Effects of Crude and Partially Purified Mannanase on the Fibre Content of Palm Kernal Cake/Expeller

Palm Kernel Cake/Expeller (PKC/E) is an agricultural waste of palm oil mill which contributed about 2.2 million tones in 2007 in Malaysia. It is an important ingredient for the formulation of animal feed instead of corn and soybean husk. The PKC/E fibre composed mainly of galactomannan type of hemicelluloses, which can barely be consumed by non-ruminant (monogastric) animals. Mannanase is a major extracellular enzyme which is secreted to convert mannan into simple sugar of mannose. In this study, Aspergilus niger FTCC 5003, a mannanase producer and PKC/E as a sole carbon source were fermented in 500 mL shake flask using the optimised parameter conditions for 10 days and the culture broth were collected for hydrolysis purpose. Purification of the mannanase from submerged fermentation of PKC/E obtained from fermentation A. niger FTCC 5003 was also carried out. Crude and partially purified enzymes were employed in this study to degrade PKC/E using enzymatic hydrolysis technique to compare with fermented PKC/E. The characteristic of palm kernel cake under fermented and hydrolysed conditions were studied under Scanning Electron Microscope (SEM) and the Near Infrared System (NIR) was used to perform proximate analysis of quantitative parameter. SEM showed fermented PKC surface structure were significantly degraded compared with the hydrolyzed palm kernel. The results of Near infrared reflectance spectroscopy (NIRS) proved that the crude fiber (CF) of palm kernel cake was reduced by enzymatic hydrolysis. The ether extract (EE) or crude fat which contained fat soluble vitamin showed the highest in hydrolyzed palm kernel cake. Partial purification of mannanase enzyme, produced by A. niger FTCC 5003 was achieved by fractional precipitation with ammonium sulphate and Tangential Flow Filtration (TFF) ultrafiltration. The purification of mannanase collected from TFF ultrafiltration was achieved with 4.8 fold of purification and 32% recovery whereas the purification of mannanase precipitated by ammonium sulphate was achieved 9.89 fold of purification and 28% recovery. The molecular mass determinations of with partially purified mannanase were estimated as 32 kDa by SDS-PAGE. The optimal temperatures of the purified mannanase was 45°C and stable at 40-50°C, and the pH optimum was at pH 4-6. However, it was most stable at pH 3-7

繊維強化プラスチックのナノフィラーとして効果的な利用に向けたセルロースナノファイバーの表面機能化

Cellulose nanofibre (CNF), which is produced from lignocelluloses, has been growing exponentially as a low-carbon material because of its relative ease of high specific surface area, high strength and stiffness, lighter in weight and biodegradability. This cellulosic fibre has been studied intensively for fibre reinforced polymer composites as outstanding reinforcing potential instead of glass or carbon fibre. Due to hydrophilicity derived from hydroxyl groups in the structure and inherent tendency to form a strong network held through hydrogen-bonding, CNF is difficult to disperse in almost of the hydrophobic polymer matrix. Therefore, this study focused on surface modification strategies to expand the applications. The present work aimed to investigate the surface modification of CNF by new greener strategies and prepare environmentally friendly next-generation fibre reinforced plastics. The surface modification of CNF was easily performed by optimizing the modification method with acid. Surface modification using an acid treatment such as acetic acid, phosphoric acid, and sulfuric acid successfully converted from the hydroxyl group to the ester group in the CNF, confirmed by FT-IR and SEM-EDS. Moreover, the XRD analysis revealed that this treated CNF was the cellulose type I even after acid treatments. The acid treatment method could improve interface adhesion between CNF and polymer matrix. The dispersibility of CNF in the silicone elastomer as a polymer matrix could not see agglomerated CNF compare to unmodified CNF in the matrix, respectively. The mechanical properties of the silicone composite also improved. Therefore, acid treatments have the potential to be an effective method as a surface modification of CNF. In order to compare the performance of CNF dispersibility in the polymer matrix and mechanical properties, acetyl cellulose as a commercial product was investigated to prepare fibre reinforced plastics with polyurethanes (PUs). Thermoplastic resin as a polymer matrix for fibre reinforced plastics is major activities in this research field. On the other hand, CNF can be worked as a network agent for thermoset resin such as PUs, polyurea, and epoxy resin. Therefore, acetyl cellulose was adopted due to less hydroxyl group as reactive sites to the isocyanate group in PUs because of suppression of networking. Though some remained hydroxyl groups in acetyl cellulose were reacted with isocyanate group in PUs monomer to make a network, molecular weight of PUs was hardly grown by networking. However, this issue could overcome after modification reaction conditions. These composites showed enhancement of mechanical properties and transparent film after hot-pressed moulding. Mechanical performance of PUs and transparency of moulding film to proof dispersibility of fibre in the PUs matrix was investigated by CNF, and phosphoric acid-treated CNF to compare with the acetyl cellulose PUs. Since agglomeration has occurred through hydrogen bonding between hydroxyl groups in cellulose structure, another material as an intercalator was mixed due to preventing hydrogen bonds between celluloses. Silica/CNF as a filler was successfully prepared using ethanol/water mixed solvents at room temperature without a catalyst. This method prevented the CNF from agglomeration when drying and enhanced the dispersion of CNF in the hydrophobic polymer. Polypropylene (PP) as a polymer matrix was melt blending with silica/CNF filler. It significantly increased the mechanical properties of the composite. In conclusion, this study provided to overcome in greater depth bothersome of CNF to prepare fibre reinforced plastics which can be shown to enhance mechanical performance due to prevent agglomeration of CNF from a hydrophobic matrix. The resulting products and method can expand and contribute to an application to replace existing materials.九州工業大学博士学位論文 学位記番号：生工博甲第397号 学位授与年月日：令和3年3月25日1: Introduction and Literature Review|2: Tailored Higher Performance Silicone Elastomer With Cellulose Nanofibre (CNF) Through Acidic Treatment|3: Enhancing Mechanical Properties of Polyurethane with Cellulose Acetate as Chain Extender|4: Covalent Incorporation of Cellulose Nanofibre (CNF) Into Polyurethane Elastomer and The Effect on Mechanical Properties|5: The Design of Dry CNF Filler by Hybridization with Silica Particle for Moulded Polypropylene Composite|6: Conclusion and Recommendations九州工業大学令和2年

Facile Preparation of Cellulose Fiber Reinforced Polypropylene Using Hybrid Filler Method

Dried hybrid fillers comprised of silica/CNF were successfully synthesized in ethanol/water mixed solvents at room temperature without the usage of any precursor. The as-prepared fillers were incorporated with polypropylene (PP) as a polymer matrix through a twin-screw extruder. From surface morphology analysis, the agglomeration of the silica/CNF hybrid fillers was prevented in the PP matrix and they exhibited moderate transparency, around 17.9% and 44.6% T at 660 nm. Further, the chemical structures of the polymer composites were identified by Fourier transform infrared (FT-IR) analysis. According to thermogravimetric analysis (TGA), the insertion of silica as a co-filler to the PP matrix resulted in an increase in its degradation onset temperature and also thermal stability. In addition, the mechanical properties of the PP composites also increased after the blending process with the hybrid fillers. Overall, sample PP-SS/CNF exhibited the highest tensile strength, which was 36.8 MPa, or around 73.55% compared to the pristine PP. The improvements in tensile strength were attributed to good dispersion and enhanced efficiency of the stress transfer mechanism between the silica and the cellulose within the PP matrix. However, elongation of the sample was reduced sharply due to the stiffening effect of the filler

Facile preparation of cellulose fiber reinforced polypropylene using hybrid filler method

Dried hybrid fillers comprised of silica/CNF were successfully synthesized in ethanol/water mixed solvents at room temperature without the usage of any precursor. The as-prepared fillers were incorporated with polypropylene (PP) as a polymer matrix through a twin-screw extruder. From surface morphology analysis, the agglomeration of the silica/CNF hybrid fillers was prevented in the PP matrix and they exhibited moderate transparency, around 17.9% and 44.6% T at 660 nm. Further, the chemical structures of the polymer composites were identified by Fourier transform infrared (FT-IR) analysis. According to thermogravimetric analysis (TGA), the insertion of silica as a co-filler to the PP matrix resulted in an increase in its degradation onset temperature and also thermal stability. In addition, the mechanical properties of the PP composites also increased after the blending process with the hybrid fillers. Overall, sample PP-SS/CNF exhibited the highest tensile strength, which was 36.8 MPa, or around 73.55% compared to the pristine PP. The improvements in tensile strength were attributed to good dispersion and enhanced efficiency of the stress transfer mechanism between the silica and the cellulose within the PP matrix. However, elongation of the sample was reduced sharply due to the stiffening effect of the filler