Analisis Pengaruh Konsentrasi Natrium Hidroksida terhadap Sifat Mekanik Biokomposit Berpenguat Serat Sisal

The mechanical properties of natural fibers are continuous development as the alternatively synthetic fibers because of the natural fibers are non-corrosive, lightweight, and environmental advantages. However, these fibers have poor interfacial adhesion properties as the fibers if used as bio-composite material. This problem can be solved by the surface modification method by the sodium hydroxide treatment used to improve the mechanical properties. A sodium hydroxide concentration which it used at 0 wt%, 5 wt%, 10 wt%, and 15 wt% and the sisal fibers were soaked in that a concentration for 2 hours. Furthermore, the bio-composite fabrication is conducted by hand lay-up technique which is using both sisals as the fibers and epoxy resin as the matrix. The tensile test RTG-1250 results show that the maximum mechanical properties, such as strains, Young's modulus, and elongation, was obtained at sodium hydroxide 5 wt% than others where the values of these mechanical properties were 25.334 MPa, 16.111 GPa, and 1.572%, respectively. The morphological evaluation carried out using a scanning electron microscope showed that the alkali sodium hydroxide treatment was improved interfacial adhesion between fiber and matrix. Finally, sodium hydroxide alkali treatment of more than 5% can be able to sisal fiber cracks so that the mechanical properties of bio-composite can decrease continuously.

Effect of sodium hydroxide treatment on dry sliding wear behavior of Phoenix sp. fiber reinforced polymer composites

In this work, the effect of various concentrations of sodium hydroxide treatment (5, 10, 15 and 20%) on tribological properties of Phoenix sp. fiber reinforced epoxy composites was investigated for the first time and reported. The composites were fabricated by using compression molding technique with optimized fiber length (20 mm) and fiber volume fraction (40%). The shore D hardness of the untreated and treated fiber reinforced composites was determined. The dry sliding wear test was conducted using pin-on-disk wear testing machine at different loads (10, 20 and 30 N), sliding speeds (1, 2 and 3 m/s) and sliding distances (1, 2 and 3 km). The arithmetic mean surface roughness of the samples was measured before and after the wear test. The outcomes revealed that the concentration of sodium hydroxide treatment significantly influenced the hardness and tribological properties and surface roughness value of the fabricated composites. In particular, the composites reinforced with 15% treated fiber composites showed higher wear resistance at all operating conditions and was suggested for fabricating the friction composites for automobile and machine tool applications. The morphology of the worn surfaces of the samples was examined using a scanning electron microscope to study the wear mechanisms.

Comparison of structural, functional and in vitro digestion properties of bread incorporated with grapefruit peel soluble dietary fibers prepared by three microwave-assisted modifications

In our previous study, three kinds of grapefruit peel soluble dietary fibers (SDF) were prepared by microwave-sodium hydroxide treatment (MST-SDF), microwave-enzymatic treatment (MET-SDF) and microwave-ultrasonic treatment (MUT-SDF).

Performance of Modified Natural Zeolites by Sodium Hydroxide Treatments in The Esterification of Glycerol and Oleic Acid

Esterification is the reaction of the formation of an ester compound by reacting an alcohol compound and carboxylic acid. In this study, the performance of zeolite-based catalysts has been studied for esterification reactions. Modification of zeolite pore size was done to be hierarchical zeolite, with the aim of increasing the catalytic properties of zeolite. The modification was carried out by desilication by sodium hydroxide treatment with a variation of 0.1; 0.3; 0.5 M. The resulting catalyst was then characterized using BET and XRD. Furthermore, the catalyst was tested for activity for esterification of fatty acids and glycerol and the product was analyzed using GC-MS. Zeolite modification with sodium hydroxide has been proven to improve catalyst performance, without changing their crystal structure. The best catalytic activity was obtained on the catalyst with sodium hydroxide treatment of 0.3 M, resulting glycerol conversion of 92% and selectivity to monoglycerides of 74%.

Mercerization Effect on Mechanical Properties of Empty Fruit Bunch Fibre in Reinforcing Low Densities Lightweight Foamed Concrete

Due to the minimum cost, availability and renewable character, natural fibre had managed to grab the attention of researchers to utilize this industrial waste as industrial and structural material to restore the structures. This is due to the renewable nature of the fibre, minimal cost, low density and the amenability towards the chemical modification. The purpose of this paper is to oversee the reaction of empty fruit bunches fibre in the low densities of lightweight foamed concrete after been modified with the different percentages of alkali treatment using sodium hydroxide (NaOH). The effect of this fibre chemical treatment (2%-10% sodium hydroxide chemical treatment) on the mechanical properties of lightweight foamed concrete was investigated expansively. There were three different densities of lightweight foamed concrete (500kg/m3 , 700kg/m3 and 900kg/m3 ) used in this study. There were three different experimental test conducted to determine the lightweight foamed concrete strengths which were axial compressive strength test, flexural test and splitting tensile strength. The test result shows that 6% of sodium hydroxide chemical treatment of empty fruit bunches fibre offered the best results. The result showed that the highest strength result is obtained from 900kg/m3 density of lightweight foamed concrete with 6% sodium hydroxide treatment on the empty fruit bunches fibre while the lowest strength was obtained by 500kg/m3 lightweight foamed concrete with 0% of sodium hydroxide treatment on the fibre. Out of 257% of intensification in axial compressive strength test, 88% were showed in flexural strength test and 61% increase in splitting tensile strength test.

Flabelliferin removal by sodium salts and sodium hydroxide: Pretreatment in Borassus flabellifer mesocarp

The mesocarp of Borassus flabellifer has been proven to be a good potential as a food ingredient; however, the presence of bitterness in it is a deterrent to its acceptable application. Therefore, this study was aimed to determine the effectiveness of sodium hydroxide, sodium chloride, and sodium bicarbonate at 1% to 3% concentrations in reducing the bitter component, flabelliferin, in the mesocarp of B. flabellifer and how the pretreatment could affect the reduction of flabelliferin and phenolics contents. Eleven compounds were identified in the mesocarp by high-performance liquid chromatography-electrospray ionisation mass spectrometry (HPLC-ESI-MS/MS), which consisted of seven types of phenolics, two types of antocyanidins, and two types of steroidal saponins. The highest reduction at 46.2% of flabelliferin was obtained by 3% sodium hydroxide treatment. However, the removal of the bitter component was also concurrently resulted in a decrease of the total phenolic contents (0.16 mg GAE/g) of the sample. Mild treatment such as enzymatic treatment should be employed as the alternative method to preserve the antioxidant content in the mesocarp of B. flabellifer in order to promote its application in the food industry as a potential food ingredient.