybrid particleboard. The purposes of this study were to determine the suitability, the effect of adhesive type, and particle composition on physical and mechanical properties of hybrid particleboard made of corn husk and Sembilang bamboo particles. The adhesive types used were urea formaldehyde (UF) and phenol formaldehyde (PF) with 10 wt% adhesive content and the composition of corn husk : Sembilang bamboo was  set at 100 : 0, 75 : 25, 50 : 50, 25 : 75, 0 : 100 (% w/w). The target density of hybrid particleboard was set at 0.80 g/cm3. The boards were manufactured at 130 °C for UF and 150 °C for PF press temperature, 10 minutes and 2.5 MPa for the pressure of the hot press. The results showed that hybrid particleboard properties improved with increasing the amount of Sembilang bamboo particles in the board. Hybrid particleboard properties affected in ascending order were modulus of rupture (MOR), modulus of elasticity (MOE), internal bond (IB) and screw holding power (SHP). Generally, hybrid particleboard bonded PF adhesive has better properties than bonded UF adhesive. Results indicated that the addition of Sembilang bamboo particles in the mixture resulted in better properties of hybrid particleboard.
Synthesis and Characterization of Activated Carbon from Lignocellulosic Biomass: Oil Palm Empty Fruit Bunches and Mahogany Sawdust Arundina, Ria Yolanda; Permana, Indri; Togatorop, Ester Rimma Suryani; Ismadi, Ismadi; Kusumah, Sukma Surya; Budiman, Ismail; Subyakto, Subyakto; Marlina, Resti
Jurnal Bahan Alam Terbarukan Vol 10, No 2 (2021): December 2021 [Nationally Accredited - Sinta 2]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v10i2.33488

Abstract

Lignocellulosic biomass is a biological residue from the agricultural or forestry industry which is composed of polymeric cellulose, hemicellulose, lignin, and other extractive components. One of the products in the utilization of lignocellulosic biomass waste is activated carbon products. In this study, two types of lignocellulosic biomass waste were used, namely Empty Palm Oil Bunches (OPEFB) and Mahogany Sawdust (MS) to be converted into activated carbon using the hydrothermal-pyrolysis method. Potassium hydroxide (KOH) was used as an activating agent at high concentrations (50% w/w) to improve the adsorption mechanism in activated carbon material. Proximate analysis was carried out to obtain information related to yield, moisture content, and ash content. In addition, activated carbon samples were characterized using FTIR, XRD, and FESEM to observe the chemical bonds, structure, and morphology of activated carbon, respectively. The proximate analysis showed that the activated carbon sample had met the SNI 63-3730-1995 standard for technical activated carbon on the parameters of water content and ash content, while the FTIR spectrum showed the mechanism of biomass conversion from raw materials to activated carbon on a chemical bond approach. Furthermore, the XRD graph shows a reduction in the crystal size of the material from raw material to activated carbon material. Finally, the FESEM image shows a significant increase in the quality and quantity of pores on the carbon material before and after activation.
Co-Authors Ananto Nugroho, Ananto Arundina, Ria Yolanda Astari, Lilik Astari, Lilik Bambang Subiyanto, Bambang Budiman, Ismail Dede Hermawan Iman Satyarno Ismadi Ismadi Kurnia Wiji Prasetiyo Kusumah, Sukma Surya Marlina, Resti Muhammad Firdaus Nanang Masruchin Oktaviani, Linda Permana, Indri Suminar S Achmadi Suryanegara, Lisman Syamani, Firda A Syamani, Firda Aulya Togatorop, Ester Rimma Suryani Yusuf Sudo Hadi